MANUFACTURER'S SPECIFICATIONS:
Voltage Output at 1 kHz/cm/sec: 0.8mV ±2 dB (4 mV at 5 cm/see).
Compliance: 50 cm/dyne x 10^-6.
Vertical Tracking Angle: 20° nominal.
Channel Balance: ±2 dB.
Nominal Channel Separation: 30 dB at 1 kHz; 20 dB over the range 20 Hz to 20 kHz using JVC TRS-1005.
Recommended Load Impedance per Channel: 47 kilohms resistance in parallel with no more than 400 pF. How ever, when intended for use with CD-4 type records (Blue Label Stylus only), capacitance should not exceed 250 pF.
Total Cartridge Weight: 5.5 grams.
Tracking Force Range: 1 to 1.5 grams.
Inductance: 150 mH/channel nominal.
Resistance: 300 ohms/channel nominal.
Price: $154.00.
Replacement Stylus: $81.50.
With the introduction of the Blue Label Gold Series II, SONUS has moved to further refine their excellent line of phono cartridges, based on their state-of-the-art technology.
The SONUS Gold Series II contains an efficient magnetic structure that permits the use of a moving system of extremely low effective and total mass. The stylus tip is positioned on the same axis as the armature, so that little or none of the stylus motion is lost in rotation or by the generation of rotational resonances. The stylus pivot is located at the dynamic center of rotation of the moving system. It is made from material having nearly optimum elastometric properties, resulting in a highly compliant and very linear stylus suspension. Like previous SONUS cartridges, this series also has an extremely high compliance, which is specified as 50 x 10^-6 cm/dyne. The recommended tracking force is from 1.0 to 1.5 grams. Because of the very low inductance of the cartridge coils, the cartridge is less sensitive than usual to load capacitance and resistance. When mounting the cartridge, the manufacturer recommends that the arm should be adjusted so that the mounting surface of the cartridge is parallel to the record during playback.
The SONUS Gold Series II cartridge is available in three models, determined by their stylus type, but all using a common cartridge body. The Blue Label (top of the line) is fitted with a stylus of modified line contact that is suitable for the reproduction of stereo as well as discrete quadraphonic (CD-4, UD-4) records. The Red Label stylus is bi-radial (elliptical), and the Green Label stylus is spherical. Our review is restricted to the Blue Label stylus and cartridge.
Measurements
The SONUS Gold Series II Blue Label phono cartridge was mounted on an ADC LMG-1 magnesium headshell, whose total weight (including screws and nuts) was 8.5 grams, probably making it the lightest headshell currently available. The mounted cartridge was used with our reference tonearm, an Audio-Technica AT-1009, mounted on a Technics SP-10 turntable. The cartridge was loaded with 47 kilohms in parallel with 200 pF capacitance for all measurements, except for those measurements above 20 kHz when the total capacitance in parallel with the 100-kilohm load was less than 100 pF. All measurements were made at a tracking force of 1.5 grams. During the test period, the average temperature was 70° F (21.11° C) and the relative humidity 65 percent ± 3 percent.
Fig. 1--Frequency response and separation from the CBS STR-170 test disc.
Fig. 2--Frequency response and separation from the JVC TRS-1005 test record.
Fig. 3--Response to 1-kHz square wave.
Frequency response, using the Columbia STR-170 test record, is flat within 0.5 dB from 40 Hz to 12 kHz, then starts to slowly rise to +1 dB at 15 kHz and +2 dB at 20 kHz.
Separation is 26 dB at 1 kHz, 17.5 dB at 10 kHz, 17 dB at 15 kHz, and 15 dB at 20 kHz. Inasmuch as this cartridge can also be used to play discrete quadraphonic records, we measured the frequency response up to 50 kHz using the JVC TRS-1005 test record. The high frequency response with this test record was +2.5 dB at 30 kHz, +4.5 dB at 40 kHz, and +6 dB at 50 kHz. Separation at these three frequencies was 14 dB, 16.5 dB, and 13.5 dB, respectively.
The response to. a 1-kHz square wave shows a very large overshoot followed by ringing that decayed moderately quickly, with a stylus resonance at about 34 kHz. This type of square-wave response is common with cartridges capable of playing CD-4 records. The cartridge-arm low-frequency resonance was at 7 Hz and of 9 dB amplitude.
We understand that straight out of the box the vertical stylus angle is 30°, which is much greater than usual. Apparently, the cartridge is deliberately made this way (due to high compliance?) because after a brief period of use the stylus settled down to about 24°. We wonder how much of this settling is due to movement in the butyl elastomer of the suspension pivot block and if, perhaps after a year of use, the angle might go further down?
The following test records were used in making the reported measurements: Micro-Acoustics TT-2002; Shure TTR-103, TTR-109, TTR-110, and TTR-115; Columbia STR-170, STR-100, STR-112 and SQT-1100; JVC TRS-1005; Deutsches HiFi No. 2, and the Nippon Columbia Audio Technical Record (PCM) XL-7004.
Wt. 5.5 gm; d.c. res. 332.5 ohms; inductance 131.3 mH; opt. tracking force 1.5 gm; opt. anti-skating force 2.5 gm; output 0.72 mV/cm/sec; IM distortion (4:1) +9 dB lateral, 200/4000 2.7 percent, +6 dB vertical, 200/4000 5.8 percent; crosstalk (using Shure TTR-109)-28 dB; channel balance ± 1.1 dB; trackability: high freq. (10.8 kHz pulsed) 24 cm/sec, mid-freq. (1000 + 1500 Hz, lat. cut) 31.5 cm/sec, low freq. (400 + 400U Hz, lat. cut) 24 cm/sec; Deutsches HiFi No. 2 300-Hz test band was tracked cleanly to 95 microns (0.0095 cm), lateral at 17.9 cm/sec at +10.33 dB and 43.1 microns (0.00431 cm), vertical at 8.12 cm/sec at +3.64 dB. These latter measurements are extremely good and very few cartridges can track all the 300-Hz bands on this test record.
The SONUS Gold Series II Blue Label cartridge was able to play all the tracking and transient ability bands of the Micro-Acoustics TT-2002 musical test record without difficulty. Applause definition was excellent. The Shure Obstacle Course-Era III test record was played without difficulty. With the newer Shure Obstacle Course--Era IV test record, the harp and the harp and flute bands were just starting to mistrack at level 5. The flute and orchestral bells combination also started to mistrack at level 5. It is a rare cartridge, indeed, that can play all the bands of the Era IV test record without mistracking one or more high level bands.
Listening and Use Tests
As is our practice, our listening tests were performed both before and after laboratory testing of the SONUS Gold Series II Blue Label phono cartridge. While listening to the wide variety of records listed below, we became aware of the crisp sound, excellent transient response, good sonic clarity, and lack of detectable coloration. It encountered no difficulty in cleanly reproducing the high recorded levels present on most direct-to-disc recordings.
The SONUS cartridges are well-known for their extremely high compliance. Because of this, the cartridge under test encountered some difficulty with badly warped records where the cartridge "bounce" caused the cartridge body to momentarily resonate. However, since badly warped records are seldom played, particularly by the owners of systems in which this cartridge is likely to reside, this should not be a problem of consequence.
In conclusion, we find that the SONUS Gold Series II Blue Label is an excellent cartridge and ranks among the top cartridges we have tested.
-B.V. Pisha
Evaluation Equipment and Records
A rigorous listening evaluation was conducted utilizing the following equipment and the specific records listed below as well as many listed in past reports. The equipment included the Technics SP-10 and the SP-10 Mk II turntables with the Audio-Technica AT-1009 tonearm and the Technics EPA-100 tonearm, respectively, Crown IC-150A preamplifier, a pair of Crown DC-300A amplifiers used in the monophonic mode, a pair of stacked Duntech DL-15 speakers in each channel, and a Columbia SQL-400A SQ decoder. Each pair of speakers were connected to the amplifiers with Polk SoundCables using a Polk RC terminating network at the speaker end of each cable. The turntables were equipped with the Hiraoka Disk SE22 turntable mat.
The following records were among those used to aurally evaluate the performance of the SONUS Gold Series II Blue Label phono cartridge.
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Stereo
Domingo and Ricciarelli: Great Love Duets-RCA ARL1-2799.
Liszt: Piano Concerto No. 1 in E flat, Piano Concerto No. 2 in A major, Campanella (piano), Soudant, The London Philharmonic Orchestra--PYE PCNHX 7.
Ravel: Bolero; Debussy: Prelude a l'Apres-midi d'un faune, La Mer, Solti, Chicago Symphony Orchestra--London CS 7033.
Massenet: Scenes Alsaciennes, Scenes Dramatiques, Bonynge, National Philharmonic Orchestra-London CS 7048.
Verdi: Aida (Opera for Orchestra), Camarata, National Philharmonic Orchestra-London Phase Four SPC 21171.
Haydn: Symphony No. 51 in B flat, Symphony No. 55 in E flat (Schoolmaster), Dorati, The Philharmonia Hungarica-London Treasury Series STS 15443.
Rachmaninov: Rhapsody on a Theme of Paganini; Dohnany: Variations on a Nursery Song, Katchen (piano), Boult, London Philharmonic Orchestra-London Treasury Series STS 15406. Tricia-Ark Recording Co. 2218-S.
Vivaldi: Orlando Furioso, Scimone, Ente Orchestra da Camera di Padova-(Erato Collection) RCA ARL3-2869.
Verdi: La Forza del Destino,(Price and Domingo), Levine, London Symphony Orchestra--RCA ARL4-1864.
Verdi: II Trovatore, (Pavarotti and Sutherland), Bonynge, National Philharmon ic Orchestra--London OSA 13124.
Direct to Disc
Charlie Byrd-Crystal Clear Records CCS 8002.
Direct Disco-Crystal Clear Records CCS 5002.
Flamenco Fever-M & K RealTime Records RT-107.
Audio Directions presents The Grab Bag-ICM-R001.
Super Strings, Sugiyama, Tokyo String Ensemble-Toshiba LF-95010.
Intensive Care, Bellson, Brown, Smith--Discwasher Recordings DR 001 DD.
Pulse Code Modulation (PCM)
Janos Starker plays Virtuoso Music for Cello-Denon OX-7140-ND (distributed by American Audioport, Inc.).
Bach: L'Offrande Musical, Paillard, Les Solistes de Orchestre de Chambre--Denon OX-7021-ND (distributed by American Audioport, Inc.).
Quadraphonic--SQ
Santana Festival--Columbia PCQ 34423.
Bartok: The Wooden Prince, Boulez, New York Philharmonic-- Columbia 34514.
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(Source: Audio magazine, Jul. 1979)
Also see:
SONUS Blue Label Phono Cartridge (Equip. Profile, April 1977)
Sonus Dimension 5 Cartridge (Mar. 1982)
Dual Model 1249 Automatic Turntable (Feb. 1977)
ADC Model LMF-2 Tonearm & ZLM Phono Cartridge (Jan. 1979)
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