Solid State Preamp Reviews

It is this ability to convince the listener that there is apparently limitless power in reserve, coupled with a wealth of detail that is presented in a musically natural fashion, that most impresses me about the No.20.5. With lesser, if still worthy, amplification, there is a level of added fuzz that overlays the sound to an extent dependent on absolute level. As the music plays softly, all is well. But as things either get louder or more complicated, individual instrumental or vocal voices start to lose that individuality, the whole starting to blend, much as they do on all but the very best CD players. I often find that this character reveals itself mainly over longer-term listening and then, more in the way I choose what to play. If my listening diet starts to mainly feature chamber works, for example, then this is a strong pointer that something is not right in the amplification chain. With an amplifier like the No.20.5, however, that diet swings strongly over to red-blooded orchestral works, from Strauss, Sibelius, and Elgar, where the complex scoring is decoded that essential bit more clearly.

Slapping the RCA budget CD re-release of the 1962 Reiner performance of Strauss's Also Sprach Zarathustra (RCA "Papillon" 6722-2-RG) on to the Tempest, though organ pedal and double-basses provide the weight of the low-C purr before sunrise, it is the harmonics of a contrabassoon note that provide the higher-frequency outline. With either SL700s or Sequels driven by the Mark Levinsons, this is perfectly apparent, and when the timps belt out their tonic-dominant proclamation, not one element of the background pedal is disturbed—just as it is in reality. Comparing this classic performance with that of Gerard Schwarz (excerpted on The Symphonic Soundstage, Delos D/CD 3502), the differences in the sound quality of the microphones used in 1962 and 1987 are quite apparent (footnote 2). Yet again, the contrabassoon can be heard to "point" the texture of the pedal C, and the timps neither interfere with this bass background nor are interfered with by it. This is the sign of an amplifier with iron control over the loudspeaker it drives.

Despite intensive listening, I am forced to admit that, apart from its ability to extract a powerful bass performance from just about any speaker and this musically honest presentation of fine recorded detail, I was unable to detect any degree of "character" in the midrange and treble. The No.20.5 seems truly to be a "non-amplifier," in that what you hear is entirely the business of the recording, the playback system, and the preamplifier.

Perhaps careful comparisons with competing products would show up its signature. I said at the beginning of the review that some things are a matter of timing. Particular comparisons I had wanted to perform were to see how the No.20.5 compared with both the VTL 300W monoblock, which is perhaps the finest-sounding tube amplifier I have heard, and either the Krell KSA-200 or a pair of KMA-160s, which are two of its closest solid-state peers. Unfortunately, the VTLs still grace J. Gordon Holt's listening room, where they seem embedded in concrete. As Krell seems no longer to want to work with magazines by submitting review samples of their products, we bought a KSA-200 at retail. Or rather, we are still in the process of buying one at retail: having paid for it, Krell appears to be so back-ordered that actual delivery, which I had hoped would occur in June, in time for this review to include the specific comparison, had still not occurred by the end of July. As I said, it's a matter of timing.

The only similarly priced (I use the term loosely) power amplifier with the potential of offering competitive sound quality available in Santa Fe at the time of writing was the $7000/pair Prodigy 150 OTL tube amplifier, reviewed by Dick Olsher in this issue. Accordingly, I set up both pairs of amplifiers with the Celestion SL700s and listened hard to what they had to offer.

There is no doubt that the tube amplifier is an excellent performer, particularly in the reproduction of recorded space and ambience, as noted by DO. Compared with the 20.5, however, the Prodigy's tonal balance was definitely on the lightweight side, low frequencies sounding a little rolled off and the treble rather wispy, coupled with a degree of that added "fuzz" or congestion at high levels. On the plus side, the degree of spaciousness to the sound presented by the Prodigy was only just rivaled by the Levinson. Using—horrors—the cassette copy of the edited master tape of Stereophile's first record (see full report in this issue), the sound of the hall via the tube amplifiers was just that bit more true to what I remember it was like when listening to the musicians live. Overall, however, the No.20.5 presents a more balanced performance, without any particular weakness. And both its battleship construction and the company's enviable record for reliability are important factors when choosing a pair of power amplifiers that cost as much as a small car. But when the Madrigal design team get round to the next revision, "Just a little more space around the soundstage, please," would be my request.

Conclusion
In view of the non-availability to me of the Krell and VTL power amplifiers at the time of writing, this review should perhaps be considered more a progress report than a definitive statement. However, there is no doubt in my mind that the Mark Levinson No.20.5 is the best amplifier overall I have yet heard in my system. Any sonic signature was conspicuous by its absence, apart from the paradoxical fact that loudspeakers sounded both more like themselves and had less degrading effects on the music. Similarly, the No.20.5 allows orchestral instruments to retain more of their own individuality when the scoring grows complex, something that I am beginning to demand from amplification.

Enthusiastically recommended, the No.20.5 is a true reference power amplifier—for the rich. It wouldn't be too much to say that it enables any loudspeaker it drives to give of its best...which, of course, is the fundamental specification for any power amplifier.—John Atkinson

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Footnote 2: That a good engineer was at the wheel of each Zarathustra recording is shown up by the Leontyne Price Four Last Songs from 1973, included on the RCA CD. Her voice is unnaturally spotlit, large, and forced, significantly subtracting from any feeling of musical involvement. (Elisabeth Schwarzkopf, on EMI CDC 7 47276 2, from 1966, is the version to get of these most moving of all Richard Strauss's works, in my humble opinion.)—John Atkinson