I haven't been pleased by Audio Research amplification for a very long time, and that dissatisfaction only mushroomed over the past dozen years or so. Keep in mind I've sold and owned ARC in the distant past. I'm long out of the industry. I've cited ARC as tragic evidence that hifi took a wrong turn, continuing to release products built more for ego than music. The entire REF line has sounded so far just about as far removed from convincing musicality as one can get using vacuum tubes, so I had hopes that the REF 75, being a modest implementation of a simpler, rethought ARC sound, might reverse their long slide into toneless asceticism.
I guess not. I heard the REF 75/ Wilson combination, and every other ARC installation at the show. I suppose one can get so accustomed to that sound so as to interpret it as "grainless" if all other comparisons are to amps that have more grain, but that's not what I heard. In fact, one of the distinguishing "features" of every modern ARC tube amp I've heard (and I've heard just about all of them) is the pervasiveness and persistence of distracting sonic grain. I'll go further and say there's midrange grunge, too, as in the subtle crossover notch grit common to all push-pull tube amps voiced to sound like solid state and tilted to over-resolution. Another common "feature" of the REF series, including this new one, is spatial "field flattening" and vocal glare. But again, if all you listen to are amps that are worse in these respects, the REF might be heard as smooth and articulate.
Not to me.
Some of this is surely the fault of current production tetrodes and pentodes, but some of it originates in design. The REF 75 sounded tonally bleached, with incomplete note decay. It was revealing of leading edge detail and very competent with hard-but-not-harsh sounds like single-event percussives and strong string plucks. It lost the rest of the note too soon. many simultaneous transient events didn't put the amp in a good light. Unless congestion upon crescendo sounds normal to you. And I don't forgive it insufficient break-in time because these same traits are exhibited by every other REF amp in the series as well.
The svelte Audience solid state amp was better in all these respects and I say that as someone who has never had a single year of my life without tube amps amplifying music for me. The McIntosh autoformer SS amps are more musically convincing. And lots of non-mainstream tube amps will trample the REF 75 if you're judging by musical performance instead of wanting to listen to square waves.
I'll say one thing in the ARC's defense. Most of the "name" tube amps of substantial power at the show were lashed to crossover-intensive multi-driver speakers, so on top of the compromises in the amps, you were listening to compression and subtle grunge at the crossover points of the speakers. The two together aren't a recipe for convincing music reproduction, but they're certainly a recipe for something....else.
The REF 75 wasn't nearly the only disappointment at the Newport Show, but it was one of the more egregious let downs.
Phil