Manufacturer's Specifications:
Type: High-output, moving-coil.
Frequency Response: 20 Hz to 20 kHz, ± 1.5 dB.
Channel Balance: Within 1 dB.
Channel Separation: 23 dB minimum from 200 Hz to 10 kHz; 20 dB minimum from 10 to 20 kHz.
Recommended Tracking Force Range: 1.5 to 2.1 grams.
Output Voltage: 2.5 mV at 3.54 cm/ S rms at 1 kHz.
Cartridge Weight: 5.0 grams.
Mounting: Standard 0.5 inch (12.7 mm) centers.
Recommended Load Impedance: 47 kilohms (non-critical); capacitance, non-critical.
Cantilever: Thin-walled, high strength extruded aluminum alloy.
Vertical Tracking Angle: 20°.
Dynamic Compliance: 8 x 10^-6 cm/dyne at 100 Hz.
Stylus: van den Hul, 0.14 x 3.3 mil (3.5 p. x 85 µ), grain-oriented, square-shank diamond, nude mounted.
Effective Tip Mass: 0.27 milligram.
Tracking: 70-11m amplitude, 300-Hz lateral modulation at 1.8 grams.
Price: $200.00.
Company Address: 247 Lynnfield St., Peabody, Mass. 01960, USA.
There seems to be a new trend developing in the field of audio transducers-speaker manufacturers introducing their own brands of phono cartridges. The latest entries come from Boston Acoustics, with two moving-coil cartridges, the MC-1vdH reviewed here and the MC-1 E. They are identical except for their styli, with a van den Hul in the former and a standard elliptical stylus in the latter. It is most surprising that all manufacturers of electromechanical and mechano-electrical transducers have not joined forces long ago, since their products have the greatest effect on the sound of a high-fidelity system.
The MC-1vdH is a low-impedance, moving-coil phono cartridge with two horizontally opposed coils for each channel, producing a greater output than the usual moving-coil designs. Thus, there is no need for a step-up transformer or a pre-preamplifier. Further, Boston Acoustics states that the MC-1vdH's low effective moving mass results in an armature resonance above the audible range, without the need for an exotic, expensive, high-Q cantilever material. Channel separation is maintained to 20 kHz, groove tracing is improved, and record wear is minimized because the resonance is low Q and is not excited by audio signals.
The MC-1vdH, with its low mass and moderate compliance, is compatible with most any tonearm (e.g., low, medium, or high mass) and with just about any preamplifier, according to Boston Acoustics.
The MC-1vdH is fitted with the stylus tip developed by A. J. van den Hul of Delft, The Netherlands. The shape of this stylus tip resembles that of the cutting stylus, but instead of the cutter's 2-µ radius, it has a radius of 3.5-µ. Because of this small front-to-back contact radius, only a small part of the record groove is traced at any one time, with only one specific moment of tracking for any portion of the groove.
Thus, the tip movement is precisely the same as the groove modulation. The vertical groove-contact line is exactly vertical, with no curvature, and its radius measures 85 µ. The stylus is a grain-oriented, square-shank diamond, nude-mounted on the aluminum alloy cantilever. (For a further discussion of the van den Hul stylus tip, see my comments on page 62 of the November 1981 issue of Audio.) The cartridge comes with the necessary mounting hardware, a small screwdriver, and a small paper alignment protractor that is quite accurate.
Since the cartridge is rectangular with straight edges, it is quite easily installed with the aid of the protractor.
Boston Acoustics has provided its dealers with an aluminum alignment gauge that permits absolutely accurate alignment of the MC-1vdH (or the MC-1E) in the headshell and tonearm.
=============
FORETASTE OF THE FUTURE?
It is ironic, now that the digital Compact Disc has been launched, such a plethora of high-quality phono cartridges have been introduced recently, among which the Boston MC1vdH ranks very highly. If this is nearly the last hurrah for phono cartridges, they are certainly not going out with a whimper. . However, in comparing the relative qualities of today's cartridges and records with CD players and discs, some observations are in order. I have been fortunate in having a superb Telarc LP and CD made from the same digital master tape, Stravinsky: The Firebird and Borodin: Music from Prince Igor, Overture and Polovetsian Dances (Telarc DG-10039 and CD-80039). To conduct an experiment, I used a pair of B & W 801S speakers and the Technics SL-P10 CD player, with its very accurate cueing mechanism, in addition to the components cited above. I set the sound level so that the speakers would provide what I consider my normal room listening level, at an SPL of 85 dB, C-weighted (dBC), at 10 feet for the identical forte passage.
(My listening room is a modified live-end, dead-end type.) Under these conditions, the CD version provided an SPL of up to 10 dBC greater dynamic range than the same passage on the LP version. (Telarc's chief engineer, Jack Renner, has assured me that they use neither compression nor limiting when making the original digital tape.) The limitations of cutting geometry simply would not accommodate this 10-dBC increase, and thus the dynamic range on the CD more accurately reflects the dynamic range of the digital master recording.
Irrespective of sheer numbers, the comparative listening experience incontrovertibly provides a much more exciting insight into the music, and that SPL of 10 dBC looms very large in terms of emotional impact.
While the Boston Acoustics MC1vdH phono cartridge acquitted itself admirably, neither it nor any other phono cartridge can possibly challenge the superior sonic qualities of this Telarc Compact Disc. The digital recording is free of wow and flutter and the usual hiss and impulse noise associated with the playback of analog phonograph records.
Even for the highest quality audiophile recordings, a dynamic range of 62 to 64 dB is the best usually achieved in conventional mastering.
It is true that, through the use of such new techniques as direct metal mastering, there can be further improvement in dynamic range. However, the DMM process is expensive and not likely to become the standard cutting technology any time soon. Most important, even if an analog phonograph record could equal the performance parameters of a digital disc, this quality would be very transitory, as the inevitable stylus/groove wear would ultimately destroy the recording, while the non-contact laser beam playback would assure premium sound quality forever.
I hasten to add that, at present, there are very few CDs of the quality of Telarc's The Firebird. However, it is inevitable that, with time, most of the digital discs can be expected to equal or better this level of quality.
Am I saying that the death knell has sounded for analog phonograph records? Certainly not! Analog recordings will continue to be produced for many years, but it would be foolish to suppose that they could stem the digital tide indefinitely.
-B. V. P.
=============
Measurements
The Boston Acoustics MC-1vdH phono cartridge was mounted in an Audio-Technica AT-N headshell and used with the Technics EPA-A250 (S-shaped) interchangeable tonearm unit attached to the Technics EPA-500 tonearm base, which was mounted on a Technics SP-10 Mk II turntable. The cartridge was oriented in the headshell and tonearm with the aid of the Dennesen Geometric Soundtracktor. When the cartridge alignment was finalized, I checked it against the paper alignment protractor supplied with the cartridge and found it to be accurate. That alignment was checked against the Boston Acoustics aluminum alignment gauge, and the gauge was found to be very precise.
Fig. 1--Frequency response and separation.
Fig. 2--Response to a 1-kHz square wave.
Laboratory tests were conducted at an ambient temperature of 70° F (21.11° C) and a relative humidity of 73%, ±3%. The manufacturer's recommended stylus tracking force of 1.8 grams was used for all laboratory measurements and listening tests. The anti skating force was set at 2.0 grams. The load resistance was 47 kilohms, and the load capacitance 241 pF. As is my practice, measurements are made on both channels, but only the left channel is reported unless there is a significant difference between the two channels (in which case both channels are reported for a given measurement). The following test records were used in making the reported measurements: Columbia STR-100, STR-112, STR-170; Shure TTR-103, TTR-109, TTR-110, TTR-115, TTR-117; Deutsches HiFi No. 2, B & K OR-2010, and Ortofon 0002.
Frequency response, using the Columbia STR-170 test record (Fig. 1), was 0 dB at 40 Hz, + 1.75 dB at 50 Hz, -0.5 dB at 8 kHz, 0 dB at 12 kHz, and +1.5 dB at 20 kHz. The overall frequency response was +1.75, 0.5 dB from 50 Hz to 8 kHz and -0.5, + 1.5 dB from 8 to 20 kHz.
Separation was -21.5 dB at 1 kHz,-24 dB at 10 kHz,-20.5 dB at 15 kHz, and -18.5 dB at 20 kHz. It is apparent from these data that the MC-1vdH phono cartridge has a relatively flat frequency response and a good high-frequency separation. The 1-kHz square-wave response (Fig. 2) is typical for a moving coil cartridge, with a minimal overshoot followed by some low-level ringing, which is undoubtedly present on the test record, After disabling the arm's anti-resonance system, the arm-cartridge lateral low-frequency resonance was measured as 9 Hz with a 4-dB rise. The high-frequency resonance point was at 20 kHz.
The arm-cartridge dynamic mass was measured as 13 grams, and the dynamic vertical compliance as 11.5 x 10^-6 cm/dyne at the vertical resonant frequency of 13 Hz.
The harmonic distortion components of the 1-kHz, 3.54 cm/S rms, 45° velocity signal from the Columbia STR-100 were 1.78% second harmonic and 0.40% third harmonic, with less than 0.20% higher order terms.
The vertical stylus angle measured 24.5°, using the Vertical Tracking Angle Meter (Inclination Meter), Model 3002, developed by the CBS Technology Center.
Other measured data are: Wt., 5.0 g. Opt. tracking force, 1.8 g. Opt. anti skating force, 2.0 g. Output, 0.71 mV/ cm/S. IM distortion (200/4000 Hz, 4-to 1): Lateral (+9 dB), 0.8%; vertical (+6 dB), 3.6%. Crosstalk (using Shure TTR109): Left,-27 dB; right, -24 dB. Channel balance, 0.4 dB. Trackability: High-freq. (10.8-kHz, pulsed), 30 cm/ S; mid-freq. (1000 and 1500 Hz, lat. cut), 25 cm/S; low-freq. (400 and 4000 Hz, lat. cut), 24 cm/S; Deutsches HiFi No. 2, 300-Hz test band was cleanly tracked to an amplitude of 77 microns (0.0077 cm) lateral at 14.50 cm/S at +8.70 dB and to 55.4 microns (0.00554 cm) vertical at 10.32 cm/S at +5.86 dB. The MC-1vdH played all the test bands cleanly on the Shure Audio Obstacle Course Era III musical test record. On the Shure Audio Obstacle Course Era IV, the cartridge experienced a mild difficulty when tracking level 5 of the harp and flute test bands.
The cartridge responded extremely well, considering that the velocities of the combined instruments, harp and flute, exceed 45 cm/S. (Commercial records rarely exceed 15 cm/S peak recorded velocity.) The Shure Audio Obstacle Course Era V test record was tracked without difficulty at all levels.
Use and Listening Tests
While auditioning the MC-1vdH prior to making any laboratory tests, I was quite impressed with its smooth sound, excellent stereo imaging, and sonically well-defined and tight bass. The laboratory data appear to confirm what my ears had already told me. The musical evaluation was made with the following equipment: The aforesaid tone arm and turntable, the Audio-Technica AT-666EX vacuum disc stabilizer, Crown IC-150 preamplifier, Audire DM 700 power amplifier, and a pair of Pentagram P-10 full range loudspeakers that reproduce bass below 25 Hz without the need of a subwoofer. Following the speaker manufacturer's recommendation, the P-10s were connected to the amplifier with 4PR Kimber Kable in parallel with Live Wire cable.
During the final listening evaluation, I was particularly impressed with the cartridge's ability to reproduce the high recorded velocities found on most audiophile records, including the cannon fire present on the Tchaikovsky 1812 Overture (Telarc 10041). Tracking ability, transparency of sound, and transient response were all very good.
Some of the exceptionally good records I used to audition the MC-1vdH were Organasm (Warren Lubich, organist, Sonic Arts LS-15), Poulenc: Gloria and Organ Concerto (Atlanta, Shaw, Telarc DG-10077), Sibelius: Four Legends from the Kalevala (Philadelphia, Ormandy, Mobile Fidelity MFSL 1-523) and RCA's superbly re mastered recording of Rimsky-Korsakov's Scheherazade (Chicago, Reiner, RCA Red Seal Point Five ARP1 4427). To sum up, the Boston Acoustics MC-1vdH should be considered as a superb choice for anyone desiring a top-notch, high-output moving-coil phono cartridge.
-B. V. Pisha
(Audio magazine, Feb. 1984)
Also see:
Boston Acoustics A40 Speaker (Equip. Profile, July 1983)
Boston Acoustics T1030 Speaker (Jan. 1991)
= = = =