Sonotone Phonograph Cartridge History

By Roger Russell

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Perhaps the best known Sonotone hi-fi products were the ceramic crystal and phonograph cartridges . In the late 50's and early 60's, these were sold by the hundreds of thousands to OEM manufacturers, such as Motorola, Voice of Music, Wurlitzer and Symphonic.

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 was the 8TA (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. When I returned, I was assigned to work in microphones. In addition to designing microphones, part of my time was 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, would produce a flat response with a typical output voltage of 0.4v. It did not require the extra stages of amplification. In low-cost phonographs, the cartridge was used to drive the output tube directly. An example is the 50EH5, that could deliver 1.4 watts when used in this manner.

Although Sonotone made many monophonic cartridges, the 3T cartridge was perhaps the best. The ceramic element material was in the shape of a bar. At the rear of the cartridge, one end of the ceramic element was sandwiched tightly between high durometer rubber pads. A gold plated brass connector was 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 was glued to a brass piece that had a U shaped groove protruding from the front. The entire cavity around the ceramic element was injected with silicone damping compound. The stylus armature rested in the U shaped groove. Sideways motion of the stylus could then bend the ceramic bar and generate an output voltage. The stylus armature could be axially rotated by 180 degrees with no effect on performance. A 1 mil stylus could be mounted on one side for LP records and a 3 mil stylus could be mounted on the other for 78's. A simple turnover lever was all that was needed for the change. This also made removal of the stylus assembly very easy for replacement. The needle assemblies were 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 was found to work very well and was patented. It became the basis for the Sonotone stereo cartridges. The ceramic bar elements were mounted at 90 degrees to each other and 45 degrees to the vertical. The mounting methods for the ceramic elements included high durometer rubber pads, brass connectors, and silicone damping compound similar to the monophonic cartridges.

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

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

Later versions of the stereo cartridges incorporated small plug-in Velocitone adapters. As many preamplifiers no longer included a ceramic cartridge input, the output of the ceramic cartridge was reduced and shaped by passive RC networks to be like a magnetic cartridge. The Velocitone adapters, less than 2" long, could be plugged into the normal magnetic phono input and the turntable output plugged into the Velocitone adapters. The inherent advantage of linearity and insensitivity to hum pickup could still be retained. The 9T ceramic stereo cartridge with Velocitone adapters was reviewed in the September 1961 issue of Electronics World.

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

The 100T cartridge was a further improvement over the Mark IV. Response was much smoother, although the 15kHz peak remained. The 100T cartridge with Velocitone adapters was reviewed in the November 1966 issue of High Fidelity magazine.

The 100T Mark V cartridge maintained response out to 20kHz, although somewhat peaked at 15kHz. Separation again decreased at 15kHz indicating resonance was still at that frequency.

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, formerly of Sonotone, had much experience with design and manufacture of these catridges. Improved versions continued. See the section on Micro-Acoustics.

 

 

 Sonotone Cartridges

• 1966 suggested list prices.

1P Mono single needle ceramic. Response 20-20kHz (flat to 12kHz). Output 1.0v. Compliance 1.0. Load 1-5 megohms. Tracking force 8-10 grams. [1P-1S Price $6.10]

2TA Mono turnover ceramic. Response 20-20kHz (flat to 12kHz). Output 1.0v. Compliance 2.0. Load 2-3 megohms. Tracking force 6 grams. [2TA-S Price $7.40]

3T Mono turnover ceramic. Response 20-20kHz (flat to 15kHz). Output 0.5v. Compliance 2. Load 2-3 megohms. Tracking force 4-6 grams. [3T-S Price $9.75]

8TA Stereo/Mono turnover ceramic. Response 20-20kHz (within 2.5dB, 20-15kHz). Output 0.3v. Compliance 3.0. Separation 20dB. Load 1-5 megohms. Tracking force 4.6 grams for changers, 3-5 grams for professional arms. [8TA4-SD Price $14.50]

9TA F Stereo/Mono turnover ceramic. Response 20-20kHz (within 0.5dB, 20-6kHz, within 2dB 20-17kHz). Output 0.4v. Compliance 5.5. Separation 30dB. Load 1-5 megohms. Tracking force 3-5 grams for changers, 2-4 grams for professional arms. Universal terminal plug. Sono-Flex needle. [9TAF-SD Price $14.60]

9TAFHC Stereo/Mono turnover ceramic. Response 20-20kHz (within 0.5dB, 20-6kHz, within 2dB 20-17kHz). Output 0.2v. Compliance 15. Separation 30dB. Load 1-5 megohms. Tracking force 3-4 grams for changers, 1.5-3 grams for professional arms. Universal terminal plug. Sono-Flex needle. [9TAFHC-SD Price $15.15]

9T Velocitone Mark IV Stereo/Mono turnover ceramic. Response 20-20kHz (within 0.5dB, 20-6kHz, within 2dB 20-17kHz). Output 7mv. Compliance 15. Separation 30dB. Load 47k to 100k. Tracking force 3-4 grams for changers, 1.5-3 grams for professional arms. Universal terminal plug. Sono-Flex needle. Includes matched Velocitone equalizers. [9TAFHC-SDV Price $23.15]

10T2 Stereo/Mono turnover ceramic. Response within 2.5dB 20-15kHz. Output 0.5v. Compliance 1.5. Separation 18dB. Load 1-5 megohms. Tracking force 5-7 grams. Universal terminal plug. "Fuse clip" mounting. [10T2-SD Price $12.20]

12THA Stereo crystal. Response to 10kHz within 2dB. Output 2.5v. Compliance 1.4. Separation 20dB. Load 1/2 to 5 meg. Tracking force 9-11 grams. [12THR-S Price $6.95]

12TLA Stereo crystal. Response to 10kHz within 2dB. Output 1.5v. Compliance 2.2. Separation 23dB. Load 1/2 to 5 meg. Tracking force 6-8 grams.

14T Mono turnover crystal. Response: entire audio hearing range. Output 3.6v. Compliance 1.0. Tracking force 10 grams. [14T-S Price $3.15]

15T Mono turnover crystal. Response: entire audio hearing range. Output 3.6v. Compliance 1.0. Tracking force 10 grams. Boss mounted. [15T-S Price $3.15]

16TAF Stereo/Mono turnover ceramic. Response 20-12kHz (within 1.0dB, 20-10kHz). Output .65v. Compliance 2.4. Separation 25dB. Load 2 megohms. Tracking force 5-7 grams for changers, 4-6 grams for professional arms. Universal terminal plug. Sono-Flex needle. [16TAF-SD Price $11.65]

18TA Stereo/Mono turnover ceramic. Response 20-12kHz (within 1.0dB, 20-10kHz). Output 1.0v. Compliance 1.5. Separation 25dB. Load 2 megohms. Tracking force 5-7 grams for changers, 4-6 grams for professional arms. Universal terminal plug. Sono-Flex needle. [18TA-SD Price $11.00]

19T2 Stereo turnover crystal. Response: entire audio hearing range. Output 2.0v. Compliance 1.0. Separation 12dB. Tracking force 8 grams. Boss mounted. [19T2-S Price $4.40]

20T1 Stereo turnover crystal. Response: entire audio hearing range. Output 1.0v. Compliance 1.0. Separation 12dB. Tracking force 8 grams. [20T1-S Price $4.40]

20T2 Stereo turnover crystal. Response: entire audio hearing range. Output 2.0v. Compliance 1.0. Separation 12dB. Tracking force 8 grams. [20T2-S Price $4.40]

21T-S

21TR Stereo turnover ceramic. Response: entire audio hearing range. Output 0.6v. Compliance 5.5. Separation 21dB. Tracking force 4-7 grams. Retractable mounting bracket. Sono-Flex needle. [21TR-SD Price $12.20]

22T Stereo turnover ceramic. Response: entire audio hearing range. Output 0.3v. Compliance 10. Separation 24dB. Tracking force 2-4 grams. Snap-in mounting bracket. Sono-Flex needle. [22T-SD Price $12.20]

23T Stereo turnover ceramic. Response: entire audio hearing range. Output 0.4v. Compliance 10. Separation 26dB. Tracking force 2-4 grams. Snap-in mounting bracket. [23T-SD Price $13.10]

24T Stereo turnover ceramic. Response: smooth over entire audio hearing range. Output 0.25v. Compliance 4. Separation 21dB. Tracking force 4-7 grams. Capicitance 4500pf. Sono-Flex needle. For transistor applications. [24T-SD Price $13.95]

25T Stereo turnover ceramic. Micro-Ceramic light weight. Response: smooth over entire audio hearing range. Output 0.2v. Compliance 15. Separation 24dB. Tracking force 1-3 grams. [25T-MB-SD Price $14.70]

26T Stereo turnover ceramic. Micro-Ceramic light weight. Response: smooth over entire audio hearing range. Output 0.5v. Compliance 65. Separation 21dB. Tracking force 3-6 grams. [26T-MB-SD Price $14.70]

27T Stereo turnover ceramic. Micro-Ceramic light weight. Response: smooth over entire audio hearing range. Output 0.18v. Compliance 5. Separation 22dB. Tracking force 3-6 grams. Capacitance 4100pf. For transistor applications. [27T-MB-SD Price $15.45]

28T Stereo turnover ceramic. Micro-Ceramic light weight. Response: smooth over entire audio hearing range. Output 0.35v. Compliance 9. Separation 22dB. Tracking force 2-4 grams. [28T-MB-SD Price $14.70]

35T Stereo turnover ceramic. Response: smooth over entire audio hearing range. Output 1.0v. Compliance 1.5. Separation 20dB. Tracking force 6-8 grams. Capicitance 850pf. Sono-Flex needle. For transistor applications. [35T-SD Price $15.45]

100T Velocitone Mark V. [100T-DEV Price $39.50]

Slim Tonearm Complete With Cartridge

T14T-S Complete with 14T series mono crystal cartridge. Price $4.40

T20T1-S Complete with 20T1 series stereo cartridge. Price $5.70

T20T2-S Complete with 20T2 series stereo cartridge. Price $5.70

Ceramic and Stereophonic needles

N-8TA-S [0.7-mil sapphire and 3-mil sapphire] Price $3.15

N-8TA-S77 [dual 0.7-mil sapphire] Price $3.15

N-8TA-SD [0.7-mil sapphire and 3-mil diamond] Price $4.40

10T2-SLB [0.7-mil sapphire and 3-mil sapphire]

10T2-S77LB [dual 0.7-mil sapphire]

10T2-SDLB [0.7-mil diamond and 3-mil sapphire]

10T2-SD77LB [0.7-mil diamond and 0.7-mil sapphire]

N-12THR-S [0.7-mil diamond and 3-mil sapphire] Price $3.15

N-12THR-S77 [dual 0.7-mil sapphire] Price $3.15

N-12TLA-S [0.7-mil diamond and 3-mil sapphire] Price $3.15

N-12TLA-S77 [dual 0.7-mil sapphire] Price $3.15

N-14T-7D [0.7-mil diamond] Price $2.00

N-18T-S [0.7-mil sapphire and 3-mil sapphire] Price $3.15

N-18T-S77 [dual 0.7-mil sapphire] Price $3.15

N-18T-SD [0.7-mil diamond and 3-mil sapphire] Price $4.40

N-19T2-7S [0.7-mil sapphire] Price $.75

N-19T2-3S [3-mil sapphire] Price $.75

N-20T-7S [0.7-mil sapphire] Price $.75

N-20T-3S [3-mil sapphire] Price $.75

N-20T-7D [0.7-mil diamond] Price $2.00

N-21T-S [0.7-mil sapphire and 3-mil sapphire] Price $3.15

N-21T-S77 [dual 0.7-mil sapphire] Price $3.15

N-21T-SD [0.7-mil diamond and 3-mil sapphire] Price $4.40

N-25T-S [0.7-mil sapphire and 3-mil sapphire] Price $3.15

N-25T-S77 [dual 0.7-mil sapphire] Price $3.15

N-25T-SD [0.7-mil diamond and 3-mil sapphire] Price $4.40

N-25T-S(S) [0.7-mil sapphire and 3-mil sapphire] Price $3.15

N-25T-SD(S) [0.7-mil diamond and 3-mil sapphire] Price $4.40

N-26T-S [0.7-mil sapphire and 3-mil sapphire] Price $3.15

N-26T-S77 [dual 0.7-mil sapphire] Price $3.15

N-26T-SD [0.7-mil diamond and 3-mil sapphire] Price $4.40

N-26T-S(S) [0.7-mil sapphire and 3-mil sapphire] Price $3.15

N-26T-SD(S) [0.7-mil diamond and 3-mil sapphire] Price $4.40

N-27T-S [0.7-mil sapphire and 3-mil sapphire] Price $3.15

N-27T-S77 [dual 0.7-mil sapphire] Price $3.15

N-27T-SD [0.7-mil diamond and 3-mil sapphire] Price $4.40

N-27T-S(S) [0.7-mil sapphire and 3-mil sapphire] Price $3.15

N-27T-SD(S) [0.7-mil diamond and 3-mil sapphire] Price $4.40

N-28T-S [0.7-mil sapphire and 3-mil sapphire] Price $3.15

N-28T-S77 [dual 0.7-mil sapphire] Price $3.15

N-28T-SD [0.7-mil diamond and 3-mil sapphire] Price $4.40

N-28T-S(S) [0.7-mil sapphire and 3-mil sapphire] Price $3.15

N-28T-SD(S) [0.7-mil diamond and 3-mil sapphire] Price $4.40

*N-9916F-S [0.7-mil sapphire and 3-mil sapphire] Price $3.50

*N-9916F-S77 [dual 0.7-mil sapphire] Price $3.50

*N-9916F-SD [0.7-mil diamond and 3-mil sapphire] Price $4.75

*N-9916F-D77 [dual 0.7-mil diamond] Price $6.00

N-9916HC-S [0.7-mil sapphire and 3-mil sapphire] Price $3.80

N-9916HC-S77 [dual 0.7-mil sapphire] Price $3.80

N-9916HC-SD [0.7-mil diamond and 3-mil sapphire] Price $5.05

N-9916HC-D77 [dual 0.7-mil diamond] Price $6.30

N-100T-7D [0.7-mil diamond] Price $4.50

N-100T-5D [0.7-mil diamond] Price $5.50

N-100T-ED [elliptical 0.2x0.8 diamond] Price $8.50

N-35T-S [0.7-mil sapphire and 3-mil sapphire]

N-35T-S77 [dual 0.7-mil sapphire]

N-35T-SD [0.7-mil diamond and 3-mil sapphire]

*Sono-Flex needle. New & improved high compliance universal needle for 9T, 9TA, 9TAF, 9TV, 9TAV, 9TAFV, 16T, 16TA, 16TAF, 916T, 916TA and 916TAF series.

Note: (S) after model number indicates short turnover needle arm for slim tonearms and LB (less bracket) cartridge replacement.

Crystal and Monophonic Needles

N-1P-1S [1-mil sapphire for 1P cartridge] Price $2.85

N-1P-2S [2-mil sapphire for 1P cartridge] Price $2.85

N-1P-3S [3-mil sapphire for 1P cartridge] Price $2.85

N-1P-1D [1-mil diamond for 1P cartridge] Price $4.10

N-1P-3D [3-mil diamond for 1P cartridge] Price $4.10

N-2T-S [1-mil sapphire and 3-mil sapphire for 2T cartridge

N-2T-SD [1-mil diamond and 3-mil sapphire for 2T cartridge

N-2TA-S [0.7-mil sapphire and 3-mil sapphire for 2T cartridge Price $3.15

N-2TA-SD [0.7-mil diamond and 3-mil sapphire for 2TA cartridge Price $4.40

N-3P-1S [1-mil sapphire for 3P cartridge] Price $2.85

N-3P-3S [3-mil sapphire for 3P cartridge] Price $2.85

N-3P-1D [1-mil diamond for 1P cartridge] Price $4.10

N-3P-3D [3-mil diamond for 1P cartridge]

N-3T-S [1-mil sapphire and 3-mil sapphire for 3T cartridge Price $3.15

N-3T-SD [1-mil diamond and 3-mil sapphire for 3TA cartridge Price $4.40

N-14-TH-3S [0.3-mil sapphire] Price $.75

N-14-TH-1S [0.1-mil sapphire] Price $.75

N-15T-3S [3-mil sapphire] Price $.75

N-15T-1S [1-mil sapphire] Price $.75
N-19T2-3S [0.3-mil sapphire] Price $.75