How do we remember 1970s amplifiers?

I have a mint Phase Linear 400 Series 2, in which I installed DC protection circuitry a couple of years ago. I have all new electrolytic caps waiting to do a total recap, I just haven't gotten around to it yet. To my ears, it is not a bad amp at all. Not the finest, but better in some ways than some other amps of that era that I've had in my collection.

Lacee, you're probably right that I was a bit too harsh on the 3020 . . . NAD's manufacturing quality steadily declined through the 1980s, then plummeted under the ownership of KH America in the early-1990s . . . and this is when I serviced them. It seemed that the late-1980s stuff failed at least twice as often as that from the early-1980s, even though they were newer. The current product of the time (I'm thinking of the 505 and 705) had out-of-box failure rates of at least 25%.

The 3020 was indeed cheap and it did have a nice phono preamp, this was probably the best part. And after two failures in two years with my 3225PE bench amp, I added a pair of 0.33-ohm emitter resistors and switched to 2SC3281/2SA1302 output transistors, then re-biased. It completely transformed the performance . . . the distortion was reduced by something like 75% leaving overwhelmingly even-order products. The little NAD then sounded quite nice with my KEF C25 bench speakers . . . which I guess was exactly the kind of setup for which it was intended.

Still, I don't know whether to praise the design because it didn't take many changes to make it a nice little amp, or to be really annoyed because these changes would have cost less than $2.00 per unit in production . . . probably cheaper if you factor in volume pricing of the day and the better reliability during the warranty period. With the Phase Linear 700 it was far more clear-cut -- the circuit was wholly unsalvageable. The best thing for one of these is to use the case and heatsinks (but NOT the transformer) for a project amp.

Kirkus, do you design gear? Seems like you know a lot about it.

My AR receiver gave me many years of joy, but the sound is only in my imagination now. I was seventeen; it was a very good year...

Mostly I remember my speakers (Kef) and 'tables (several). My only memorable electronics were SS models from Audire - the Diffet pre and a power amp which I can't recall the model designation of. Purchased cheap at Crazy Eddie, a large New York discount chain that somehow got the Audire line.

IIRC, they sounded quite good. Of course, that's a damn big "IF" in the IIRC. Not too much later I bought a pair of the earliest production Quicksilver mono amps which - I think - were simply great amps (of their type).

Marty