Convergent Audio Technology SL-1 preamplifier Page 3
The Soundstage—Depth: The original MC-7 had superb, if slightly exaggerated, depth. The improved Motif provides this same depth, but with more detail and less exaggeration. it is perhaps the most musically realistic preamp to date in this performance area. The SP-10/II has a bit less depth, placing instruments a bit more forward.
The Audio Research SP-11 seems a bit more realistic than either the MC-7 or SP-10/II, but has less apparent depth with most records. The SP-11 does, however, suddenly acquire more depth and detail when the record or tape actually has the information. Once again, the Convergent Audio Technology has much the same sound character as the SP-11, and is only slightly less detailed and revealing.
The Soundstage—Imaging: All four preamps do a consistently good job of portraying imaging on both the simplest and most complex music—a consistency normally lacking in even the most expensive competition.
The Motif MC-7 still excels any previous CJ design in its ability to fix a given performer or instrument in a convincing arc of left to right placement without any sacrifice of centerfill. It is rivaled only by the SP-10/II in this regard, and the MC-7 may have superior overall ability to provide the full arc of imaging without any emphasis of the center or sides.
Both the SP-11 and C.A.T. SL-1 tend to favor the center—only slightly, provided that extreme care is taken with the balance control to get things exactly right, which isn't easy with stepped balance controls. This may or may not indicate that the MC-7 and SP-10/II romanticize the imaging.
The Soundstage—Hall Position: The improved Motif MC-7 retains the traditional tendency of CJ equipment to make it seem if you were sitting mid-hall, rather than forward, although the improved MC-7 clearly outperforms the Premier Three and any previous CJ preamp at making this seating position seem realistic. There are many small musical details—hall noise, percussion transients, bowing noises, etc.—which come through during phono playback using the MC-7 that are blurred or missing with the Premier Three. These details also come through in a musically natural way. In fact, the more you listen to the Motif, the more you will notice additional data about a recording's location, multi-tracking, and/or mixdown.
The SP-10/II and SP-11 have a more forward character, but are both very revealing. If the Motif MC-7 is Row N, the SP-10/II is row H, the SP-11 rows E-F. The Convergent Audio Technology is Row F-H.
All four preamps have a consistent ability to place you in the hall. The Motif MC-7 makes you sink back into the music, almost relax into it as you find yourself listening to the full atmosphere, harmonic detail, and timbre natural to a mid-hall seating position. The Audio Research SP-10/II remains the most attention-grabbing preamp ever made. You feel like you are in the best seat in the house even as your mind tells you that the SP-10 may be improving slightly on the signal source to give you this impression.
The Audio Research SP-11 and C.A.T. are less musically involving, but are also probably more neutral. They do a more realistic job of reproducing records and reflecting the differences in apparent listening position, without imposing the preamp's sound character of the preamp. At the same time, you are less likely to hear hall or listening position effects on records where the presence of such information is uncertain.
Overall Dynamics and Transient Life: The improved Motif MC-7 has more transparency and dynamic life in soft passages than the early version, and has more accuracy and resolution in this regard than the Audio Research SP-10/II and Premier Three, particularly with low- to moderately low-output moving coils. The SP-10/II is very dynamic at moderate listening levels, but loses detail in its noise floor on soft passages. Both preamps function very well during loud, dynamic passages, although the SP-10/II may be slightly superior.
The SP-11 is a bit restrained in comparison with both the MC-7 and SP-10/II, but this restraint seems more natural in prolonged listening. It is superb in reproducing the full impact of dynamics and transients from the softest passages up. The C.A.T. SL-1 is weakest in this area. It has competitive detail and speed, but seems not quite as dynamic as the others.
Sonic Consistency No Matter the Gain: Both the Motif MC-7 and Audio Research SP-10/II suffer from slightly higher coloration in their high-level stages than do the SP-11 and Convergent Audio Technology SL-1. The MC-7 seems to make both the sound from its moving-magnet inputs and high-level gain stages a bit too dynamic, and seems to add soundstage depth and width not present in the original signal. At its best, the moving coil stage has no more coloration than the other gain stages. The MC-7, however, is a hard preamp to load. It does not seem fully comfortable with loads below 100 ohms, which can slightly reduce dynamics, warmth, and deep bass energy. The right load for a given cartridge is hard to predict; it can be in excess of 500 ohms, where the same cartridge with another preamp might sound best with a 30 ohm load. This preamp is at its best with relatively high-impedance loads for moving coil cartridges.