Jeff Rowland Design Group Model 2 power amplifier
The memory of that conversation came back to me after a recent chat with another audiophile, who had heard that I had a Rowland (footnote 1) Model 2 for review and asked me if I didn't think the Rowland was too expensive for its power output. The Stereophile Reviewer's Oath made me bite my tongue—the Oath has been responsible for a lot of chewed-up tongues—and I told him that he'd just have to wait for the published review to find out what I think of the Rowland Model 2.
How do you define value in an audio component? For an amplifier, power output is obviously important, but it's not the only criterion; otherwise, we'd all be selecting our amplifiers strictly by price:watt ratios. The Rowland Model 2's $5800 for 75W puts it above the 95th percentile of amplifier price:watt ratios (footnote 2), although it's the least expensive amplifier from Rowland. Is it worth the money? Can you get sound that's as good or better from amplifiers that cost much less? Is this review going to provide the answers, or are these merely rhetorical questions?
Description & design
Smallish, very heavy for its size, with classic proportions, and impeccably finished. Beauty, of course, is in the eye of the beholder, but in this beholder's eye, the Rowland Model 2 is one beautiful piece of equipment. Everything about it says quality. All chassis components, including the ¾"-thick front panel, are made of machined aluminum alloy; fit'n'finish are second to none. Dimensional accuracies are said to be held to within 0.005" tolerance; dimensional ratios are designed to be "golden mean" nondivisible, and the size of each cooling fin is non-harmonically related to the adjacent fin.
The construction of the Model 2 reveals an almost fanatical devotion to resonance control. The two toroidal power transformers are enclosed within a machined-aluminum tube, which is physically isolated via large Neoprene O-rings and sandwiched between two machined subchassis structures spanning the entire length of the amplifier. Power-supply capacitors are rigidly clamped to the subchassis. The critical audio circuitry is contained in plug-in potted modules, which are themselves clamped in place by aluminum bars. The top panel fits the chassis exactly and is held firmly in place by a set of bolts/washers.
Finally, Rowland provides both machined metal cones and Sorbothane discs for a choice of coupling or decoupling support. (I used the metal cones.) The effect of all this resonance control is obvious when you tap or knock on the amplifier: all you get is a very dull thud (and sore knuckles).
Both the front and the rear of the amplifier have clear, uncluttered layouts. The front panel has only an illuminated power button—no meters or flashing LEDs, thank you very much—which switches between Operate and Standby. The rear is dominated by a 1.5"-diameter fitting that looks as though it's for hooking up a central vac. In fact, it's the socket for the cable that will connect the Model 2 to the optional battery power supply (to be available this summer). The Model 2 has XLR balanced inputs only, but Rowland provides a neat pair of XLR-to-RCA adaptors; the Model 2 can be driven balanced or unbalanced. (Rowland follows the convention of having pin 3 on the XLR connector as positive so that comparisons with equipment having the more common, ANSI-standard, pin-2-positive assignment involved reversing the absolute phase to compensate.)
One toggle switch allows for selection of low-impedance (600 ohm) or high-impedance (36k ohm) operation; another the choice of 26dB or 32dB gain. I used the Model 2 with the high-impedance, low-gain settings. The rest of the space on the rear panel is taken up by a single pair of Cardas binding posts (they have enough clearance to allow biwiring), a socket for the optional remote control, an IEC 320 socket (for a heavy-duty 20 amp power cord), and an AC fuse.
Jeff Rowland was one of the first audio designers to tout the benefits of fully balanced (differential) circuitry; needless to say, the Model 2 is not one of those amps that has balanced inputs but whose circuit topology is actually unbalanced. A fully balanced design like Rowland's requires essentially double the components of an unbalanced design; this is undoubtedly part of the reason for the Model 2's cost. The circuit topology is of the current-feedback rather than the more common voltage-feedback type—an approach that, according to Rowland, offers wider bandwidth, very fast settling time, and low distortion at all frequencies.
Footnote 1: Thankfully, the Rowland Design Group is still headed by Jeff Rowland, so we don't have to go through that "Are we talking about the Man or the Corporation" nonsense (cf Mark Levinson, Carver).
Footnote 2: The percentile estimate is just a guess. I didn't plot a frequency distribution of price:watt ratios. After all, this is just an intro. Anyway, price:dBW ratios would be more meaningful but still misleading.