Hovland Sapphire power amplifier Page 2
Switch the Sapphire on from its side-mounted switch and the blue light show begins. After a short warmup, you check the bias using the meter mounted on the top plate. Hovland uses a unique adjustment scheme featuring an idle-current attenuator and a balance pot for each channel. Using a screwdriver to flip through the five-position bias switch ("Off" plus one for each tube), you note the meter position for each. Ideally, it should be centered for each tube. The precise procedure involves setting for sufficient current and balancing each channel's pair of tubes.
Once you get the hang of it, setting the bias is not difficult—unless, as I experienced, one of the tubes is bad out of the box. Then, a great deal of confusion occurs, because getting the bias correct and balanced between the two tubes is almost impossible. Hovland assured me that my experience was "unique." I don't doubt it. Once I'd been sent a replacement pair, setting the bias was easy, and it didn't drift during the two months I had the Sapphire for review.
Judging by the many nights I happily spent listening to—luxuriating in—the Sapphire's sound into the wee hours, I'd say this was one of the best-balanced amplifiers I've heard.
If the recently reviewed (December 2001) Kora Cosmos monoblocks, another enjoyable listen, were on the fast, lean side of the tube amp continuum, and had me wishing for more generosity on bottom, the Sapphire turned out to be on the full-figured side. That's not to say it was "slow" or "warm" or "soft," for it wasn't. It did sound "rich," however, and not the best match for the Amati Homage, which has a similar personality. Its sound was far more complementary to the Audio Physic Avanti III's fast, detailed, more linear presentation—a combo many HE2001 attendees heard in one of the Sound by Singer rooms. I also found that the fast, detailed Discovery Cable Essence interconnects and speaker cables were a better match than the combo of Harmonic Technology Pro Silway II interconnects and Magic Woofer speaker cables, though they, too, worked well.
I could never confuse the Sapphire's slightly underdamped but well-defined and powerful bass presentation with that of a solid-state amplifier, but, perhaps because of its hybrid nature, the amp's bass never sounded flabby. It did sound full, though, and well-fleshed-out on the bottom.
That lush, full-bodied sound extended right to the very top, giving the amp a solid, seamless, harmonically generous presentation that for the most part seemed complete, and nearly ideal. In the end, though, I concluded that the Sapphire lacked the last word in air, ambience, and openness that the Koras possessed (though the Koras' bass leanness was instantly noticeable). I say "in the end" because the Sapphire's balance was so cannily crafted that I didn't notice what was missing until I reinserted my reference Musical Fidelity Nu-Vista 300, which, while adding air and ambience, sounded positively bleached-out harmonically by comparison—until my ears adjusted to its leaner but equally beguiling presentation.
I don't mean to suggest that the Sapphire sounded closed-in or dull. It didn't—its portrayal of high-frequency transients was naturally "fast" and detailed. Nor did it sparkle or shimmer—qualities I can live without, especially when compensated for, as by the Sapphire, with an extremely impressive and unusually effective expression of instrumental solidity and weight without bloat or thuddiness. The Sapphire was always inviting, always compelling, and never boring—something dull- or slow-sounding amplifiers always are, once you get beyond their usually attractive midband richness.
On Tony Bennett at Carnegie Hall (LP, Columbia C2S 823), I found the images of Bennett's voice and the orchestra behind him more full-bodied and impressively solid than I was accustomed to with this recording. There was more "there" there, but the presentation seemed to move me closer to the stage than I was used to—something I usually associate more with brightness than with weight. The handclaps also sounded and felt more like flesh and less like rain on a tin roof. But I felt that there was less hall ambience apparent, and a lessening of soundstage depth. Those last two qualities were less noticeable when I was just listening for fun, which is what I did the few weeks I had the Sapphire in my system.
Though the Sapphire's presentation of depth and spaciousness was somewhat limited compared both to the Musical Fidelity and to many other amplifiers I've reviewed, it excelled at distinguishing instrumental lines occurring in the same tonal space—something the far less expensive ($2250) Smart Devices 2X150VT tube/MOSFET hybrid power amplifier, which I reviewed in January 2001, was noticeably unable to do. I cited The Band's second album, The Band, as an example: "The Band's second album, The Band, is a very warm recording with a high concentration of low-frequency energy created by a vintage drum kit with a flabby bass drum, tuba, electric bass, and, on many tracks, the acoustic confines of Sammy Davis, Jr.'s cabaña, which the group had converted into a recording studio."
Separating out those instrumental lines and preserving the distinct sonic fingerprint of each while delineating the physical space in which the music-making occurs is a difficult task for any amplifier. Leaner-sounding amps like the Nu-Vista 300 or Herron M-150 usually have an easier time of it, while warmer ones like the Sapphire tend to mush things together. The Sapphire managed to effectively separate the lines while maintaining each instrument's full, rich harmonic personality. The Herron did equally well at uncovering and separating the lines, but did so by shining on the sound picture an aural flashlight, which tended to somewhat brighten and thin the harmonic structure.
The more I listened to the Sapphire, the more I appreciated and enjoyed its velvety yet detailed overall presentation. On certain vinyl reissues from Classic Records that I felt leaned toward a thin sound, the Sapphire seemed to flesh out both the harmonics and the textural details. For instance, I've always felt that the reissue of Tchaikovsky's Symphony 6, the "Pathétique," with Pierre Monteux and the Boston Symphony (RCA/Classic LSC-1901), was one of Classic's better efforts. It never sounded brighter than the original, just somewhat thinner, more skeletal. The Sapphire seemed to restore missing weight, body, and harmonics. Yet when I played an original pressing, it didn't sound thick, syrupy, or overcooked—original and reissue sounded much more alike than I remembered.