Monster Cable Alpha 2 Cartridge (Equip. Profile, Apr. 1987)

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MANUFACTURER'S SPECIFICATIONS

Type: Moving coil

Frequency Response: 10 Hz to 60 kHz; 20 Hz to 20 kHz, ± 1 dB.

Stylus Rake Angle: 0°, ± 2° with VTA set at 19° to 22°.

Channel Separation at 1 kHz:

Greater than 30 dB.

Vertical Tracking Force: 1.75 grams.

Channel Balance: 0.2 dB.

Stylus Shank: Nude, square, 0.1 mm.

Stylus Tip: Micro-Ridge, 3 x 80 microns.

Cantilever: Thin-wall hollow sapphire; 0.33-mm outer diameter, 0.26-mm inner diameter, 5.8 mm long.

Recommended Load Impedance: 30 ohms (optimum) to 80 ohms.

Internal Impedance: 4 ohms.

Compliance at 11 Hz, 70° F: 15 x 10^-6 cm/dyne.

Output Voltage at 1 kHz, 5 cm/S: 0.3 mV.

Weight: 6.5 grams.

Price: $650; replacement stylus, $390.

Company Address: 101 Townsend St., San Francisco, Cal. 94107.

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Since my review of the Alpha 1 cartridge (Audio, January 1984), there seems to have been no diminution of the number of new, high-end phono cartridges. It also appears that the makers of these cartridges are not alarmed by the rise of CD. Monster Cable certainly isn't; they have since introduced the Alpha 2 in both the low-output version re viewed here and a high-output version.

The new cartridge uses the "magnetic feedback control" circuit Monster Cable introduced in the Alpha 1 to eliminate unwanted Foucault or eddy currents which usually develop in magnetic circuits. The Alpha 2 also incorporates a hollow, tube-type cantilever, made of sapphire, upon which is mounted an extended-footprint stylus. The stylus is the Namiki Micro-Scanner, which is said to have a relatively constant tip radius of between 2 and 3 microns to allow better tracing of inner and outer grooves, with very low distortion. The manufacturer recommends that the cartridge be broken in for about 10 hours to realize full performance.

The Alpha 2 comes packaged in a beautifully machined, black-anodized aluminum "pill box" with walls 1/4 inch thick.

Besides the cartridge, the package contains various screws and tools that are needed to mount the cartridge, plus a vial of Stylast. The aluminum container is located within the two halves of a styrofoam box, which in turn is enclosed in a nice-looking display box.


Fig. 1-Frequency response (top curve) and separation (bottom curve), after phono cartridge was demagnetized. Test record is CBS STR-170.

Measurements

Due to the minute size of the moving coils, the direct signal output is very low, i.e., 0.38 mV; thus, a step-up device is necessary to raise the output voltage to a level high enough to work with the usual preamplifier phono gain stages. Accordingly, most of the measurements reported here were made using my measuring amplifier and re checked with an Electrocompaniet MC-2 pre-preamp or with a Technics SH-305MC step-up transformer set to 30 ohms. The frequency response of the transformer has been measured as ±0.5 dB from 40 Hz to 50 kHz. However, all musical evaluation was done with the Electrocompaniet MC-2 pre-preamp.

The Alpha 2 was mounted in a Technics magnesium headshell and used with a Technics EPA-250 interchange able tonearm. The arm was attached to a Technics EPA-500 tonearm base mounted on a Technics SP-10MK2 turntable.

The Alpha 2 was oriented in the headshell and tonearm with the Dennesen Geometric Soundtracktor. All laboratory tests were conducted at an ambient temperature of 73° F (22.78° C) and a relative humidity of 80%, ±3%.

I performed my usual pre-testing listening evaluation, which normally runs about 10 hours, in order to determine whether to continue the review and, at the same time, to complete the recommended "break-in" time prior to making any laboratory measurements. Initially, I found that the optimum tracking force for this cartridge was 2.8 grams rather than the recommended 1.75 grams, and that the optimum anti-skating force was 3.0 grams. I also found that the cartridge performed surprisingly poorly on the three Shure Audio Obstacle Course test records. I then requested a second sample, which did manage to pass a number of the Shure test bands at a satisfactory level but still required a 2.8-gram tracking force.

While I was pondering this turn of events and wondering how I should present this review to the readers of Audio, I received a telephone call from an audiophile friend, Sherwin Janows, of Chicago. He called to tell me about a new gadget from Sumiko, the "Fluxbuster" FB-1 demagnetizer, which actually demagnetizes magnetically permeable components of a transducer. Sumiko's David Fletcher claimed that the Fluxbuster actually restores a cartridge's loss of dynamics. My first thought was to ask Mr. Janows if he would loan me the Fluxbuster to try on the Alpha 2.

In due course the Fluxbuster arrived. Before I used it I rechecked the Alpha 2 and got the same results. Then I demagnetized both cartridges, using the Fluxbuster three consecutive times to be certain that all unwanted magnetism was removed. I was not certain that the cartridges were magnetized but wondered if somehow they had developed eddy currents in their circuitry despite the control circuit which was designed to eliminate them.

When the process was completed, I inserted the cartridge and headshell into the tonearm, made the necessary adjustments, and proceeded to listen to the Shure Audio Obstacle Course test records once more, expecting to declare the Alpha 2 unacceptable for true high-fidelity use. Suddenly the solo violin, which had previously sounded unbelievably strident and harsh, sounded like a true violin. As I listened, in a state of disbelief, I thought this bordered on chicanery--that I had performed some black magic and that in the morning everything would return to its original state of poorly reproduced music. However, I couldn't let go of the cartridge, and continued to search for the answer to what had happened with the Fluxbuster. Further, I now found that the optimum tracking force had gone from 2.8 grams down to 1.8 grams (close to the recommended tracking force of 1.75 grams) with an optimum anti-skating force of 2.1 grams. Every test record was passed by the rejuvenated Alpha 2 except for the Telarc "1812 Overture" (matrix 11), where three of the cannon shots were impossible for the Alpha 2 to track. However, I consider this a fantastic achievement, especially as that disc had proved impossible for the cartridge to handle before demagnetizing.

After I had reassured myself that the Alpha 2 moving-coil phono cartridge was going to maintain its new characteristics, I discussed the matter with Monster Cable's president, Noel Lee. He was astonished by my findings and by the solution to the problem. He immediately told me to tell our readers that anyone owning an Alpha 2 which they believe is magnetized should return it to Monster Cable for a free demagnetization. In the future, Monster Cable will demagnetize all their cartridges before shipping.


Fig. 2--Response to a 1-kHz square wave.

The tracking force for all reported tests was set at 1.8 grams, with an anti-skating force of 2.1 grams. During the past decade or so, a well-known reviewer and I have always stated that the anti-skating setting for any cartridge should be greater than the tracking force. On occasion it was only a few milligrams greater, but greater it was! Finally, a manufacturer has acknowledged this: Monster Cable has pack aged a note with each Alpha 2, stating that it requires more anti-skating compensation than most tonearms indicate be cause of its unique stylus shape. The company recommends an increase of about 30%, which they say will pro vide "unparalleled low distortion" in tracking high-velocity grooves. I question this statement (for one thing, I found the optimum anti-skating to be only 17% more than indicated), but since I do not wish to engage in any unresolvable discussions, I will "pass" on this subject.

To continue, then, the load resistance was 47 kilohms and the load capacitance was 70 pF. As is my practice, measurements were made on both channels, but only the left channel is reported here 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, and STR 170; Shure TTR-103, TTR-109, TTR-110, TTR-115, and TTR 117; Deutsches HiFi No. 2; Nippon Columbia Audio Technical Record (PCM) XL-7004; B & K OR-2010; and Ortofon 0002 and 0003.

Frequency response using the Columbia STR-170 test record (Fig. 1) was -0.5, +5.5 dB from 40 Hz to 20 kHz.

Response was ± 1 dB from 40 Hz to 5 kHz, +2.5 dB at 10 kHz, +4.5 dB at 15 kHz, and +5.5 dB at 20 kHz. Separation was 23.75 dB at 1 kHz, 25 dB at 10 kHz, 22 dB at 15 kHz, and 18 dB at 20 kHz. (The rise in the frequency response from 6 to 20 kHz is typical of most moving-coil phono cartridges.) The 1-kHz square-wave response (Fig. 2) is consistent with that seen for most moving-coil cartridges, when there is a large overshoot (equal in amplitude to that of the square wave itself) followed by a low-level ringing that decays rapidly. The ringing is undoubtedly due to a relatively un damped stylus resonance that takes place at about 37 kHz.

To measure the arm/cartridge low-frequency resonance, it was necessary to disable the tonearm's anti-resonance de vice. The arm/cartridge low-frequency lateral resonance for the left channel was at 8 Hz. Vertical resonance was at 9 Hz.

Neither the lateral nor the vertical low-frequency resonance was measurable when the tonearm's anti-resonance device was used.

Using the Dynamic Sound Devices DMA-1 analyzer, the arm/cartridge dynamic mass was measured as 21.5 grams and the dynamic vertical compliance as 25 x 10^-6 cm/ dyne at 8 Hz. The vertical stylus angle measured 22°.

Other measured data are: Wt., 6.25 grams. Opt. tracking force, 1.8 grams. Opt. anti-skating force, 2.1 grams. Output: 0.11 mV/cm/S measured directly, 1.7 mV/cm/S using the pre-preamp. IM distortion (200/4000 Hz, 4-to-1): Lateral (+9 dB), 1.7%; vertical (+6 dB), 6.0%. Crosstalk (using Shure TTR-109): Left,-28 dB; right,-28 dB. Channel balance, 0.25 dB. Trackability: High freq. (10.8 kHz, pulsed), 30 cm/S; mid-freq. (1000 and 1500 Hz, lateral cut), 31.5 cm/S; low freq. (400 and 4000 Hz, lateral cut), 24 cm/S.

The Deutsches HiFi No. 2, 300-Hz test band was tracked cleanly to 86 microns (0.0086 cm) lateral at 16.20 cm/S at +9.66 dB and to 55.4 microns (0.00554 cm) vertical at 10.32 cm/S at +5.86 dB.

The demagnetized Alpha 2 played all the test bands on the Shure Obstacle Course Era Ill musical test record. On the Era IV musical test record, the Alpha 2 passed all the test bands except for the flute and the harp-and-flute bands, where it passed the fourth level. All six levels of the Shure Obstacle Course Era V test record were tracked without a mishap. I might add that it is a rare cartridge that is able to track all the peak recorded velocities on these records, some of which exceed 50 cm/S. (The peak recorded velocities of analog records average about 15 cm/S).

Use and Listening Tests

As is my practice, I performed listening tests both before and after the laboratory measurements. Normally, the results of my first two hours of listening would have been sufficient for me to disqualify the cartridge from further testing. I made an exception in this instance, however, because the earlier Alpha 1 was above average. As the results grew progressively worse, curiosity made me decide to continue with the testing.

Since one does not listen to laboratory measurements, it is very important to evaluate a cartridge by listening to a wide variety of recordings over a reasonable length of time.

Accordingly, I listen mostly to unplayed or virgin records for about 10 hours before making any measurements. Should a phono cartridge be defective, its problems will generally show up during this time.

As I have stated before, my philosophy regarding the testing of phono cartridges is that the listening evaluation should be the final criterion by which a cartridge is judged.

After all testing is completed, I spend at least another 10 to 25 hours (sometimes as much as 40 hours) evaluating the cartridge with a large variety of recorded music from my vast library. It is during this listening evaluation that I reach a conclusion on the merits of a given cartridge. I strongly believe in the axiom put forth many years ago by the late C. J. LeBel: "If it measures good and sounds bad, it is bad." The equipment used in the listening evaluation included the aforementioned Technics turntable and tonearm, an Audio-Technica AT666EX vacuum disc stabilizer, a Levinson ML-1 preamplifier and ML-3 amplifier, speaker and interconnecting cables from Discrete Technology and Monster Cable, the Discrete Technology LSI CD player, a pair of B & W 801F speakers, and a pair of Janis W1 subwoofers, each located next to one of the 801Fs. (The lnterphase 1A amplifier/crossover units for the W1s are located in the laboratory.) The speakers are located in the dead end of my listening room, positioned for optimum response as deter mined by measurements made with the Tecron TEF-10 system.

I compared several analog discs with their CD versions when both had been derived from the same digital master tape. One of the recent releases I listened to was the Telarc Bachbusters, DG-10123 on DMM vinyl, CD-80123 on CD.

Somewhat to my surprise, I preferred the DMM vinyl version as played by the Alpha 2. Possibly because of the Alpha 2's rising high-end response, the sound came through more distinctly and clearly on the LP than on the CD. However, it must be understood that after repeated plays (about six), the vinyl record will progressively lose its high end while the CD will suffer no alterations. The DMM recordings give the CD versions some very tough competition, but they have to lose in the end.

During the listening evaluation, the Alpha 2 was very revealing, was free of coloration, and possessed excellent clarity and tight bass. The depth of image was also excellent. The sound of the Bosendorfer Imperial piano on my test disc came through beautifully, as did the general resolution of the various other musical instruments. Applause definition was excellent.

After I had demagnetized the Alpha 2, it was able to handle almost any high-velocity recorded material. How ever, it was unable to negotiate three of the cannon shots on the Telarc "1812 Overture" (matrix 16) and the flute and the harp-and-flute combination on the Shure Era IV Obstacle Course musical test record. These are difficult tests.

I should recommend the following superb recordings (in addition to the aforementioned Bachbusters) which were culled from the numerous records I auditioned in connection with my review of this cartridge: Rachmaninoff's "Piano Concerto No. 2" (The Royal Philharmonic, Horenstein, Chesky Records CR 2, DMM); Berlioz's Requiem (Boston Symphony Orchestra, Munch, RCA Red Seal ATL 2-4269); Still Harry After All These Years (Harry James & His Big Band, Sheffield Lab 11); Beethoven's String Quartets, No. 11 and No. 12 (Smetana Quartet, Denon OF-7021); Marni Nixon Sings Gershwin (Reference Recordings RR-19); Gershwin's "Rhapsody in Blue" and "An American in Paris" (Cincinnati Symphony Orchestra, Kunzel, Telarc DG-10058); Live at the London Palladium (Judy Garland and Liza Minnelli, Mobile Fidelity Sound Lab MFSL 1-048); Back to Birdland (Freddie Hubbard, RealTime Records RT-305, digital); and Beethoven's "Sonata in G Major, Op. 96" and Enescu's "Sonata No. 3, Op. 25" (Wilson Audio W-8315).

With every Alpha 2 moving-coil phono cartridge now being demagnetized prior to shipping, I can recommend it without hesitation or reservation to all serious music lovers.

--B. V. Pisha

(Source: Audio magazine, Apr. 1987)

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