Jeff Rowland Design Group Model 2 power amplifier Bob Deutsch December 1995
In my four years of doing equipment reviews for Stereophile, I've had in my listening room, for varying periods, tube amplifiers from Audio Research, Sonic Frontiers, Luxman, VTL, Cary, Audion, Conrad-Johnson, and Quicksilver. Some had the "magic" (tubeophiles will know what I mean) but were deficient in other ways: insufficient power to drive most speakers to realistic levels, weaknesses at the frequency extremes, etc. Others had lots of power and wideband frequency response, but were missing the magic.
What is this "magic"? Simply, it's the ability to avoid sounding like an amplifier, an absence of "electronic" sound...Of the solid-state amplifiers I've listened to at any length, the one I've found to have the least amplifier sound was the Rowland Model 2 (reviewed in Vol.18 No.8). This is the amp I used for explicit comparison with the Balanced Audio Technology VK-60.
Like the VK-60, the Rowland Model 2 is a fully balanced design, but it uses different XLR pin-assignment conventions (pin-3 positive for the Rowland, pin-2 positive for BAT), which means that the two amps' absolute polarity is reversed—a problem easily corrected by use of the Sonic Frontiers digital processor's polarity reversal feature. The Model 2's rated 75Wpc puts its power output just 1dB higher than the VK-60, and the $5800 price is correspondingly higher.
When I started the Rowland/BAT comparison, I hadn't listened to the Rowland Model 2 for at least a couple of months. Firing it up again, I was quickly reminded why I'd been so enthusiastic about this amplifier in the review. It is a truly excellent amplifier, worthy of Class A status. I required several back-and-forth changes between the Rowland Model 2 and the BAT VK-60 to identify their differences.
The comparison between the amplifiers confirmed that the VK-60 is quite special when it comes to harmonic accuracy. The Rowland Model 2 is no slouch in this area; in fact, its preservation of the natural timbre of instruments and voices outpoints any other solid-state amplifier of my experience. Still, whenever I switched over to the BAT VK-60 (matching levels, and remembering to reverse absolute polarity), a layer of artificiality was removed, and I came closer to feeling that I was listening to the real thing. Also, although the depth of the soundstage with the two amplifiers was comparable (with the right recordings, very deep), the VK-60 evinced superior three-dimensionality of images within the soundstage. Thus the trombone solo in "Winter Wonderland" (Big Band Basie, track 13) seemed to have a more rounded physical presence, and there was greater differentiation of the individual voices that make up the Turtle Creek Chorale in Postcards (Reference RR-61CD).
Well-designed solid-state amps tend to have better bass responses than tube amps; indeed, this was an area in which the Rowland Model 2 was superior to the BAT VK-60. However, the differences weren't as great as one might expect. With my usual torture-test, Mickey Hart's Planet Drum (Rykodisc RCD 10206), the bass from the VK-60 was actually quite impressive: deep and well-controlled, with perhaps just a bit of added warmth, but a far cry from the warm-and-woolly bass that characterizes so many tube amplifiers.
Only when I switched over to the Rowland Model 2 was I reminded that the Dunlavy SC-IVs are capable of even better extreme-low-end performance. For those with speakers whose bass responses doesn't go much below 30Hz, the point is academic. For those with speakers that have subwoofing capability and who like to play music that tests that capability, the Rowland Model 2 might well be a better choice.—Robert Deutsch