McIntosh MC2102 power amplifier Page 3
As did the MC2000, the MC2102 uses four KT88 output tubes per channel, the tubes made for McIntosh by Svetlana, of St. Petersburg, Russia, Marina's home town. (I've never been inside, but the exterior of the huge, sprawling, Stalinesque factory looks like a prison.) The MC2102 is rated at 100Wpc into 8, 4, or 2 ohms, compared to 135Wpc for the MC2000.
"You can substitute 6550s with no measurable change in performance," said Larry. "The 6550s do not give you any less power."
Rectification is solid-state. Thermistors cushion the output tubes from the shock of turn-on. Bias is set by the factory—no user adjustments are needed, even when changing output tubes, according to Larry.
Based on what McIntosh has told me about some of the output tubes they've measured, I'd be cautious about tube rolling. I'd order any replacements directly from McIntosh. Nice to know, though, that you're not limited to KT88s. (McIntosh had nice things to say about the Sovtek KT88s they measured, too.)
When you run "balanced" from preamp to power amp, an extra input stage receives the balanced signal. One section of a 12AX7A tube is a cathode follower that passes the positive-phase signal; the other section inverts the negative phase signal. The two outputs are summed and fed to the input/phase-inverter stage. McIntosh claims common-mode noise rejection of greater than 60dB at mid-frequencies.
Because their new C2200 tube preamp won't be ready until fall, McIntosh provided their solid-state C42 preamp for my listening tests. This was the same model I'd used when evaluating the MC2000 Commemorative Edition (Stereophile, November 1999). I also used my Purest Sound Systems Model 500 passive preamp.
Speakers were the Triangle Antal XS, Verity Audio Parsifal Encore, B&W CDM9NT, Audio Physic Spark, and McIntosh's own new LS320 stand-mounted monitors. I used the Cary CD-303, Rega Planet, and Jupiter CD players (all 2000 versions). For analog, I relied on my trusty AR ES-1 turntable, SME 309 tonearm, Shure Ultra 500 cartridge, and AcousTech PH-1 phono stage.
If I'd been immediately impressed by the MC2000—the detail, the definition, the vividness of the sound, the dynamics—I was less impressed—less blown away, at first—by the MC2102. I heard a less powerful, less dramatic amplifier, even though there's only a slight drop in power from the MC2000—from 135Wpc to 100Wpc. Bass was tighter with the MC2000, if memory serves me right. There seemed to be more dynamic headroom. None of this was surprising, considering the MC2000's beefier power supply and two power-supply transformers. The bigger amp simply produced a bigger sound: a deeper, wider soundstage and better dynamics. But I began to warm to the gentler, less immediately impressive, possibly less insistent sound of the MC2102.
Okay, I no longer had the MC2000 for a comparison. But the MC2102 had a "tube magic" that the bigger amplifier hadn't quite had. For me. This remained true no matter what speakers I used.
The MC2102 produced a slightly softer, gentler sound—less dynamic, less dramatic, but easier on the ear. My ears, anyway. The MC2000's harmonic presentation was vivid—again, if memory serves me. The MC2102 seemed more relaxed, less brightly lit, less "Technicolor," as Jonathan Scull might say. I wasn't blown away, I was drawn in. Seduced.
I'm not suggesting that the MC2102 was rolled-off on the top end—it wasn't. Nor did I find its bass loose or soggy, in the manner of many tube amplifiers. The MC2102 gave me McIntosh bass: extended, tight, and above all, tuneful. The MC2102 transformed the Triangle Antal (slightly on the dry side of neutral, perhaps) into a warm, rich-sounding speaker. I got a similar result with the similarly voiced Audio Physic Spark...as well as a killer soundstage.
The MC2102 was stunning, too, with the B&W CDM9NT, controlling it well in the bottom end and bringing out the innate midrange sweetness of this most worthy speaker from Worthing. Good bottom-end control with the Verity Audio Parsifals—speakers that need some power to deliver their full-range performance.
McIntosh says that you need at least 100Wpc these days, what with modern full-range speakers and digital sources. Maybe they're right. I know I got good results using the Triangle Antal with the Sun Audio SV2A3. But I found myself using all 100Wpc of the McIntosh MC2102, according to those beautiful blue power-level meters.
At first I thought something might be amiss. Could I be using all that power? Then I read J-10's review of the McIntosh MC1201 amplifier in the March 2001 issue. As he noted, Mac power-level meters are different from meters that measure only voltage. Mac meters measure voltage and current, multiply them, and display the product as the real output in watts. What's more, the meters have a peak-hold feature that enables you to see for sure just where you're peaking out.