Lacee, thanks for bringing up the little 20W NAD . . . this is the perfect 1980s equivalent of the Phase Linear amps. I serviced these back in the day, and even had the "Power Envelope" decendent (3225PE?) as a test-bench amplifier for several years. In contrast to the big, "all technical" 1970s aesthetic, it was small, lightweight, low-powered, and simple-looking. But like the Phase Linear, it was cheaply made and unreliable . . . and the sonic signiture was filled with exactly the opposite types of problems.
I will say that the preamp sections were pretty decent, maybe even good considering the low price . . . but the power-amp section was an absolutely atrocious piece of engineering. The key "feature" was that it didn't have emitter resistors on the output transistors, and I assume that this was an attempt to reduce notch distortion. But even if this had been a good idea (which it wasn't) . . . they then chose the absolutely cheapeast big power transistors available (2N3055/MJ2955) that have poor linearity even by 1970s standards. The result is that even with enough idle current to make it run pretty toasty, it was still really operating in underbiased Class B, and put out a whole slew of nasty harmonic and intermodulation distortion products. This may have been "redeemed" somewhat by the single-transistor input stage, which guaranteed a big helping of even-order distortion as a big sugary coating for that rancid-piece-of-meat of an output stage.
I will say that the preamp sections were pretty decent, maybe even good considering the low price . . . but the power-amp section was an absolutely atrocious piece of engineering. The key "feature" was that it didn't have emitter resistors on the output transistors, and I assume that this was an attempt to reduce notch distortion. But even if this had been a good idea (which it wasn't) . . . they then chose the absolutely cheapeast big power transistors available (2N3055/MJ2955) that have poor linearity even by 1970s standards. The result is that even with enough idle current to make it run pretty toasty, it was still really operating in underbiased Class B, and put out a whole slew of nasty harmonic and intermodulation distortion products. This may have been "redeemed" somewhat by the single-transistor input stage, which guaranteed a big helping of even-order distortion as a big sugary coating for that rancid-piece-of-meat of an output stage.
Not as good or as pleasing a sound as the tube stuff, but still better than the solid state amps I had been using in the 1970s.Well, selective memory seems to work both ways . . . we overwhelmingly shun what was in vogue in some eras, and romanticize others. One of the reasons why I mentioned the 1970s B&O receivers was because (like the NAD amps of the 1980s) they offered a modestly-powered, domestically sensible alternative to the "high knob-per-dollar" mainstream aesthetic. They were vastly better engineered than either the Phase Linear or the NAD, but had a few quirks of their own (esp. cultural?) . . . I'm wondering whether they're remembered similarly to some of the more high-profile [sic] pieces of the decade.
This is the reason I find the new fascination for 70's solid state stuff so perplexing.
From someone who was there and listened to that stuff when it was new and all the rage, and then moving on to better things,I just can't see the interest in any of it.