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 Vintage Stereo "Classic Audio"

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MGA

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PostSubject: Vintage Stereo "Classic Audio"   Sun Mar 29, 2015 6:05 pm




Vintage stereo, as new as it is old, plays not only a historic role in todays music but is often revisited to find lost treasures left on the cutting room floor. This thread is dedicated to vintage stereo and it's part in shaping our now.
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Sonic.beaver



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PostSubject: Re: Vintage Stereo "Classic Audio"   Fri Apr 03, 2015 11:38 am

Greetings Zonees

One of the renown classic speakers is the JBL Ranger Paragon.  It is a huge speaker about 9 ft wide with both channels in one complex cabinet. Picture below. 




Above is a diagram to give Zonees an idea of what’s inside.

Sonic went to a second-hand audio store where I saw this and got to hear it briefly powered by tube amplification. The music playing was stuff I am unaccustomed to so Sonic cannot give you a considered view on the sound.  But in the few minutes Sonic surmised that the Paragon does not have an “old’’, “classic” sound.  Even in the crowded store, uncertain set up and accompanying gear, it had a fast and clear sound.  There was something about the sound that was “right” but the programme being played limited my ability to tell anything for certain. But the thing that Sonic noticed quickly was the “ease” of the sound.

What I also learnt was this Paragon had been sold for US$30,000.  

Here is information on the great JBL Ranger Paragon from www.audioheritage.org:

No other loudspeaker developed by JBL has the mystique or desirability of the D44000 Paragon. It was a landmark product, based on a unique design principle, that remained in production longer than any other speaker system from JBL. It was introduced in 1957 and continued in JBL's line-up until 1983.

The Paragon is a stereo speaker system installed in a single cabinet. It is based on a diffusion principle developed by Richard Ranger as consultant to JBL. The midrange drivers fire towards a curved wood panel that reflect the sound waves to create a wide, spacious stereo image. The principle is explained above in Richard Rangers own words.

How Richard Ranger came to JBL is somewhat of a mystery. He was renowned for technical work in the movie and theater industry. It is believed that he was independently developing the diffusion principal for professional applications. It has been speculated that he was using JBL drivers in his experiments and that this was the connection that brought him to JBL. It is known that in 1958, he installed the first amplified sound system used in a Broadway theater and that this installation was based on the same Paragon diffusion concept using JBL drivers.

A little known fact is that the Paragon was originally envisaged as a center channel speaker to be flanked by separate left and right speakers that would be similar in configuration to the Hartsfield. This was related to research conducted in the 1930's by Bell Labs that purported the most stable stereo image was achieved with a center channel speaker. However the cost and space requirements for such a system would be prohibitive and the concept was revised to be a standalone stereo system.

The stunning industrial design for the Paragon was developed by Arnold Wolf. He was hired as a consultant to this project and later went on to become President of JBL in 1970. The Paragon was a very complicated system to construct. In the 1960's, JBL estimated that 112 man-hours were required to complete a single system. Much of this time was invested in cabinet finishing. Eight hours was spent sanding the entire enclosure after assembly. Then a single coat of oil was applied by hand and allowed to dry overnight. Two more coats of oil were applied the next day before six hours work was applied for final touch ups. Subsequent to this, yet another coat of oil was applied and hand rubbed. The Paragon was available in numerous finishes that included Teak, Rosewood, Birch, Mahogany, Walnut, Oak, Antique White and Ebony. In addition, special finishes could be ordered at higher costs such as piano lacquer.

The original configuration of the Paragon consisted of two 150-4C bass drivers mounted in separate, front-loaded horns. Two 375 compression drivers were mounted to H5038P-100 elliptical horns and each was aimed at one side of the curved panel. Two 075 ring radiators were mounted in the back of the cabinet and aimed at the center listening position. The drivers were crossed over at 500hz and 7000hz. At the same time that the home version of the Paragon was introduced, there was an industrial variant that was intended for built-in applications such as studio monitoring and stereo movie sound reproduction. However, there never was a great demand for this application and the industrial variant was soon dropped from the lineup.

The driver complement of the Paragon went through numerous changes over the years. The early 60's saw the 150-4C replaced by the newly developed LE15A. The option of ordering the Paragon as a powered system was also introduced at that time with the availability of the SE408S power amplifier installed in the cabinet. The powered option was removed by the 70's and the driver complement changed again 1979. In that year, JBL converted the magnetic structures of all of their bass drivers to utilize ferrite magnets instead of Alnico V. It resulted in the replacement of the LE15A with the ferrite LE15H. In addition, the 375 midrange driver was replaced with the Alnico 376 which used a new diamond pattern suspension for extended response. This configuration remained until the product's discontinuance in 1983.

Up until the system's discontinuance, there was a devoted manufacturing space set aside at the JBL plant just for the Paragon. At it's peak, Paragons were produced at the rate of five per week. By the 1980's, this rate had been reduced to one or two per month. No records were kept of total production, but it is thought that around 1000 systems were built over a period of approximately 25 years. To this day, it is arguably the most sought after vintage loudspeaker system ever made. Pristine examples can command over $20,000 in the collector's market.

It is interesting to note that there was no complete set of plans for the manufacture of the Paragon. Many of the construction procedures existed only in the minds of the builders. In most cases, it would not be possible to substitute cabinet parts from one Paragon into another since they were individually hand crafted for the system at hand. Plans were available in the 1960's for sale to home builders that dimensioned the the individual parts, but even these have subsequently become lost to JBL.

http://www.audioheritage.org/html/profiles/jbl/paragon.htm
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Sonic.beaver



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PostSubject: Re: Vintage Stereo "Classic Audio"   Sat May 23, 2015 8:49 am

Greetings Classic Audio Fans@Techno-Zone!

In the early issues of The Abso!ute Sound back in the 1970s (that is more than 40 years ago!) you will see that the reference system used by Harry Pearson, John W Cooledge and co was:

Turntable:  Sony TTS 3000 -- a servo-controlled belt drive TT that paved the way to Direct Drive

Tonearm:  SME 3009 II -- which was modified for even lower mass my cutting away parts of the headshell....rigidity was a later thought...so it could work better with the ADCs whose early models had such high compliance that the wrong antiskate or absence thereof could twist the cantilever in its mounting...

Cartridge: ADC XLM

Tape: Revox A77

Preamp:


  • Citation 11a


  • Audio Research SP-3 -- these were wonderful sounding for their day but technicolored by today's standards. Also the early SPs took some time to settle.  You switched them on and let them warm up for about 5 minutes before switching the Main Amp on. If you switched on the Main Amp too fast, you might get a thump that might damage the speakers. Today, we have much better B+ control for our tubed amps so this sort of thing never happens


Amplifier: Phase Linear 700

Loudspeakers:

  • Double Advents -- stacked atop each other tweeter to tweeter


  • Dayton-Wright Electrostatics -- these full-range 'stats had their elements sealed in a bag of Sulfur Hexaflouride, an excellent dielectric gas to prevent arcing but now known to be one of the most potent greenhouse gases known


  • Audio Research Magneplanars -- back then Magneplanars were distributed by Audio Research


  • Double KLH-9 electrostatics -- doubled up for more SPL and bass

Sonic[/list]


Last edited by Sonic.beaver on Sat May 23, 2015 9:04 am; edited 2 times in total (Reason for editing : formatting x3)
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PostSubject: Re: Vintage Stereo "Classic Audio"   Thu May 28, 2015 11:37 pm



Hopefully this is close enough for Sonic's list.

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PostSubject: Re: Vintage Stereo "Classic Audio"   Sat May 30, 2015 10:06 am

Thanks for sourcing the pictures Michael!

Zonees may wish to see this video of three pairs of the KLH-9 electrostatics:



https://www.youtube.com/watch?gl=SG&hl=en-GB&v=zSs2Dpzu0Sw
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Sonic.beaver



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PostSubject: Re: Vintage Stereo "Classic Audio"   Sun Jul 12, 2015 5:03 am

Hello, what's this?



Source: http://audiooyazi.exblog.jp/

Sonic
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PostSubject: Re: Vintage Stereo "Classic Audio"   Tue Jul 14, 2015 9:20 am


Sonic loves Japanese audio Very Happy The ingeniousness of the Japanese audiofan exceeds those found anywhere else in the world.

This picture puzzles Sonic. This audiofan has turned his tonearm into a 12 incher or something with the extension to the headshell. Notice that the arm base has been moved, the squat cylinder presumably covering where the tonearm pillar mounting hole was.

But look at the arc of the tonearm swing and see where the stylus winds up at the centre of the record. This arm as set up does not have overhang. It has underhang -- the stylus ends up on the side of the spindle closer to the tonearm.

If you set your arm this way and played a record with an elliptical or line contact stylus, you will get twisting and tangential forces that will damage the groove and the stylus. It seems a Stanton with conical stylus is being used here.

The only time an underhang set up can work is with a straight tonearm with no cartridge/stylus offset like some Japanese arms.

Here is a tonearm with an offset angle....what is the reason for this set up?

Sonic
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Sonic.beaver



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PostSubject: Re: Vintage Stereo "Classic Audio"   Sat Jul 25, 2015 10:34 am


Hello Zonees

Here is a July 2013 interview with Mark Levinson. Whatever your opinions about him and his products there are some things worth reading here:

http://www.hometheaterhifi.com/musician-and-vocalist-artist-interviews/musician-and-vocalist-artist-
interviews/mark-levinson-for-the-love-of-music-part-2.html

A sample of what’s in the interview:

Earlier this year, I had the privilege of interviewing Mark Levinson, one of the most influential men in the entire high-end audio industry. We spent hours discussing a wide range of topics—so many, in fact, that they could not be squeezed into a single article.

If you haven't yet read part 1, I encourage you to do so before moving on to part 2. Here, Levinson shares his thoughts on analog versus digital audio, the effect of cables on sound quality, 2-channel versus multichannel music, movie soundtracks, and the problems facing consumers shopping for audio gear.

Analog vs. Digital Audio

Naturally, I was interested in Levinson's take on analog versus digital audio. "For me, the first thing is the content. If the content is only available on SACD or CD or LP or download or wherever, that's what I'm going to listen to, because if I don't, I won't hear it at all. If it's a recording I want to listen to, I don't care what it's on, I want to listen to that particular piece of music.

"Every recording medium has its limitations. I've always liked analog tape, but it's very expensive and messy. The recorders are big and heavy, and you have to calibrate them with mechanical and electrical adjustments. It's very time consuming and requires a lot of test equipment. Plus, the tape stock varies and can be hard to get. It goes on and on."

What about digital?

"There are two kinds of digital audio. There's PCM (pulse-code modulation), which is used on CDs and DVD-Audio, and DSD (direct-stream digital), which is the basis of SACD (Super Audio Compact Disc). In terms of sound quality, PCM has always been a mixed bag; there have always been people who don't like it. Dr. John Diamond went further than anyone in understanding the problems of PCM, but the world didn't want to hear what he had to say." For more
on Diamond's findings, see www.drjohndiamond.com/digital.

"On the other hand, DSD was....."

Go read the rest of the interview at the Home Theater HiFi site.
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Sonic.beaver



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PostSubject: Re: Vintage Stereo "Classic Audio"   Sun Aug 09, 2015 8:38 am

One Japanese audiophile's approach to tonearm set up....how can this be bettered?



Source: http://www.gokudo.co.jp/index2.htm
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Sonic.beaver



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PostSubject: Re: Vintage Stereo "Classic Audio"   Sat Sep 05, 2015 10:51 am


Greetings Zonees

As Sonic experiments with my system to build pressure at the Bookcase Wall and de facto round my listening chair to strengthen the bass and girth which you can read about on my main thread, Sonic has been thinking about an observation of many wonderful British speakers.

The Quad ESL57s, the 63s and more recent models of their electrostatic panels were designed to sit directly on the floor or on short feet or stands. The top edge of the speakers are below listeners' ears when sitting on a chair/sofa of normal height when placed as the manufacturer advises and not using after-market stands.

Also the Spendor SP1/2 speakers are recommended by the manufacturer to be placed on 8 to 10 inch stands which for a listener on an average chair and of normal build meant the tweeters are again below ear level. Similarly the Harbeths that Sonic finds goodly and musical when placed on stands of a height approved by their maker. Even mini-monitors like the LS3/5As on 24 inch stands put the tweeters below the listener's ears.

Sonic notices that many British audio systems very often are listened to with the speakers low which give an effect like looking down on the performers as if we are sitting in the upper tiers of a concert hall. Perhaps this was the intention Shocked

Yet Sonic finds if the orchestra, quartet, ensemble images low like I am looking down on the performers something is odd. But the exploration of music with listeners I have met have taught Sonic much. Certainly I know listeners who Sonic has met who are very musically discerning and musically literate yet to whom soundstage means nothing.

And truth to tell Sonic has passed the point where realism means stereo -- in the case of many of the LPs Sonic loves, mono gives true realism and a kind of "stereo in the mind" and is truer in many respects.

Sonic


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PostSubject: Re: Vintage Stereo "Classic Audio"   Sun Sep 06, 2015 4:21 pm


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PostSubject: Re: Vintage Stereo "Classic Audio"   Sat Oct 03, 2015 9:24 am

Cartoonist/illustrator R Crumb is a sophisticated collector of vintage recordings with this mono system in his home in France.  The speaker is a Klipsch:



From Two Good Ears    
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PostSubject: Re: Vintage Stereo "Classic Audio"   Sun Oct 04, 2015 11:12 am

While Sonic figures what equipment Robert Crumb is using, I found this at  http://audiooyazi.exblog.jp/

Those Japanese audiophiles are ingenious but what on earth is this Question Question Question

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PostSubject: Re: Vintage Stereo "Classic Audio"   Wed Oct 07, 2015 10:34 am


Greetings Zonees

Sonic been pondering and meditating on this homebrew cartridge wondering what it could be. Then the enlightenment arrived. This is a homebrew Field Coil Phono Cartridge Idea Trust the ingenious Japanese DIYers to dare try developing something like this. Sonic recalls that Audio Note makes a Field Coil Cartridge commercially -- it costs the moon -- and it has six terminal pins, four for the signal R chn/R Ground/L chn/L Ground plus two more for the powered coil. Exactly as here. The google translation of some of the Japanese text on this site refer to an IM electromagnet. A homebrew Field Coil Phono Cartridge is probably what this is and the other versions of this thing built from other donor cartridges you see here. That's what this is Sonic surmises.

Sonic
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Sonic.beaver



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PostSubject: Re: Vintage Stereo "Classic Audio"   Thu Oct 08, 2015 8:33 am

Hello Zonees

Sonic meditated on this picture and realized I was wrong. This cannot be a homebrew/DIY field coil. The only form of cartridge I know that can be “field coiled” is a Moving Coil and this and the other cartridges on this site modded this way are not MCs. I think too that Japanese audiophiles won’t do this to any MC as they worship those things. So what might this be? It could be some sort of Induced Magnet design and the coil is where the signal is generated and the wires carry not voltage to energise the coil but to conduct signal out to the phono stage. This is a mono cartridge so only one coil. The positioning of the electromagnet pole piece is significant towards my new thought of what this might be – the early ADCs and Empires (Induced Magnet/Moving Iron) had a pole over the stylus assembly like this though there was no giant coil. I wonder what the weight of this thing is.

Sonic
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Sonic.beaver



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PostSubject: Re: Vintage Stereo "Classic Audio"   Sun Oct 11, 2015 10:39 am

Greetings Zonees

We may associate the French with the Notre Dame Cathedral, the Champs Elysee, the Eiffel Tower, cordon bleu cooking, Bordeaux Wine but what about the French expression of our noble preoccupation with musick and audio?

It is there!

Have a look - forums.melaudia.net/showthread.php?tid=2952



Yes, we should look a little more at French audio.  Sonic is looking.

Sonic
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Sonic.beaver



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PostSubject: Re: Vintage Stereo "Classic Audio"   Wed Oct 14, 2015 10:31 am

Here are the loudspeakers of that marvelous French system:



Sonic
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Sonic.beaver



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PostSubject: Re: Vintage Stereo "Classic Audio"   Sat Oct 17, 2015 9:22 am

SALUTE TO JOE BUSSARD

Few people have devoted as much of their life to records as Joe Bussard has. Born in 1936 in Frederick, Maryland, he started playing records on his parents’ phonograph and by the end of World War II, he had the collecting bug. During the 1950s, 60s, and 70s, he led thousands of record expeditions through the mid-Atlantic region and the South, looking for 78s of jazz, blues, ethnic and down-home/bluegrass music. These expeditions went well beyond the typical digger routes of mining thrift stores or finding out-of-the way record stores. For Joe, record collecting has always meant driving into the backwoods, parking your car, and walking door-to-door asking the locals if they had any records in the house and, if so, would they be willing to sell them.

http://www.djforums.com/forums/showthread.php?17504-Joe-Bussard-crate-digger-supreme



http://farm3.static.flickr.com/2426/3915870047_566a54eb50_b.jpg
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Sonic.beaver



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PostSubject: Re: Vintage Stereo "Classic Audio"   Sun Oct 18, 2015 9:13 am

Look at this from Japan….http://www.gokudo.co.jp/index2.htm



Notice the notes stuck between the Tuner and Preamp?  That is the EQ table for different record brands before the standardization of RIAA.

And this:



The red roller is a wonderfully ingenious stylus cleaner. Sonic would like install one on my Rega turntable. Apparently this wonderfully ingenious stylus cleaner from Decca is a very sought after item by collectors on eBay.

Yummy….

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Sonic.beaver



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PostSubject: Re: Vintage Stereo "Classic Audio"   Sun Dec 20, 2015 11:46 am

Greetings Zonees

Today we think of phono cartridges as motors working on the Moving Magnet, Moving Coil, Moving Iron, Variable Reluctance principles.  There are things like Optical and Field Coil too but the main motor systems available are MM, MC, and MI largely.  There was also the Piezo system/Ceramic  that was looked down upon and faded into history.  They came with a "flip stylus" (often sapphire which didn't last long) that allowed you to play LPs and 78s. Often these Piezo cartridges were associated with the turntables that came in the Console Stereos popular in the 1960s.  

These Piezos/Ceramic cartrdiges had a response that gave automatic approximation to an RIAA playback curve so you plugged a turntable equipped with a Piezo/Ceramic pick-up head into an Aux input of your amp not the Phono one.

Sonic wondered what sort of frequency response these gave compared to the best of today's MM and MCs.  Sonic found this article on the Sonotone piezo cartridges on www.roger-russell.com/

Have a look:

Sonotone Phonograph Cartridge History
By Roger Russell

Perhaps the best known Sonotone hi-fi products were the ceramic crystal and phonograph cartridges sold in the late 40's to the early 60's. Many were supplied by the hundreds of thousands to OEM manufacturers, such as Motorola, Voice of Music, Wurlitzer and Symphonic.

Here is a picture taken in 1948 for the Sonotone Corporation byWain & Barsch, Inc., 37 West 57th Street, New York 19, N.Y. (Peter J. McGovern). The information on the back of the picture is as follows:

“Elmsford, N.Y.  July 1948 --- Anthony Bozzuto spends his days at the Sonotone plant here spinning platters. But unlike radio’s disc jockies his job is listening, not entertaining. Tony tests phonograph pickups made of a ceramic material as part of an inspection to assure quality output. The gadget which goes into the phonograph arm and converts electrical impulses into electrical energy, is called “Titone,” first-man made substance with piezo-electrical qualities. It was developed by the Sonotone Corporation, hearing aid manufacturers. Crystals heretofore were widely used in pickups. Tony plays popular records as well as a special platter with sounds of varying frequencies.”



1948 Press photo
Dolores Poorman making a listening test for phono cartridges in Quality control at the Sonotone Corporation.

Sonotone advertised the Titone ceramic cartridge in the January and March 1954 issues of Service, a technical journal of the television and radio trade.

“No other cartridge gives all these features!”

“No preamplifier or equalizer needed--Unaffected by moisture or temperature--Wide frequency range--Outstanding response--High Sensitivity--Low distortion--High compliance--No hum pickup--Superior tracking ability--Wide adaptability--Proper groove fit--Only needle rotates--Simple to replace.

Titone Ceramic cartridges are unaffected by temperature and humidity. They do not deteriorate on the shelf or in equipment, as crystals do. The ceramic principle is an original discovery and development of the Sonotone laboratories. The demand for Titone is growing daily. More and more quality-conscious manufacturers are specifying Titone for original equipment. The same high quality is available to you in every Titone ceramic pickup cartridge.”

Perhaps the most popular stereo cartridge beginning in the late 1950s was the 8TA stereo cartridge (right). Sonotone also made a wide variety of low cost replacement cartridges and needle assemblies. The replacement cartridge catalog contained 5700 cross-references which are too long to reproduce on this page.



In 1959, I started my first job as an engineer at Sonotone. I began in phonograph cartridges, but the following year I had to take a leave of absence for a six-month tour of duty in the Signal Corps. Sonotone had a history of supplying the military with various equipments. With the recommendation of Raul Ferillo at Sonotone, I was able to be assigned to the Audio Development Section of the US Amy Signal Research and Development Laboratory at Ft. Monmouth, New Jersey. When I returned to Sonotone, there was a position available for me to work in microphone research and development and I took that. In addition to designing microphones, part of my time was also spent on developing new Sonotone loudspeaker products. I stayed with Sonotone for eight years.

In 1959, Norman Dieter, Jr. was the chief engineer in charge of cartridges and tape heads. He reported to Harry Pearson, director of research. After Norman left in the mid sixties, Sam Shatavsky, who was the engineer responsible for tape head development, replaced him. Tape heads were discontinued about 1965.
Phil Kantrowitz



was a senior design engineer. He started at Sonotone in 1954. Phil wrote several papers for the Audio Engineering Society while he was employed at Sonotone. His first paper was titled Reproduction distortion--It's Measurement and Influence on Stereo Phonograph Cartridge Design and was presented at the Twelfth Annual Convention of The AES in October, 1960. I advised and assisted him in preparing his second paper; Distortion Measurements of High-Frequency Loudspeakers presented at the Thirteenth Annual Convention in October, 1961. In the next few years Phil presented even more papers titled: High frequency Stylus-Groove Relationships In Phonograph Cartridge Transducers (1962), Mechanical Impedance Measurements at the Stylus of Stereo Phonograph Cartridge Transducers, Electrical Loading Networks for Stereo Phonograph Cartridge Transducers, and Transducer Development for the Artificial Heart or Heart Assist Devices (1967). Phil was also a member of the SMPTE and IEEE.

Cartridges were tested in a room with controlled temperature and humidity. Ballantine AC voltmeters were used throughout the lab as they had a linear dB scale. Test records such as Cook 10LP and Westrex were used. Sound Apparatus chart recorders were used, including a special dual channel recorder with doublewide paper. Response and separation could be displayed at the same time.

In 1962, the CBS STR 100 test record became available. It was adapted for use with the General Radio 1521-A Graphic level recorder. The January-February 1962 issue of the General Radio Experimenter contained an article titled "Automatic Measurement of Phonograph Reproducers" by B.B. Bauer. An automatic start circuit was described using the 1000 cycle tone at the beginning of each glide to automatically start the chart recorder. Arnold Schwartz and A. Gust at CBS developed this. It became a standard test at Sonotone.

The heart of the ceramic phono cartridge is a piezoelectric material, called lead-zirconium titanate. This material has a unique electro-mechanical property. A mechanical stress, such as bending, produces a voltage from one side to the other. The behavior is very much like the earlier Rochelle salt crystal used in crystal cartridges. The ceramic material, however, has much greater stability to both temperature and humidity.

Ceramic material is very linear. The peak output voltage is almost unlimited. Since no coils are involved in the construction, the ceramic cartridge is much less susceptible to hum pickup. Some early magnetic cartridges had other problems. The Fairchild 220, for example, had such a strong external magnetic field, it was strongly attracted to a steel turntable and could literally crush the needle assembly when lowered on a record.

Another unique feature of the ceramic cartridge is that it's response is amplitude based instead of velocity based like magnetic cartridges. This means that phono equalization is not required. The cartridge, when electrically loaded with 1 megohm or more, will produce a flat response with a typical output voltage of 0.4v. It does not require the extra stages of amplification. In low-cost phonographs, the cartridge is used to drive the output tube directly. An example is the 50EH5, that can deliver 1.4 watts when used in this manner.

Although Sonotone made many monophonic cartridges, the 3T cartridge is perhaps the best. The ceramic element material is in the shape of a bar. At the rear of the cartridge, one end of the ceramic element is sandwiched tightly between high durometer rubber pads. A gold plated brass connector is inserted between the ceramic element and the rubber, one on each side. The brass pieces extended out of the rear of the cartridge to form the cartridge connections. The other end of the ceramic element is glued to a brass piece that has a U shaped groove protruding from the front. The entire cavity around the ceramic element is injected with silicone damping compound. The stylus armature rests in the U shaped groove. Sideways motion of the stylus can then bend the ceramic bar and generate an output voltage. The stylus armature can be axially rotated by 180 degrees with no effect on performance. A 1 mil stylus can be mounted on one side for LP records and a 3 mil stylus can be mounted on the other for 78's. A simple turnover lever is all that is needed for the change. This also makes removal of the stylus assembly very easy for replacement. The needle assemblies are made with a variety of stylus sizes as well as in diamond and sapphire.

Stereo records required a new approach. A resolver in the form of a pantograph is found to work very well and is patented. It becomes the basis for the Sonotone stereo cartridges. The ceramic bar elements are mounted at 90 degrees to each other and 45 degrees to the vertical. The mounting methods for the ceramic elements include high durometer rubber pads, brass connectors, and silicone damping compound similar to the monophonic cartridges.

A flexible butyl rubber link is used between the lever arm and the needle shank. It is called the SONO-FLEX needle. This makes the stylus/armature relatively indestructible to accidents, like dropping the arm on the record, or dragging the stylus across the record. It can even flex in a 360 degree orbit and spring back in place.

The response of the ceramic cartridges, like the 9T are somewhat limited to 10 or 12kHz. At the time, however, disc cutters were struggling to get response on the records above 9kHz.



As popularity of magnetic cartridges increased, many preamplifiers no longer provide a ceramic cartridge input. To maintain sales of ceramic cartridges, the output of the ceramic cartridge is changed to look like a magnetic cartridge. The output is reduced and shaped by a passive RC network. In 1960, the first version is incorporated into a pair of small plug-in adapters for stereo. Later marketing gave them the name of Velocitone. The adapters are less than 2" long and can be plugged into a normal magnetic phono input and the turntable output can be plugged into the adapters. The inherent advantage of linearity and insensitivity to hum pickup can still be retained. The 9T ceramic stereo cartridge with Velocitone adapters is reviewed in the September 1961 issue of Electronics World.

The 9T Mark IV cartridge is a significant improvement over the 9T. Response goes out to 20kHz, although somewhat peaked at 15kHz. Separation also decreases at 15 kHz indicating resonance is occurring at that frequency. The Mark IV cartridge with Velocitone adapters is reviewed in the May 1965 issue of High Fidelity.

The 100T cartridge is a further improvement over the Mark IV. Response is much smoother, although the 15kHz peak remains. The 100T cartridge with Velocitone adapters is reviewed in the November 1966 issue of High Fidelity magazine.
The 100T Mark V cartridge maintains response out to 20kHz, although somewhat peaked at 15kHz. Separation again decreases at 15kHz indicating resonance is still at that frequency.



Typical network for the Sonotone 9T series cartridges



This board makes it easier to identify all of the Sonotone cartridges
Whatever became of the Sonotone cartridges?

About 1965, Sonotone was bought by the Servel Corporation and was later owned by the Clevite Corporation.

In April of 1969, the Astatic Corporation, a long time competitor, purchased the Audio Products line of Sonotone from the Clevite Corporation. This included the phonograph cartridge, needle and microphone products, production tools, dies and inventory of finished and semi-finished materials, as well as domestic patent rights. A year earlier, Astatic had purchased the Euphonics Corporation, also makers of ceramic cartridges and needles. Sonotone continued with hearing aids and accessories, as well as rechargeable nickel cadmium batteries.

No known significant advancements or innovations for the ceramic cartridges were made at Astatic. In 1987 they were bought by CTI Audio, Inc., Conneaut, OH. The Astatic products are now only microphones and accessories.

The ceramic cartridge lived on, however, and continued to evolve at Micro-Acoustics. Both Arnold Schwartz and Norman Dieter, both formerly of Sonotone, had much experience with design and manufacture of these cartridges. Improved versions continued. See the section on Micro-Acoustics.


Last edited by Michael Green on Sun Dec 20, 2015 1:48 pm; edited 9 times in total (Reason for editing : Added more information)
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Sonic.beaver



Posts : 2049
Join date : 2009-09-18

PostSubject: Re: Vintage Stereo "Classic Audio"   Wed Jan 27, 2016 10:04 am

Hello Zonees

Here is another one of those cartridges with the double-ended stylus mounts -- the GE/RPX:

Source: http://audiooyazi.exblog.jp/



Sonic
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