Tube Power Amp Reviews

Nonetheless, it was another day or two before I could get the Raven Spirit up and running: As with the mono versions, the review sample arrived without a manual, and the first tube chart I received, via e-mail, proved to be out of date. (I discovered that not with pyrotechnics, but by noting that the amp wasn't shipped with the same complement of tubes as described in the chart.) A new chart arrived soon thereafter, and proved correct.

With the Raven Spirit on the floor—it was too large for my Box Furniture equipment rack—and roughly midway between my preamp and the left-channel loudspeaker, I rechecked the tube installation and cabling, then timidly turned the power switch. I heard a very few quiet, intermittent pops and hums. The latter were mostly in keeping with what one would hear from many otherwise fine amplifiers, as the power-supply capacitors charged up, but a mild hum endured in the left channel with both sets of power tubes. If not for my history with this amp's predecessor, I might have switched some of those NOS small-signal tubes from one channel to the other, to isolate the problem, but that seemed unwise. I might also have tried floating the AC ground, but—notably—the owner's manual specifically warns against doing so. Similarly and, I think, understandably, I was reluctant to operate the Raven Spirit upside-down and with its casework open, as would be necessary to adjust the hum pots. So I didn't.

Listening
The first album I used to audition the Raven Spirit was Gerry Mulligan Meets Ben Webster (mono LP, Verve MG V-8343), which sounded up-front, tactile, and vivid—the last a word that would appear in my listening notes more than once in the days to come. The amp revealed good color and tension in the steady stream of eighth-notes in Leroy Vinnegar's double-bass line in "Who's Got Rhythm"—especially in his solo, after Mulligan's own solo on baritone sax—and it did a sufficiently fine job of detail retrieval that an off-mike shout at 1:17 really caught me off guard. As far as tonal color and textural richness were concerned, the experience of hearing Mulligan and Webster play duets in "Chelsea Bridge" and "Tell Me When" was nothing short of exquisite.

With mono and stereo recordings alike, the Raven amp sounded just a bit more hi-fi than my Shindo Corton-Charlemagne monoblocks, given the Spirit's crisper bass and more extended treble range. Regarding the latter quality, the Spirit sounded less sweet and, consequently, slightly less forgiving than the Shindos with recordings that tend to be grainy or bright. Although it might have been the psychoacoustic effect of moving to an amp with a wider frequency range, the Raven made some instruments sound a little less meaty than I'm used to hearing, as in the various percussion sounds—drumsticks clacked together, a very small crash cymbal struck with varying degrees of force, etc.—appearing in the surprisingly uncompressed "That Would Be Something," from Paul McCartney's McCartney (LP, Apple PCS 7102). Nevertheless, the Raven had a really impressive way with timbral colors, as it demonstrated with recordings such as the Electric Recording Company's new reissue of a performance of Beethoven's Violin Concerto by soloist Leonid Kogan, with Constantin Silvestri conducting the Paris Conservatoire Orchestra (mono LP, EMI/Electric Recording Company SAX 2386).

Solo-piano recordings seemed to most benefit from the Raven Spirit's very wide frequency range—that, and the amp's very good sense of touch and apparent freedom from distortions of timing and pitch. Wilhelm Kempff's distinctly smooth, flowing, yet articulate approach to the Prelude and Fugue in e from Book I of J.S. Bach's The Well-Tempered Clavier (LP, Deutsche Grammophon 2531 299) was spellbinding through the Raven Spirit, as was Glenn Gould's deliberate yet more dynamically nuanced performance of the Prelude and Fugue in g, also from Book I (LP, Columbia MS 6776), and Gould's less clanky recordings of various of Bach's French Suites (LP, Columbia Masterworks M 32347). In these and other good piano recordings, the Raven allowed the instruments an appropriate warmth and body without a pitch-obscuring excess of same. With both my Altec Valencias and the enduringly wonderful DeVore Fidelity Orangutan O/96 speakers, the Raven sounded more than adequately powerful, the music maintaining its poise throughout the peaks.

The Raven's spatial performance suited me just fine—which is to say, it stressed presence, substance, and scale over the sort of airy, overarticulated spaciousness that some listeners enjoy but that, to me, just sounds fussy and unreal. On Dame Janet Baker's recording, with Bernard Keefe and the Melos Ensemble of London, of Ravel's Poèmes de Stéphane Mallarmé, (LP, L'Oiseau-Lyre SOL 298), the Raven gave a very good, believable sense of the spatial perspectives between Baker's very upfront voice—the Raven pulled her much farther forward than do my Shindo Corton-Charlemagnes—and the flutes, clarinets, strings, and piano behind her (and, crazily enough, provided a notably realistic sense of height). Incidentally, as with the piano recordings noted above, vocal peaks were reproduced without a hint of strain.

Conclusions
By the time I got the Raven amp—any Raven amp—up and running in my system, I was eight kinds of cranky; notwithstanding the need for the neutrality of professionalism, one might understand if I'd been slightly, subconsciously prejudiced against the thing. Add to that a left-channel hum that never went away, and the sort of overcooked styling (and overdone mass) that contribute nothing to the sound, and you have a formula for mild irritation.

To the contrary, that the sound of Raven Audio's Spirit 300B Reference Stereo so thoroughly impressed me speaks more loudly than usual of the product's innate quality. This is a very good-sounding, musically exciting amp: up-front and very vivid, with detail and forcefulness tied together in a manner more than typically suggestive of real musical sound.

I put it to you as I'd put it to any friend: I think the design of this amp is exceptional, but the builder hasn't quite got his act together. But he may not be far off the mark, and for that, I'd keep an open mind and be prepared to give the Raven Spirit another chance in the not-too-distant future.