Masterpiece!

I started off by saying that it wasn’t the individual virtues of the 610T but their synergy that makes the amp so special, because what all of these things add up to— the improvements in neutrality, coloration, imaging, resolution, transient response, power delivery, action, and staging—are a huge improvement in transparency to the source. By this I mean that the 610T imposes less of its own signature on whatever LP or CD it is playing, and in reducing its own signature reduces our sense of listening to and through an electromechanical chain of hardware. I’ve always felt that the first obligation of any piece of stereo equipment is to disappear as a sound source. The 610T does this to an extent I’ve never before experienced with an amplifier. For the most part, it simply lets you forget you’re listening to a hi-fi.

Oh, there are still a few areas where the 610T reminds you that it’s there. For one, it is consistently a little forward sounding, starting its imaging nearer to the plane of the speakers, rather than deep behind them. For another, as good as the 610T is in the treble, you cannot listen to it in comparison to a great solid-state amp like, say, the GamuT DI 150, and honestly say that it has all of the top-octave speed, focus, and detail that make something like the piano on the truly superb Decca Headline recording Mr. John Cage’s Prepared Piano so uncannily like a virtual choir of cymbals, bells, and drums. Through the 610T, all these sounds will be somewhat more relaxed, more gemütlich. (Paradoxically, this isn’t as true of the low bass, where the ARC will reproduce ostinatos like the deep cello and doublebass pizzicatos at the start of the Passacaglia of the aforementioned Lutoslawski Concerto for Orchestra with precise pitch definition and astonishingly realistic air and speed.)
 

Conclusion

The Audio Research 610T is the best high-powered tube amp I’ve heard in thirtyfive- plus years of listening. It is, to date at least, the greatest achievement of William Z. Johnson, whose long, legendary career as the chief designer and moving force behind the Audio Research Corporation is spangled with great achievements. For those with the kind of money and space and ancillaries that the 610T demands, I cannot recommend it highly enough. For the rest of us, it is something to dream about. If ever I’ve heard an amplifier worthy of being called “reference,” the 610T is it.