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 Tuning a New World of Computer Audio Playback

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Sonic.beaver



Posts : 2112
Join date : 2009-09-18

PostSubject: Tuning a New World of Computer Audio Playback   Fri Feb 05, 2016 11:16 am

Greetings Michael, Hiend001 and Zonees  cheers  cheers  cheers

Here starts a new adventure for Sonic – Tuning a New World of Computer Audio playback.

While this thread will primarily document my adoption of computer-based audio storage and playback Sonic will also cover other aspects of my Tune Journey such as acoustic treatment, equipment tuning and of course Sonic’s most liked LP, SP and 78 rpm playback.

First Sonic needs to salute and thank Hiend001 for encouraging me and giving me tips to get me started with disk storage and computer playback. Also there is a good friend who is a computing and network specialist I too must thank who has assisted me with the minutiae of set up.

So where did Sonic make the start?

I followed Hiend001’s lead and basically bought his starting system.

Laptop: ASUS X455L

CPU: Intel i5 5200U up to 2.7GHz

Memory: 8GB with HDD 1TB capacity

OS: Windows 8.1



Notice from this picture that Sonic even got what seems like the same wooden stool that Hiend001 uses to support his ASUS X455L.

Ripping software: Exact Audio Copy

Playback: Foobar2000 v1.3.9

DAC: none yet, Sonic is testing out some borrowed units

Ripping my CD collection to FLAC has been on since the first week of January, a few at a time which takes between 8 to 14 minutes per CD.

Sonic then took the first attempt at playback through my system using a borrowed DAC – an AUNE 24 bit/192 khz unit using the AUNE freebie USB connector.  



The First Listen

The first attempt at music playback through the AUNE 24/192 was awful  No

The sound was compressed, artificial, the banana soundstage was back, the mid bass was rolled off (though the lowest bass that activated the Janis W-1 was there in a good quantity), details in the music performances that Sonic knew were there were inaudible – things like a violin bow brushing a music stand, performers’ breathing, foot taps, sundry coughs and such like. This is exactly what some audiophiles told me what computer audio would sound like which is a lifeless approximation of a recording.

A return to physical CDs played through the Sony BDP380 blu ray player was such a relief.

Sonic shakes head.

This cannot be the whole picture given that Hiend001 showed that the sound from computer playback can be so good that he retired his Magnavox DVD player.

Digital is unfamiliar ground for Sonic so there is so much to learn  study

Sonic knows a new adventure has started…..

Sonic
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tjbhuler



Posts : 228
Join date : 2015-02-13

PostSubject: Re: Tuning a New World of Computer Audio Playback   Sat Feb 06, 2016 2:00 am

Hi Sonic

Great thread you have started here, I have also been keeping an eye towards this new trend on Computer Audio. I have came across and heard few setups and yes they can sound great Smile . However I have also came across few that sounds dry, analytical with midrange glare that shuts you off from listening more than 10 minutes.

After lengthy discussion with some of those successful computer audiophiles friends of mine, they have mentioned that it has got to with the compatibilty issues (16, 24 and 32 bits conversion) in the software and optimising them (usb 2.0, toslink, optical) especially when using foobar and j-river. Good news is there are loads of articles that solves most of this issues. Another thing if you are using a PC base source make sure to minimise or switch off the usage of other ongoing programs in the background they can degrade the sound profoundly.

I have been in a look out for a cheap affordable DAC just to try out and so far I have purchased Hifimediy (http://hifimediy.com/Sabre-9018-DAC this is what I got for $69 Smile ) but there are newer ones which I have never tried. A few more DAC's that might pique your interest in the future are Gustard x12 and x20, Musical Paradise MP-D1 24Bit USB, iFi, Audio Gd NFB7 and Grant Fidelity. These are few DAC's that are affordable and have been getting good reviews. I have a friend in Singapore who recently told me that he is getting an R2R Soekris 0.05% using amanero USB I2S DAC/pre made it is relatively cheap and looks very promising.

Another topic you should look at since you are embarking this journey is Ambiophonics. Yes I have it and it does make you feel like you are in a whole new level of stage presentation but the speakers have to be placed very near together. I have not done that in my home setup but in my desktop setup i have tried it and it works really well. Key word here is "miniambio" a device that you plug in after your DAC. It is something like a time alignment kind of processing but works differently.

I am pretty sure with MG's products and the tune ways you will be getting good vibes in no time. I am very excited for you making this journey.

Regards

Tj
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Sonic.beaver



Posts : 2112
Join date : 2009-09-18

PostSubject: Re: Tuning a New World of Computer Audio Playback   Sat Feb 06, 2016 8:52 am


Hello tjbhuler!

Welcome to Sonic's new thread and making those suggestions of DAC's I might try.

Now Sonic has a lot to learn about digital. I agree that the big disappointment Sonic is facing is some kind of interface issue. One thing I know is the problems with digital occur at the A to D conversion and then at the D to A conversion. The information once in 001000100100111s can be moved around or files duplicated sequentially thousands of times and gen 1 file and gen 10,000 file will be identical. But once that file is played back through a Foobar2000, Windows media player, Media Money then all sorts of things can go wrong and compromise the the sound.

Sonic does wonder why the borrowed 24 bit/192 khz DAC sounded so bad in my system while it is an excellent headphone DAC driving a pair of top of the line Sennheiser and sounding very good in that person's system.

Sonic will be trying another borrowed DAC with a very different topology and will report on how that goes in a bit. Of course I would like to try the AUNE i2s which Hiend001 got such excellent results with (but it is not available in the stores here for another couple of weeks).

For certain, the sound from computer playback via a DAC has to be a lot better than what I am hearing now through the 24/192 DAC for me to retire my Sony blu ray player and use FLAC files for music storage and as a source.

Sonic

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Sonic.beaver



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Join date : 2009-09-18

PostSubject: Re: Tuning a New World of Computer Audio Playback   Sun Feb 07, 2016 9:42 am

Greetings Zonees

Here is a description of the Tune Hiend001 taught Sonic in three easy steps:

1.      take a solid core wire like Mr Green’s T1, cut a 4 inch length as a start

2.      bend the wire in half, strip insulation off the ends about 3/8 to ½ inch and twist the bare wire together

3.      connect this to the Minus/Black colour coded terminal of your subwoofer, play music

The wire widget looks like this:



The sound of your subwoofer will tighten up. Give it a try and you can later try different lengths of wire or cable twists.  Tune Sifu/Sensei Hiend001 discovered this and got good results in his wonderful system.Sonic found the bass of the Janis W-1 tightened up a lot too – I needed to retune the subwoofer level settings.

And Heind001 has more exciting tunes he is creating!  Watch his thread.

The DAC Test
For Sonic, my first attempt at computer audio playback using a 24/192 DAC produced poor results.  Now I have borrowed another DAC, this one with a very different design approach.  If this works, the Computer Music Playback adventure will proceed. If it disappoints Sonic will fold my losing hand here, early in the game with little sunk time and costs.

Will give the first test report tomorrow.

Sonic
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Hiend001

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Posts : 109
Join date : 2013-03-24
Location : Singapore

PostSubject: Re: Tuning a New World of Computer Audio Playback   Sun Feb 07, 2016 10:46 am

Hi Sonic,

Step 2 - Don't twist the bare wire together. Just insert both ends to negative terminal (shorted).

Don't give up look at my posting tips on how to configurate the apps setting.
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Sonic.beaver



Posts : 2112
Join date : 2009-09-18

PostSubject: Re: Tuning a New World of Computer Audio Playback   Mon Feb 08, 2016 9:40 am

Greetings Michael and Zonees!

This might be a surprise – the DAC Sonic borrowed is an Audio Note 0.1x DAC a design by Peter Qvortrup and co in the UK.  Here is what the machine looks like and where Sonic tried it at the start of testing:



And after that initial set up, Sonic removed the Sony blu ray player and placed the DAC here for more concerted (sic) listening:



Sonic linked the AN 0.1x with the AUNE stock freebie USB cable to the computer and with Picasso cables by Michael Green to the Quicksilver preamp (RCA plugs inserted halfway into the jacks at the DAC and preamp ends).

After a two hour warm up on idle, Sonic played the FLAC file of Handel’s Wassermusick (Pinnock, English Concert – ARCHIV).  

What I heard in the first moments was good – much better than with the 24/192 DAC.  Then as warm up and more listening proceeded of ripped files, Sonic noticed I am getting a sound that is better than with the Sony blu ray player  Very Happy  Yes and after about another four hours of musick processing, Sonic is happily puzzled – I am hearing digital with an easy musicality I have not heard before.

This is an ease in the flow of the musick that  Sonic is familiar with listening to analog but not with digital at any price point.  The ASUS X455L with the AN 0.1x DAC had, compared to the CD player offered better dynamics, detail, treble sweetness and “whiff of reality” particularly on voices on FLAC file after file of the handful of CDs ripped.  The details in the reference recording that were absent in the 24/192 playback are audible again and this time set in an acoustic space.

Sonic will rip more CDs and test through this week – this week has lots of holidays since it is the Chinese Lunar New Year here – and as it looks like Sonic's Computer Audio Playback project looks like a GO.

Yet there is a puzzlement – which Sonic would like to hear some thoughts from Michael, Heind001 and other Zonees and especially Dr Stesiak (where are you sir?).

The puzzlement is this:  my system fell apart using a 24 bit/192 khz DAC and then sounded very nice with the AN 0.1x which is a 16 bit DAC using the old Philips TD1543 chipset along with Audio Note's 1x oversampling “Direct to Disc technology” which means no oversampling and no digital "brickwall" filter, just some sort of analog 3rd order filter beyond 22 khz, with a tube analog output stage using a 6111WA miniature double triode…..on paper it should be bested by the 24/192 convertor, and here is Sonic hearing very nice musick with the 16 bit machine decoding the 010010001100001s.

Sonic is listening now to a file of old Frank Sinatra songs like Stormy Weather and Begin the Beguine and such. This CD was only good for dinner music played softly, the whole thing becoming hard and artificial when played at listening levels.  No more.  Sinatra’s voice is warm and crooning, the orchestra though slightly distorted on peaks is natural in tone and there is bass along with dynamics!

Playing my ripped copy of Neil Young’s After the Goldrush (now there’s a masterpiece for you!), the gentle vibraphone giving atmosphere to I Believe In You and the low bass note in Southern Man that anchors the song and resolves the harmonic movement  

So much for Sonic to learn about digital and how to replay it!

“There is something going on here, what it is ain’t exactly clear…..” (Stephen Stills)

Sonic


Last edited by Michael Green on Wed Feb 10, 2016 2:05 pm; edited 2 times in total (Reason for editing : Additional text added)
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Sonic.beaver



Posts : 2112
Join date : 2009-09-18

PostSubject: Re: Tuning a New World of Computer Audio Playback   Tue Feb 09, 2016 7:56 am

Greetings Zonees

Sonic is doing more research into my experience with the DACs – certainly my initial success with the Audio Note 0.1x does not mean Sonic would rule out the AUNE i2s 32/384 that Hiend001 has found such great success with.  It is just down to the way I can get to listen to the AUNE in this system and make comparison with the sound Sonic is getting now.

This evening I played the album by Joe Farrell Quartet with John McLaughlin – good presence and nice bass foundation, natural cymbals with sheen.

Then Julie London – At Home – where she sings “Everything Happens to Me”. I can understand why so many Japanese audiophiles bow at hearing the singing of this woman.  

 

The sound is good!

As I researched, Sonic observes there are various theories and views on whether to design DACs with longer bit words and oversampling (eg: 24/192) or to go without oversampling like 16/44.1 and no upsampling and ditch the digital brickwall filter.  Sonic admits I don’t understand the stuff yet but I have read and will post the views of Peter Qvortrup/Andy Grove and Kusunoki-san of 47Labs to give Zonees insight into their thinking.

Ultimately, what drives Sonic’s choice of DAC will be three things:

a.      beautiful playback of musick in the broadest sense (as opposed to getting some things right and everything else wrong)

b.      neutrality of sound rather than the device having a designed-in sound of its own that is overlaid on everything played through it

c.      tunability of the device – a device that is built simple enough without blockages that prevent it from being tuned and lifted to another level using Michael’s devices like wood pucks, cones, springs, top tunes and his Powerful Tune Principles (crack screws, remove rubber feet, removal of ferrite beads – ferrite beads are particularly damaging to the sound in Sonic’s opinion – cutting cable ties, untangling wire bunches, removing unnecessary cosmetic features that add mass, removing chassis damping like stick-on bitumen pads and such-like).

Sonic
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Sonic.beaver



Posts : 2112
Join date : 2009-09-18

PostSubject: Re: Tuning a New World of Computer Audio Playback   Wed Feb 10, 2016 9:02 am


Greetings Zonees

Here is something I found on 1x oversampling and digital filterless DACs -- its from Audio Note UK's website. Interesting reading even though it was written by P Qvortrup about a much more expensive DAC a long time before the AN 0.1x was brought into production. The bits Sonic underlined are things I learnt from this article.

The musick from Sonic's system is good. On Friday, I will discuss some rudimentary tuning of this device. Nothing that requires that opening up the machine since Sonic doesn't own the AN 0.1x though if the sound gets any better than this with Tuning, set up and settling, Sonic may be buying Audio Note.

Sonic

-------------------------------------------------------------------------------------------------

Article by Peter Qvortrup, owner of Audio Note UK –The Thinking Behind the DAC 5

While we all wait for the brave new world of DVD, with its many proposed (imagined??!) benefits to sound quality, Audio Note is introducing a highly innovative and unusual addition to existing digital converter technology.

The question is, will the one times oversampled D to A converter with no digital filter make a further contribution to 96kHz/24Bit technology or extend the life of the existing 16Bit system?? It seems to me that one of the main purposes of 24/96 is to reduce the effect of the steep digital filtering used in the original 16Bit/44.1KHz system, so why has no-one first tried to remove the digital filter to see whether it really did any damage or not.

A brief technical discussion follows below:

Digital Audio recording consists of measuring (sampling) the amplitude of the audio waveform at regular intervals and storing the measurement results in the form of binary data.

A digital to analogue converter generates an output which bears a direct relation to the digital data it is presented with, and hopefully if all goes well we retrieve the original analogue signal.

The sampling rate is the rate at which measurements are made and the resolution is the accuracy of these measurements. The greater the sampling rate, and the greater the resolution (number of "Bits") the closer we theoretically get to the original, and infinite amounts of each would result in a perfect recording, this has been the limiting factor sofar, because more resolution and higher sampling rate means more information which in turn requires greater storage space and thus greater cost.

The engineers who originally specified CD decided upon 44.1kHz sampling rate and 16 Bits (65536 discrete levels) of resolution were aiming at good recording time on the disc combined with acceptable cost within the technology available at the time (1982/83). This just about gets us to the generally accepted 20kHz upper hearing limit and gives acceptable dynamic range and distortion, but only just.

Due to the limited sampling rate of 44.1kHz the actual bandwidth of the system is limited to a theoretical maximum of 22.05kHz (half the sampling rate). If a digitally recorded signal is played back above the high frequency limit there is a lot of signal related noise which is generally considered to be undesirable. In fact, if you observe a 16Bit 44.1kHz encoded signal which has been directly converted by a D to A converter without filtering it looks a real mess. The current wisdom is to use a digital filter which interpolates the 16Bit/44.1kHz signal to a higher sampling rate and to a seemingly higher resolution. Commonly the interpolation is 8 times oversampling (to 352.8 kHz) and to 18 or 20 Bits of resolution, no information is added, the filter mathematically joins the "dots". Then after the interpolated signal has been converted to analogue an analogue filter is used to put the final polish on the signal.

As the theoretical maximum frequency limit is 22.05kHz and the required bandwidth is 20kHz the digital filter has to cut off very very quickly. In fact the popularity of the digital filter today is entirely due to the impossibility of designing an analogue filter which can roll off so fast, and without phase distortion and time related problems. The digital filter uses a mathematical function called a sync function which gives the required "brickwall" roll-off and with no theoretical phase distortion. The sync function is an impulse which starts at time Zero and ripples off infinitely into the future, and the past!! Of course this is impossible in reality and the filter uses a part of the function and feeds the data into one end. Even though the filter only uses a small part of the sync function it must still be large enough to be effective at filtering and this means that it is usually several milliseconds long, regardless of the duration of the signal itself.

At Audio Note we have long pondered the question of how much damage the signal suffers at the hands of this filter function and the unavoidable time smearing it introduces. To give you an example, if an impulse lasting only one sample is fed into a digital filter, it gets smeared out into a ringing signal several milliseconds long, hardly supporting claims of accurate reproduction, or as we say here at Audio Note; time waits for no-one, not even the "perfect" digital medium. Time displacement is the greatest cause of audible anomalies in audio reproduction and always has been.

Whilst we are not alone in questioning the effects of the siny function and the digital filtering universally used in all CD-players and D to A converters, we are the only manufacturer unconventional enough to have grasped the nettle properly and removed the digital filter altogether, in an attempt to answer the central question; "how else do you establish with any accuracy exactly what the digital filter actually does to the signal and is there an alternative method of filtering that would preserve the signal better??"

Ask yourself why Audio Note is the only company to take the natural consequence of the above question, why has none of our esteemed competition, who have claimed numerous advances in digital technology over the past few years, not taken this logical step??

After much trial and error we found a way of removing the digital filter and incorporating a carefully designed analogue filter after the D to A conversion. Needless to say, this goes so completely against the grain of all current opinion because a lot of the spurious signals above 20kHz are still present in the output of the converter after the analogue filtering. The filter is a 3rd order design with a silver wired inductor and silver capacitors and is so designed to slowly attenuate the higher harmonics in a natural way, preserving as much of the musical waveform as possible, each filter is dynamically matched to within 0.5dB of its partner in the other channel across the full frequency spectrum, to achieve best possible channel balance.

Rather than use an off the shelf voltage regulator chip for the low voltage digital and analogue power supplies for the DAC we designed a unique discrete shunt regulator circuit, and use only the finest components throughout. In fact the DAC 5 power supplies take up more than 2/3rds of the substantial chassis. After the signal leaves the filter it is passed to a valve output stage, similar to that used in the M5 pre-amplifier, and is transformer coupled to the output, allowing both balanced and single-ended operation.

So how does the Direct Line DAC 5 converter with no digital filter and one-times oversampled D to A converter sound??

Let me first give you some background to what I believe matters in music reproduction and how I have arrived at the evaluation criteria we use at Audio Note.

It is no great secret that ever since Digital Audio was introduced in 1983, I have seriously questioned the validity of the claims that the technology would deliver the "Perfect Sound Forever" that launched the technology, I, and many others with me, found analog reproduction far more "real", satisfying and authentic, not to mention less fatiguing.

The main criterion I have always used when evaluating any hi-fi system or component is that when playing different pieces of software (whether LP or CD) the better system or component is the one that individualizes the sound from each record the most, or in other words makes you sense each recording as a different and individual musical "event".

This evaluation system is based on a fundamental analysis of recording in all its forms that concludes that all we really know about recordings, is that they must sound different from each other, the conclusion is based on the indisputable fact that each piece of software was done at a different time in a different location, with different microphones, cables, mixers, tape recorders and they were recorded by different people to any other recording, furthermore the software was manufactured by different cutting and pressing machinery at different plants and as a result must have an individual character or "signature" uniquely its own.

I call this method of differentiation "Comparison by Contrast" and with this tool in hand (or should I say ear??) I have spent many years searching out the "better", more accurate (you will notice that the term used is more accurate, not accurate in its absolute sense, because total accuracy does not exist in recording or music reproduction, it is an unachievable goal, that will never be a reality, no matter how much the marketing men of the hi-fi industry would like you to believe it is) audio components and technologies in a largely selfish quest to improve the reproduction of my own record collection.

I made this pursuit my livelihood in 1977, when I left my career as a broker with a large multinational shipping company.

Back to the main subject, by the criteria outlined above, CD fails miserably compared against even quite cheap analog component hi-fi, and I have always thought that this failing was inherent in the medium itself, i.e. the fact that the musical signal is broken down into little "bits", with poor resolution at low levels, which is after all the entry point of the musical signal (it is often forgotten that music starts from silence, not from somewhere up the amplitude scale, the assumption is often made that what we hear at the beginning of a note is what was recorded and the words "I hear more detail" assumes that we somehow know what is supposed to be there, which we certainly do not, what the reviewer should perhaps say is I hear more contrast!) it never seems to occur to anyone that the starting parts of the musical note might be missing.

The quiet background of the digital medium should therefore allow the best possible low level detail, but it does not, low level acoustic information like hall ambience is almost completely lost on most digital recordings (it is a little better on good analog recordings transferred to CD, indicating that the digital recording process is at least partly to blame), modern recording techniques do not help, as multi mic'ing, digital mixing and other technical gadgets used in the studio, "help" the recording engineers do their job speedily and within budget, a far cry from the simplicity, dedication and time that went into every recording made from the early acoustically recorded 78's to the earliest LP's) and this real acoustic information is replaced by a varyingly degree of hard and bright electronic echo, which makes most CD listening fatiguing, unless of course the system used tailors the high frequencies to suit, creating a "listenability" that comes at the price of severe loss of information at high frequencies, which may be preferable, but does nothing for the idea of a wide band system or signal, nor does it improve the listener's ability to distinguish between the great and the merely good performance or interpretation.

While I owned Audio Innovations (sold out 1991) I spent years in denial and despite all the arguments in favor of the commercial considerations of what my company required I heard nothing from CD that encouraged much enthusiasm and since I prize my long term credibility more than just making money and as long as my favorite music was available on LP either new or second hand, I had no need for CD until the early 1990's when a lot of interesting material (mainly historical piano recordings previously unavailable) suddenly appeared on CD-only releases.
I had already spent a lot of time looking at the subject of digital to analog conversion, without achieving any really substantial sonic improvements against the better converters already available, my approach was to conformist, as it turned out, as it accepted too much of the existing dogma and therefore too closely followed the already beaten track.

In 1990 I decided to test the use of an interface transformer between the converter chip and the analog filter, primarily in the belief that a better interface between the D-A converter chips output should yield sonic improvements but also because I felt that separating the digital and analog circuits ground planes ought to yield some improvements.

Early experiments showed promise, but the matching impedance and associated analogue filter configuration were more critical than first assumed, after two years later we finally got it right and Audio Note launched it's first digital product, the DAC3 D-to-A converter with patents awarded in the UK, the USA, Germany, Australia and elsewhere.
Since then we have progressed with greatly refined components quality (DAC3 Signature), even more high quality components plus a power supply with a valve rectifier (the DAC4), and finally the best output stage and ultimate component quality (the DAC4 Signature), and whilst all of these measures achieved even better sound quality than the original DAC3 offered, the improved versions did nothing to dent the original product's price/quality relationship to competing converters, after 6 years on the market it is no mean achievement for a digital product to stay at the top of the performance spectrum in its price range in a market where model life generally is measured in months rather than years.

The more I studied the fundamental equations that all digital theory is based on, the more convinced I became that the sync functions used in the digital filtering must have a far more damaging effect on the signal, than is generally accepted (or even considered).

The basis for my idea is that there has to be a price to pay in all attempts to improve, "correct" or manipulate the signal, regardless whether it is done in the digital or the analog domain, and I have always thought that the digital filters with their oversampling, re-clocking, noise shaping, jitter reduction and whatever else are no different in their fundamental properties to the corrective feedback systems employed in the analog domain, in that they also try to "stop" or reverse time, so their deteriorating effect on the sound must be similar.

In early 1995 work started on the no digital filter - 1 x oversampling D to A converter and when Andy Grove joined me in 1996, his contribution to the idea was a first prototype within weeks of joining, a great credit to his talent and ability.

Although the first version had a fair bit of the sampling frequency breaking through, even with this interference it was obvious to everyone that the sound had something fundamentally "right", it was freer, had more presence, immediacy, delicacy and contrast than any digital product I had ever heard, there was obviously more good information in the digital data stream than previously thought, and it was clear that this converter had very serious sonic potential, so we persevered getting the interface transformer and filtering right, and here we are, nearly three years later introducing the finished product, the DAC5 Direct Line D/A Processor with 1 x oversampling and no digital filtering, re-clocking, noise shaping, jitter reduction or other such signal correction or manipulation.

Having listened to the final version of the DAC5 with its no-oversampling D to A conversion for nearly a year, I can say for the first time since my earliest experience with digital audio in late 1983 that digital has more to offer than I had ever imagined, because for the first time there is genuine contrasting quality between recordings with the DAC5, a fact which combined with an incredible sense of hall ambience, where instruments have greater presence, solidity and texture and a far more defined spatial position (provided this is what how it was recorded). An orchestra now has an organic quality where the musicians appear more like real people actually playing in real space, rather than as cardboard images in a sound deadened studio, the reproduction of stringed instruments has the sound and feel of real wood rather than the usual artificial and plasticky presentation of digital.

It may sound absurd, but the greatest beneficiaries of this vast improvement in the sound of my CD's are my big collection of historical recordings of piano music, the distinct differences in style, touch, tempo, tone, intonation and sound of each of the great pianists from Sergei Rachmaninov to Joseph Levinne, and from Simon Barere to David Saperton is a true revelation, which has greatly contributed to my appreciation of the interpretative skill, dedication and pure musicianship of these great artists.

When all is said and done, however and despite the DAC 5's great and almost analog qualities I still find my AN-TT Three Reference turntable with AN-1s/AN-Vz arm and IoGold cartridge excels with the best recordings, but now it is at least a contest between the two formats rather than a race between a Ferrari and a man wearing a pair of worn shoes!

The DAC 5 uses the Analog Devices AD1862NJ chip with as little in the signal path between it and the input chip as possible, the analog filtering has been done in such a way that the carrier frequency is inaudible, although it will show up on the oscilloscope in abundance (another example of the hard to grasp reality of measuring and its correlation to sonic reality)! We have experimented extensively with different filter configurations to find the one that passes an amount of breakthrough that does not disturb the ear without affecting the quality of sound more than necessary.

The DAC 5 has facility for 96KHz DVD technology, as well as the conventional 44.1 and 48KHz, it has high B C-core output transformers, with a 600Ohm balanced output using a professional Lemo connector (we can provide the silver cables with the Lemo plug for this) as well as a standard unbalanced RCA output.

There will be no patent applications or copy rights filed on this revolutionary idea, because that would limit its wider use by other manufacturers, to the detriment of the reproduction of music, instead we are offering this concept to you all, and this includes any of our competitors, all we ask is that you remember who thought of it and executed it first.

The DAC 5 is not cheap at £ 18,500.00, its component, power supply and transformer quality is far too expensive and elaborate for that, but go and give it a listen anyway, even if it is out of your price range, because the improvement it represents is nothing short of a digital revolution and you can rest assured that we shall move this advance in technology down in price as quickly as possible, so after 6 years most of our DAC-range (from the DAC3 upwards) will be upgraded to 1 x oversampling and 96KHz technology, to take us through at least another 6 years, which is in line with our stated aim to do our homework thoroughly and properly and only release products that have longevity built in.

Peter Qvortrup
September 1998


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Sonic.beaver



Posts : 2112
Join date : 2009-09-18

PostSubject: Re: Tuning a New World of Computer Audio Playback   Fri Feb 12, 2016 9:26 am

Greetings Zonees

The borrowed Audio Note 0.1x DAC has been running in Sonic’s system for six days now.  As I listen to the musick two things occur to Sonic:

1.      the performance of the ASUS laptop with the Audio Note 0.1x DAC proves the viability of computer music playback and that such playback can exceed the performance of CD players (this is not a new discovery – Hiend001 has found this to be so before me)

2.      Sonic needs to looks at ways to tune the computer front end. For now I cannot touch the innards of the 0.1x DAC as it is borrowed – of course if I buy the Audio Note more things can be done.

Right now the Audio Note 0.1x DAC sits directly on the Brazilian Pine board via its standard rubber feet, and the ASUS sits on the wooden stool directly too.

Let’s see where we can start.

The good news is the innards of the Audio Note 0.1x DAC are simple – one transformer (not too heavy) and a large PCB which has reasonable spacing between the components. Well designed, not crammed.



(source: www.hifi.com.sg)

There are cable ties round wire bundles and the large capacitors which can be cut, rubber feet to remove, screws to crack although given that it sits next to the opened up phono stage, I would be reluctant to run the AN 0.1x with the metal lid removed given that phono stages run with 50 to 60dB gain in the bass.

The power cable can be changed from the heavy AN-supplied IEC wire to Michael Green’s T1,  the DAC can be supported on AAB1x1 deep bell cones or machine wound Harmonic Springs from Michael Green, two cones or springs on the heavier transformer side and one under the PCB side. Sonic could also try Low Tone Redwood blocks to support the DAC. Something like this:



The laptop can be supported on three Harmonic Springs or three Harmonic Feet atop the wooden stool.

Sonic is connecting the computer to the DAC using the freebie USB cable that came with the AUNE 24/192 DAC (a device that proved to be less of a success) and all the descriptions Zonees have read so far are with this cable in use.  Sonic tested a USB by a High-End manufacturer who makes cables, a popular mini DAC and an anti-jitter device on a thumb drive, this affordable emerald green cable with gold-plated connectors gave a more vivid and exciting sound as a first impression, but in an evening of listening to familiar recordings, the vivid sound was a artifact in my system and to my ears and the bass had lost its rich warmth, becoming instead fast and tight. There was a "designed-in sound" that stayed with every FLAC file I played.  It got tiring quickly so I went back to the AUNE freebie. Then all returned to normal in about 15 minutes of music play (maybe up to an hour).

Now this makes a point that cabling even carrying 001000101010s in the digital domain have “different sounds” though I cannot explain why.

Sonic also learned from my friend the Network Expert who guided the set up of this system that I should always take the musick signal from the laptop from the same USB port rather than switch around. He gave me an explanation why but Sonic did not understand it.

Finally, Sonic is experimenting to see if there are differences in sound between the ASUS laptop on battery power or mains power.  There is a difference though I need to listen more before describing it and making a choice.  Right now it appears that using mains power might sound better (like Heind001 does). On battery power the sounds is a bit deader.  Sonic would like to hear Heind001’s views on this.

And Sonic is told that fresh stocks of the AUNE X1s 32/384 DAC have arrived.  You can guess what Sonic is thinking of doing next…..

Sonic
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Sonic.beaver



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PostSubject: Re: Tuning a New World of Computer Audio Playback   Sat Feb 13, 2016 8:32 am

Hello Hiend001 and Zonees  cheers

Sonic bought an AUNE X2s 32 bit/384 khz DSD DAC.

Set it up like this:



Downloading the driver was not simple but neither was it too difficult – the instructions of China-made AUNE could be a lot clearer on this aspect of the operation. Sonic means it isn’t much of an instruction manual that just tells you how to plug the thing into the mains and switch it on. There was nothing on downloading the driver and without that, the DAC simply will not work unless your laptop/PC already has XMOS installed.

Happily Sonic had help because after downloading the XMOS driver there was still the need to make XMOS the default driver for playback which didn’t happen automatically. Then the Foobar2000 needed to have its preferences set the way Hiend001 described with his screenshots.

With all this done, taking about 2 hours including head-scratching time, music started playing.

For anything cold and out of the box, Sonic never expects much and the sound, while showing promise, was shut down, bassy, dark and muddy sounding.

As the hours of music play went by the sound opened up and treble extension improved.  The balance became right.  Sonic can see why Hiend001 recommends this DAC so highly and why he liked it so much that he did not return to the Magnavox.

Tuning will start after the 24 hours operating point (we are now at about 7 hours point) with the usual starter actions:

a.RCA jacks inserted just enough to make contact and rotated for tuning

b.some form of mechanical grounding like using AAB1x1 deep bell cones, or machine wound Harmonic Springs under the AUNE

c.change the mains plug from a UK three pin to a Hubbell so it connects to the power strip without an adaptor

The balance between treble, mid and bass is very good – and the AUNE and the Audio Note 0.1x DAC driven by the ASUS laptop using Foobar2000 playing FLAC rips of Sonic’s CDs show how newly heard weight and character in bass points to the extent the Sony Blu ray player was choking off the bass which also explains why the bass from the analog LP playback system was better, more characterful if not ultimately extended, than digital.

Start the Tuning
After this there will be the opening up of the unit and taking the circuit boards out of the heavy aluminum casing, see pages 16 and 17 of Hiend001’s thread for pictures.  Will Sonic go as far as Hiend001 did with his top tuned AUNE X2s which he also top tuned? I might not do this given the risk of RFI and EMI from the digital circuitry getting into the phono system but Sonic should admit I would like to make an attempt knowing how powerful this path of Tuning is.

This is a promising start  Very Happy

Sonic
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tmsorosk



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PostSubject: Re: Tuning a New World of Computer Audio Playback   Sun Feb 14, 2016 8:28 am

Sweet set-up.
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PostSubject: Re: Tuning a New World of Computer Audio Playback   Mon Feb 15, 2016 8:05 am


Thank you, tmsorosk cheers

This is an enlightening time for Sonic Very Happy

I am letting the AUNE X1S settle before getting into Tuning so the only tuning Sonic did over the weekend was very basic – changed the UK 3-pin mains plug to a US standard plug so it fitted the power strip without needing an adaptor. Then I removed the four plastic (rubbery) feet stuck to the bottom of the casing, stood the AUNE X1S on three deep bell AAB1x1 (two front, 1 rear), and adjusted RCA jacks so they just made sufficient contact.

During this time Sonic also replaced the aging stylus of my Ortofon 2M Blue. I am just under the 1,000 hour mark specified by Ortofon as the useful life of the stylus so it is time for a new one. Listening to the new stylus sounding fresh tells me that while the old one had some way to go in terms of margin this change had to be done sooner rather later.

Now this means I can compare a fresh stylus and properly set up record player with playback of FLAC files through a dedicated laptop and a cracking good DAC – and know what? The sound from both sources is now striking in their similarity to each other in several and in good ways – while each is keeping their respective strengths eg: vinyl for its musical emotional connection, digital for its lower distortion and freedom from noise. Now in my system both are sounding equally “valid” with neither a second best.

Sonic

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PostSubject: Re: Tuning a New World of Computer Audio Playback   Wed Feb 17, 2016 8:38 am


Greetings Zonees

In the midst of enjoying lots of musick both analog and digital, Sonic is trying a few things:

a. the AUNE X1S has three switchable filter positions – 1. Fast roll-off linear phase (default) 2. Slow roll-off 3. Minimum phase.

This excellent and affordable DAC unfortunately comes with a poor instruction guide not up to the quality of the DAC device itself. Yes, there are instructions how to change filter setting (hold down the selector button for 4 seconds until the pilot light goes from green to red and let it cycle to the setting you want) but no discussion or tests on what the settings mean or do. Sonic is testing the filter settings and appears to be finding one seemingly better and one seemingly worse than the already very good default setting which is No.1 Fast roll-off linear phase.

b. I am using the same USB jack on my ASUS laptop to output music as my Network Expert advised me (which Sonic discussed on this thread earlier).

c. Sonic been testing too if the system sounds better if the ASUS is running off battery or mains. Earlier Sonic remarked with just battery the sound was very slightly deader. Now as I listen to the ASUS laptop and the AUNE 32/384 DSD 128 DAC, the difference is tiny and less than the variation between recordings. However more time Sonic spends playing FLAC files, I run off battery which appears to be better.

Will get into some Tunes of the AUNE X1S in Sonic’s next post.

I been finding the sound so good from my computer digital music replay system (and the turntable) that Sonic been listening to musick file after file, LP after LP…..and for a few weeks I have not even wanted once to tune anything in the room. Sonic has never been such an attentive listener Very Happy

Sonic
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PostSubject: Re: Tuning a New World of Computer Audio Playback   Fri Feb 19, 2016 8:38 am

Greetings Michael and Zonees

It has been nearly a week of using the AUNE X1S 32/384 DSD 128 DAC yet the unit has been powered up a lot and subject to settling in.  Some tuning has been applied to good effect:

a.      there are now three AAB1x1 deep bell cones under the DAC (2 front, 1 rear) and Sonic placed MW 2.5” x 2.5” x ¼” squares under the points of the cones – a deepening of the harmonics and a warming up of the sound was observed.



b.      from this picture, Zonees will notice that the volume knob has been removed.  Sonic opened up the DAC and had a look inside.  The power supply cables that were twisted in Hiend001’s AUNE X1S 32/384 now are untwisted in my version of the device. All screws including the torx screws holding the rear plate to the connectors have been loosened. So given that Sonic plans not to run the AUNE X1S 32/384 DSD 128 DAC without its casing due to concerns about interference with the high-gain phono stage (getting higher if I switch to a low-output Moving Coil cartridge).  



c.      dressed the cables including the USB cable and ensured no cable is resting on the floor



I will next attempt some tuning of the grounding of the ASUS laptop by interfacing it to the wooden stool it rests on.

The options are here:



The options would be a. no support b. elastomer (the rubbery pucks) c. Harmonic Feet (small) from Michael Green  d. Machine wound Harmonic Spring from Michael Green

How Does the System Play Musick?

Very nicely, thank you.

By now the sound has become a lot better than my Sony blu ray player ever sounded. Sonic is certain that player thinned out the upper and low bass which led me to spend so much time tuning for more warmth and bass which is produced in good quantities by the computer + DAC combination.
   
The sound is very “sure footed” particularly in the bass with the line distinct and easy to follow while harmonically integrated with the whole of the musick. Voices and instruments are present and projecting in a way Sonic hears with my Rega P5, Rega RB700 and Ortofon 2M Blue cartridge but not with Sony S380 CD/SACD player. More so Sonic can hear clearly words and inflexions of Muddy Waters singing Mannish Boy (from Hard Again)…..never enjoyed the records by Muddy and Johnny Winter & Co this much….wish Sonic had the LPs….never mind, this is excellent! Must credit Heind001 for pointing the way to computer storage and playback.

On the matter whether battery power or mains to the ASUS laptop sounds is curious – battery appears better but this is dependent on the battery’s charge state – full sounds odd, while 3/4-charged all the way down to under ¼-charged appears good, yet it appears overall quality might be better off the mains. Very curious – Sonic wonders if my guide Hiend001 has any comments?

Given how satisfying the sound has become, Sonic is considering a test where the AUNE 32/384 DSD 128 circuit board will be separated from its rather heavy alloy casing and placed on Low Tone Redwood blocks to see how it sounds. I suspect the results will be good given what Hiend001 achieved. For Sonic RFI/EMI intrusion into the phono stage is a concern.  So the thing to do is test and see what the result will be.

Sonic
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tmsorosk



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PostSubject: Re: Tuning a New World of Computer Audio Playback   Fri Feb 19, 2016 10:28 am

Sonic.beaver wrote:

Greetings Michael and Zonees



By now the sound has become a lot better than my Sony blu ray player ever sounded. Sonic is certain that player thinned out the upper and low bass which led me to spend so much time tuning for more warmth and bass which is produced in good quantities by the computer + DAC combination.
   


Sonic
   



Hello Sonic

Glad to hear it's working out.

I know what you mean about the player " thinning-out ". I've found most of those types of players to be thin sounding and quite unacceptable on many sonic parameters compared to a quality player.

It's taken many years to get my digital playback to sound on-par with my bigger tables ( S.M.E. 30/12 ) etc, different but sonically equal. I've found the right power conditioning for digital and totally separate from the analog equipment, all the way back to the breaker box was one key of paramount importance in getting things right.
When I first heard that analog warmth from a digital source I new I was on the right track.

Tim





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PostSubject: Re: Tuning a New World of Computer Audio Playback   Sat Feb 20, 2016 9:18 am


Greetings tmsorosk Very Happy

Thanks for corroborating my experience with the inexpensive Blu-ray player. The thinness in the bass led to a sound which Sonic could listen to but was critical of as “digital” given this thinness was never heard on vinyl.

More than that, this “thinness” may have led Sonic to give up tuning/adjusting the Janis W-1 subwoofer systems in earlier attempts. You and other Zonees will know how many times I have tried adding a subwoofer to my system.

Previously, the thinness (I did not know it was caused by the CD player) made me raise the Janis W-1 subwoofer’s cutoff to fill in the bass and mid bass, however when Sonic got that frequency band right, the lower bass was over boosted and I got an artificially heavy sound.

Now with my Computer Audio set up, the bass frequency response is right and so a small adjustment to the subwoofer cutoff level and the Janis W-1 is stably integrated into the system and room.

The other good thing is the AUNE 32/384 DSD 128 is beginning to show the same ease in the sound which the Audio Note AN 0.1x DAC has. Though the two are different in terms of spectral balance.

What do you use for mains conditioning for your digital system? Given the care you take to separate the digital and analog sides of you system, do you switch off your digital gear when listening to analog? Have you tried experimenting with USB cables or tried to deal with dirty 5V running in USB lines?

Sonic
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tmsorosk



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PostSubject: Re: Tuning a New World of Computer Audio Playback   Sat Feb 20, 2016 10:15 am

Sonic.beaver wrote:

Greetings tmsorosk  Very Happy



What do you use for mains conditioning for your digital system? Given the care you take to separate the digital and analog sides of you system, do you switch off your digital gear when listening to analog? Have you tried experimenting with USB cables or tried to deal with dirty 5V running in USB lines?

Sonic      

Howdy

On my main system I use a Panamax conditioner for analog and Shunyata for all things digital, both conditioners are run back to the breaker box on separate 20amp-12 gauge circuits with isolated grounds. No need to turn anything off.
Have only done minimal tests with USB cables, so won't comment for now.

Tim
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PostSubject: Re: Tuning a New World of Computer Audio Playback   Sun Feb 21, 2016 10:19 am

Thanks tmsorosk for helping with my questions.

Sonic first heard computer audio a little more than year ago through a very expensive system made by a company who hails from a land to the northern reaches of the British Isles.  The speakers (multiple cones in a very rigid cabinet) alone cost as much or more than the equipment Sonic uses.  On top of that the NAS system was their top of line device with excellent ease of use via an iPad.

The sound did not live up to expectation – the treble was muffled and inner details in the tracks obscured.  Sonic expected more but was told by an audiophile familiar with these devices that if I wanted computer audio I have to reset my expectations downwards and get used to that sound.

Since then Sonic wrote off computer audio and the couple of attempts to revisit this form of storage and playback in the intervening time only reinforced Sonic’s earlier disappointment. Nevertheless Sonic is a realist and I know that computer storage and playback in some form is in our future.

Then I read what Heind001 recently achieved with the ASUS, Foobar2000, XMOS 2.23 and the AUNE 32/384 with the Tune of course.  This time, with this set it works nicely. What Sonic got so far had made me move my Sony BDP S380 to the tuning closet and I think a little tuning of the computer, the linkage and the AUNE 32/384 will give me the system that Sonic hears in dreams.

Anyway FLAC files are not only what Sonic been listening to.  Here are 3 great records I listened to this weekend.



Sonic
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PostSubject: Re: Tuning a New World of Computer Audio Playback   Mon Feb 22, 2016 9:59 am


Greetings tmsorosk and Zonees

A couple of things Sonic forgot to add yesterday:

a. while this thread is called “Tuning a New World of Computer Audio” it won’t be just about Computer Audio. While Sonic likes the ins and outs of technology, Sonic looks at technology as a means to an end, rather than something that exists for its own sake. So this thread will dive into Computer Playback as my digital music delivery front-end yet there will be lots of discussion on tuning the room and the analog playback gear – yes, there is still the 78 rpm and SP playback to integrate in.

Right now, I got more than half of my CDs ripped (OK, Sonic employed help) and when all that is done, the CDs, their shelves and storage will exit the room to another part of my dwelling. This means Sonic can address something I discussed with Mr Green – further emptying of the Bookcases and dealing with the presence of a very heavy CD cabinet at the rear wall. In experiments Sonic has discovered that tuning in the area behind the Bookcase Wall affects the sound of the whole room. I used to think that anything behind the Bookcase Wall did not matter till I tried some things Michael advised with a FS-PZC and some FS-DTs and found out that that space is critical too.

b. Sonic would also be exploring things like the power supply for the computer and the DAC as well as the USB 2.0 cable and the EQ function of the Foobar2000. While my Network Expert who has been very helpful in getting me set up with computer audio (Thank You if you are reading this my friend), I want to explore the view held among engineers like him that once a signal is in the form of 00100010001111s and moved about as 00100010001111s nothing like wire affect it. My test with two USB cables and hearing the difference told me about possibilities. Sonic wants to examine this in context of the Tune while being wary of over-engineered and over-priced things designed to tease the “High-End Audiophile” Mind and pocket. Of course, the Network Expert and the engineering fraternity may be right that all this is an illusion. We shall see.

Sonic
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PostSubject: Re: Tuning a New World of Computer Audio Playback   Wed Feb 24, 2016 9:29 am

Greetings Zonees

After using the ASUS computer and the AUNE 32/384 DAC as my only digital source for more than 10 days with lots of settling time, Sonic has observed that as settling takes place, the sound now shifts down in tonality ie: getting bassier and moving towards muddy.  This is different from earlier experiences where there was tendency to shift up over time.

Is this significant, Michael? Might this allow the reintroduction of Space Cones….

Sonic also found out more about the digital filter settings of the AUNE of which there are three – Fast Roll Off, Slow Roll Off and Minimum Phase. These are three modes of digital Finite Impulse Filters where frequency response and rate of roll off is traded off against impulse performance through the filter.

Initial testing by Sonic shows Fast Roll Off to be brighter, Slow Roll Off somewhat duller and Minimal Phase somewhere in middle with good reproduction of fine musical detail.

For a technical paper on the FIR filter types and their frequency/time response (not related to the AUNE implementation), see this:

Ayre_MP_White_Paper.pdf

Ayre is pleased to announce the results of an intensive research program into the audible performance of various digital filters (including “non-oversampling” filterless designs). Extensive listening tests have shown that our new custom DSP-based “Minimum Phase” filters provide a significant leap forward in both musical naturalness and ease of listening. All of our current digital products use these filters, and upgrades are also available for all Ayre disc players still in production.

The Evolution of the Digital Filter To illustrate the performance differences between various digital filters, included are graphs of their two key parameters—their frequency response and their transient (impulse) response. These graphs allow us to trace the evolution of the digital filter, clearly showing the changes that have led to improved sound quality.

The Ayre MP Series
In the beginning, there was the common linear-phase, “brickwall” digital filter. This type of digital filter is used in 99+% of all modern digital equipment, for both recording and playback, including the “Measure” position of the original Ayre disc players.

On paper, it looks nearly perfect. There is no phase shift, so it is called a “Linear Phase” filter. However, a filter can only achieve a “Linear Phase” response by introducing pre-ringing. This means that before every single musical transient, there is a “pre-echo”. In nature, there is no such thing as a “pre-echo”. All events must be “causal” in the real world—the cause must precede the effect.

A sharp, “brickwall” filter like this typically introduces about 20 cycles of pre-ringing and 20 cycles of post-ringing. It is very unnatural sounding, as the effect (pre-echo) precedes the cause (musical transient). This time-smear is interpreted by the ear-brain as both a lack of image precision in the soundstage, and also a subtle smearing of the musical sounds together.

2
“Brickwall” Digital Filter, -6 dB  at 22,050 Hz, ~20 Cycles of Both Pre- and Post-Ringing
Linear-Phase “Measure” Frequency Response
Frequency (Hz)
Amplitude (dB)
Amplitude
Time
Linear-Phase “Measure” Impulse Response
20         200                 2K                        20K              44.1K 69
48
27
06
84
63
42
21
0
Improving the Transient Response The first approach to solving the problems of a conventional digital filter was to use a filter with less ringing, often known as a “slow roll-off” filter. This type of filter was used in the “Listen” position of the original Ayre disc players. By reducing the “sharpness” of the “knee” in the filter’s frequency response, the filter’s transient response is vastly improved. Now there is only about one cycle of pre- and post-ringing.
The penalty (remember, there is no such thing as a free lunch—only intelligent tradeoffs) is that there is more “leakage” (aliasing) of high frequencies above 22,050 Hz back in to the audio band. Still, this only affects very high frequencies and the levels are low enough not to cause audible problems.

This “slow roll-off” filter reduces the time smear by a factor of ~20x compared to conventional digital filters. The net result is a much more musically natural sound, as the ear-brain is very sensitive to time-related distortions. This filter provides an outstanding compromise between frequency response and transient response, and for ten years was the mainstay of Ayre’s digital audio filters.

A natural extension to this idea is to eliminate the digital filter altogether. In theory this provides the best transient response possible from a digital playback system. There are certain audible advantages to this approach, but they are highly system-dependent and come at the expense of two separate problems.
The first is a loss of high frequencies starting at -0.75 dB at 20 kHz and reaching -3.2 dB at 20 kHz. The second is that the aliased “image” frequencies are injected into the audio signal, creating non-harmonically related distortion that increases in level as the frequency increases, reaching over 50% at 20 kHz unless additional analog filtering is employed.

Careful listening tests revealed that these drawbacks outweighed the gains in improved transient response, especially given the CD format limitation with its 44.2 kHz sample rate. We therefore continued examining different approaches to digital filtering.
2
“Slow Roll-Off” Digital Filter, -6 dB  at 22,050 Hz, ~2 Cycle of Both Pre- and Post-Ringing
Linear-Phase “Listen” Frequency Response
Frequency (Hz)
Amplitude (dB)
Amplitude
Time
Linear-Phase “Listen” Impulse Response
20         200                 2K                        20K              44.1K 69
48
27
06
84
63
42
21
0
Eliminating the Pre-Echo In Peter Craven’s 2004 AES paper, he proposed that the playback DAC should include a digital filter that had a corner frequency below the half-sample rate of 22,050 Hz. This would filter out any ringing (pre- and post-) that was introduced during the recording process and thereafter embedded on the disc itself. He named this an “apodizing” filter.

It is a mathematical law of any filter, digital or analog, that the steeper the frequency cutoff, the more ringing it will have. In an attempt to avoid the problems of this ringing, Craven proposed using a “Minimum Phase” filter instead of the conventional “Linear Phase” filter. While this means that the phase response now varies, especially at high frequencies, there is no longer any pre-ringing. Furthermore all pre-ringing from the recording process has been filtered out, and the new playback filter only has post-ringing.

Now a giant step forward has been taken in the musical naturalness of digital audio reproduction. The unnatural pre-echoes have been completely eliminated. All of the filter’s ringing occurs after the musical transient. This is just the way that sounds occur in nature. Every sound made in the real world will have post-echoes after the original sound, so the ear-brain system more easily accepts these post-echoes from the digital filter as natural.
Note that the post-ringing of a “Minimum Phase” filter is greater than that of a “Linear Phase” filter with the same frequency response. The energy that had been contained in the pre-ringing of the “Linear Phase” filter has simply been delayed until after the transient. (Remember—there are no free lunches.) But redistributing this same total energy leads to significant gains in musical realism.

This type of digital filter is not available in off-the-shelf chips. Instead, it must be implemented in custom DSP filters. In the case of the new Ayre MP (Minimum Phase) disc players, we use sophisticated FPGAs (Field Programmable Gate Arrays) to create the desired custom filter, and the chip is easily reprogrammable should future improvements be made. This filter type is used in the “Measure” position of the new Ayre MP disc players.
3
“Apodizing” Digital Filter, -200+ dB  at 22,050 Hz, No Pre-Ringing, ~20 Cycles of Post-Ringing
Minimum-Phase “Measure” Frequency Response
Frequency (Hz)
Amplitude (dB)
Amplitude
Time
Minimum-Phase “Measure” Impulse Response
20         200                 2K                        20K              44.1K 69
48
27
06
84
63
42
21
0
The Best of Both Worlds While the “Apodizing” filter proposed by Craven solves many of the problems with digital filters, careful listening tests conducted at Ayre showed that the multiple cycles of post-ringing still created an artificial brightness and an overall confusion to the sound. We therefore sought to combine the best aspects of Craven’s minimum-phase digital filter proposal with a slower roll-off that reduced the overall amount of ringing.
4
The resulting filter has no pre-echoes, and only about one cycle of post-ringing. This filter is implemented in the “Listen” position of the new Ayre MP disc players. The result is simply the most musically natural digital playback available today.

In addition to the radical improvements provided by the digital algorithms themselves, several man-months were spent conducting thorough listening tests to optimize all other aspects of the filters. The powerful customprogrammed FPGAs used in the MP series allow performance far beyond that available from off-the-shelf solutions. The mathematical calculations are conducted with 32-bit coefficients, using 64-bit accumulators to ensure the greatest degree of signal precision.

A 26x oversampling rate was determined to provide the highest level of musical realism. All of the filtering calculations are accomplished in a single pass through an FIR (Finite Impulse Response) filter. This is in contrast to conventional designs that employ a cascade of 2x FIR filters, thereby losing critical precision of the audio data as it is passed to each successive filter section. Finally, the dither algorithms for both the “Listen” and “Measure” filters were chosen on the basis of careful listening tests to provide the most realistic music reproduction possible.

The Ayre MP filter provides a significant step ahead in digital audio reproduction. The CX-7e    provides this advanced technology for CDs, while the C-5xe    universal disc player takes this to the limit of today’s recording technology at 292 kHz and 24 bits. In addition, this exclusive advance in digital audio reproduction is included in the Ayre QB-9 USB DAC, achieving the most natural and realistic sound available from computer-based audio systems



Sonic
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PostSubject: Re: Tuning a New World of Computer Audio Playback   Fri Feb 26, 2016 9:07 am

Greetings Michael, Heind001 and Zonees

Sonic did this to tune the AUNE 32/384 DAC and the sound changed, the soundstage width, image specificity and front-back positioning and perspective all improved.  The musicality of the digital side of Sonic’s system went up another notch  Very Happy



This is a leaf out of Hiend001’s tuning process with the AUNE. Notice in this later model that Sonic bought, the wires from the power switch to the PCB are not twisted.

Right now I am still experimenting with the AUNE filter settings – there is an emerging preference for Minimum Phase.  One of Sonic’s very liked CDs is a Harmonia Mundi CD of Andrew Manze playing Georg Philippe Telemann’s 12 Fantasias for Solo Violin.  Now on the CD player, the baroque gut-stringed violin sounds like it is recorded in an bathroom and the details of multiple-stopping and other playing technique my Maestro Manze is unclear if not smeared in the echoey sound.  Playing the FLAC file through the ASUS and AUNE, using the Minimum Phase filter setting, the ambience is spread coherently through the room and the techniques used to play these complex pieces are definite with no smearing.

Also playing jazz – Gene Ammons’ Boss Tenor (Prestige), the impact and rasp of Eugene “Jug” Ammons’ tenor sax is realistic and draws Sonic back to a live performance when I was facing the bell of a tenor sax from a few feet away and experienced the presence in every note and the “push/impact” in the leading edge of low notes. Again Sonic did not get this realism to the same extent with the standalone CD player.

Moreover, the switching between recordings, Sonic can hear how different recordings sound so different from each other, even track to track. Now it stands to reason that two recordings made in two studios with different mikes, recording equipment and such will have to sound different. In fact if the recordings were too alike, Sonic would be worried if the system resolution was so poor as to obscure the differences.

Will the next step be top tuning the AUNE?  I have to figure that one out and place the AUNE 32/384 DSD 128 in such a way that I can reach the power switch easily without knocking the Top Tune Canopy over.

From Sonic's experience the Top Tune method taught by Michael works good.  Just need to be careful and it is best for things that do not get touched a lot.

Yet what appears very immediate is the possibility of returning to some application of the Space Cones in Sonic’s room/system given that my system settles in the warm, dark direction rather than shifting up.

A question for Hiend001: which filter setting do you prefer and why  Question  

Michael – your views  Question

Sonic
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PostSubject: Re: Tuning a New World of Computer Audio Playback   Sun Feb 28, 2016 9:38 am

Greetings Zonees

Looks like the graphs in the Ayre pdf doc could not be uploaded.  If you want to see them, follow the link yet for now Sonic can give you summary what it is in them.

Graph 1: In the impulse response with the Linear Phase/fast Roll Out filter shows as much pre-echoes as there are residual oscillations after the impulse – a clearly abnormal effect as our Universe on macro scales is created to be causal in nature – the Cause happens first in time followed after by the effect (what happens on quantum scales is another matter).

Graph 2: with a Slow Roll Off filter there are still pre-echoes but less cycles on both the pre and post-impluse sides.  This is better yet not the whole solution.

Graph 3 and 4: with a Minimal Phase filter all the oscillations are after the impulse – which corresponds to our experience of the natural physical world.  

Sonic should say that I attached this document because the paper gives a clear description of Linear, Slow Roll Off and Minimal Phase filters. While Sonic respects Ayre as a reputable brand of well-engineered products, the inclusion of this document on Tuneland is not a sign of that Sonic has a view on this company’s products.

Right now I am listening to Chet Baker and Duke Jordan’s The Complete Concert at George’s.  This is Baker on trumpet, Jordan on piano and a bassist.  The sound of the FLAC file is excellent, the event is present and the bass is fuller and bigger than the blu-ray player from Sony ever gave me.  

Yes, Sonic has to say that Michael was right when he observed there were blockages in my system.  One big blockage was the Sony S380 blu-ray. It partially choked off the bass and the dynamics of the musick.  Sonic is finding that when I set the volume level at the start of some familiar recordings, the sound gets way too loud later….so this is a happy outcome for Sonic with this project where I have got 526 CD ripped. That's past half way and the ASUS' disk player appears to be holding out.

I noticed something when testing the Audio Note 0.1x DAC, the output level slide of the Foobar2000 1.3.39 affected the playback level at the speakers.  With the XMOS 2.23 driver for the AUNE 32/384 the slider does not have any effect on the volume output from the DAC to the rest of the system. Wonder what this means….?

Sonic
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PostSubject: Re: Tuning a New World of Computer Audio Playback   Tue Mar 01, 2016 10:29 am

Greetings Zonees

More findings and developments with Sonic’s system:

Sonic has one Harmonia Mundi CD of Vivaldi’s chamber concertos for bassoon, oboe, recorder, violin, cello and harpsichord (La Pastorella) which till now when played on my CD players and the Blu-ray player was fatiguing with a hard sound. I could not listen to the CD through to the end. Yet now I got the CD ripped, the FLAC file is pleasant and musical.  For the first time Sonic sat through the entire programme and enjoyed the music thoroughly.



Why should this be?  It could be there were peaks or high levels in this CD that caused overload in the blu ray player’s DAC which the Foobar2000 avoids by giving headroom by playing back at -15dB dBFS so the recording no longer shows the “hardness” distortion that is often with digital. Sonic has observed that during ripping that many CDs are at 99.5% of dBFS.  Might many of the criticisms raised against CDs be just a matter of overloaded DAC inputs?

Also did a clutch of tests on which support is best under the ASUS computer (see my post of Feb 19, 2016). To recap, the choices Sonic had are  a. direct placement on the mini-wooden bench  b. elastomer feet   c.  Harmonic Springs (machine wound) d. Harmonic Feet (small).

After near to a week of testing Sonic concludes that direct placement is pretty good and will work in the majority occasions.  However, the Harmonic Feet give better midrange clarity and image tightness yet there are some recordings that the Harmonic Feet make the mids a tad too forward.  The difference is small but noticeable in favour of Michael’s Harmonic Feet.

The Harmonic Spring was OK but the computer tended to slide about so let’s put safety first. The elastomer (rubbery material) gave a solid sound initially but darkened the inner details and sounded artificial after a while. Sonic will use Harmonic Feet or direct placement as the musick feels. This might be a form of dynamic tuning of the system to take in different recording characteristics.

Now the Tune Instinct is speaking again to Sonic – the placement of some of the acoustic treatments in the treatment of the room needs to be revised particularly at the front wall.

I’ll be getting to adjust the acoustic treatment in the room next.

Sonic
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PostSubject: Re: Tuning a New World of Computer Audio Playback   Wed Mar 02, 2016 4:26 am

Hi Sonic

Everything is analog Smile

Digital is a language (code), but analog is signal and sound.

I'm looking forward to my computer/dac system but this will not change my tuning and dialing in each recording. I say each recording as a choice in reference to how far I want to go.

During my last season of listening to several different CDP's I ended up coming to the same conclusion I have for the last couple of years. The Magnavox (that small window of players) is the winner when it comes to tuning and warmth, and because I have had so many of these units, I'm hearing the differences between each player.

I say this as an intro to the discussion on comparing the different sources. I would be surprised if I find the computer setup to take first place over all the other sources, much the same as I like some vinyl over CD and some tape over vinyl. My goal is to setup several source types and enjoy each for what they are.

I do have 3 DAC's sitting by though while we decide on source, either lap top or android or some other toy Smile

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PostSubject: Re: Tuning a New World of Computer Audio Playback   Sat Mar 05, 2016 11:00 am

Greetings Michael and Zonees  cheers

Good to hear from you again on this thread, Michael.

Yesterday, the ASUS’ CD drive/burner gave up the ghost after 625 rips.  Sonic knew this when I put a CD in the drive tray and started EAC which told me that no disk was detected.  This is about the same lifespan as Hiend001 who managed about 550 CDs before the CD drive stopped working.

A trip down to the store and a Samsung CD drive costing US$35 and we are back to ripping with about 200 to go at most.

Now to my adjusted room treatment tuning -- Sonic did this placement to good effect with the two DecoTunes formerly placed at the side walls ahead of the Magneplanar MG1.5QRs:

Here is the “Before”:



And “After”:



This is what went to the old locations to maintain the same amount of overall acoustic control in the room:



The result is a much sharper imaging in 3D terms, good width and the ability to hear details deep in the soundstage. Depth is seamless and balanced across the stage. I mean often systems show more depth at centre stage and less at the Left and Right edges of the soundstage.

Now to Michael’s point made in his Wednesday post.

In Sonic’s view the various formats/storage medium – CD, SACD, computer storage, Hi-res, MP3, vinyl records, analog tape, cassette and 8-track  Shocked - should be secondary to the objective of music.  While the compressed lossy systems (MP3) and convenience formats (cassette and 8-track) have traded off some quality for convenience, all the other major formats have their strengths and weaknesses.  Digital today is a far cry from what it sounded like in the early 1980s.  There are audiophiles who play the exclusivity card – eg: “I play 15 ips master tape copies, everything else is a sub-standard compromise” and so they turn up their noses at others. But this is the wrong spirit, a spirit of exclusivity that keeps creating categories that stratify things unnecessarily and keeps music lovers apart.  

On the other hand, the Tune is able to make wonderful music out of any format – in fact Michael could tune MP3 to the point listeners thought it was CDs. So while Sonic is enjoying the quality I am getting from the ASUS/AUNE front end, it is in comparison to the Sony BDP S380, this situation may be different if Michael had applied his skills and fully tuned the Sony.

For Sonic, I would go where the music is – if something I want to hear is available on LP, 78 or MP3, it doesn’t matter, first priority should be the musick and it can always be tuned to be better.

Digital and vinyl are different musical experiences for Sonic. Vinyl is about selecting a record from the shelves, the ritual of putting the recording on the player, cleaning the stylus, brushing the dust off the record, cueing the stylus and sitting back and listening while holding the record sleeve art in my hands and reading the liner notes.

Sonic
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