How do we remember 1970s amplifiers?

Lacee , so pleasant to read your comments, they are so parallel to my own. The store I worked at was a little place called Wack Electronics in Milwaukee Wisconsin-from 1975 to about 1977-then to a sound contractor, then back to the store until I became a rep in 1980. You are right about the tube stuff, it WAS better even then. (McIntosh too, but I wasn't a dealer) As a rep, I reprsented Jon Dahlquist, NAD, the folks at Crown, and Joe Grado- Proton too when it arrived. It was quite a time in hifi, I was a little late to party, there was so much business, so many hobbyists buying stereos in the 70s. By 1980 it was changing, rack systems where coming to big box stores, reel to reel was fading as Nakamichi took off. I so remember that Advent cassette recorder! There many very nice people in high end hi fi in those days, I think its still this way.

A DC300 in 1975 was a different beast compared to the competition than in 1980. Flame Linears in 1978 or so where the first company to meet the "dollar per watt" ideal, and at 399, the best bargain going. But boy they didn;t like to messed with. Crowns would work and work. But on something like an electrostat? Yuck! The Audio Research was smooth as could be.

NAD< what wonderful stuff in the time of the 3020, the 7020. That stuff STILL sounds good. A NAD 3020 and pair of little Fried speakers was fantastic

I eventually got more into pro, learning about live sound and installed sound where Crown eventually migrated when hi fi dried up. By the 90s it seemed high end hi fi stores where reduced to one per 1M market. "Listening to records" was no longer the cool hobby!

By the way, I just bought a Stromberg Carlson 1939 AM tube radio I found on ebay, with the acoustical labyrinth system, the very first transmission line bass system. VIntage Hi FI is still just as cool as it was new!

Alot of the collectable 70s pioneer/sansui mega receivers have an overly bass dominant sound...some would say 'tubby' quality...far from nuetral but kinda fun in a muscle car way...I didn't come into my own till the early 80s...when luxman and hk still made decent stuff...the hard part was finding good 2 way monitors ala BBC types...which are far more readily available today...but from a purely cosmetic and build quality standpoint...the vintage stuff has some merits...this is a crude generalization...but the low to moderate power offerings always seemed to perform better...the 70s amps listed above didn't hit my radar still much later...

Pubul57, aside from tons of repair and modification, my audio design experience revolves mostly around small-volume or one-off custom stuff for pro audio applications . . . various iterations of analog and mixed-signal "preamp"-type stuff. This has included mic preamps, electronic crossovers, long-line drivers and receivers, active bandwidth-limiting filters, small low-noise mixers, etc. etc., and various combinations of these building blocks combined into a single chassis. I used to get a lot of requests like "We need these PA systems to be at least 8dB quieter at the inputs to the mid- and tweet-amps, and get rid of that 'clippy sound' in the bass when it's really loud. Can you build something to do that?" And I would . . . and all kinds of similar stuff in FM broadcast and recording.

But I'm not an EE - my education is in classical music, and the way we learned about harmony, part-writing, counterpoint, form, etc. was to study the works of the masters (and the also-rans, too). I tend to take this approach to the study of audio design . . . since it's much more informative to analyze the harmony in Schumann's "Ich grolle nicht" than a silly textbook example, I'd rather listen to i.e. a DC-300 or whatever, then measure it and study its circuit design, than simply read about hypothetical circuits (and equations simply for their own sake) in a typical undergraduate EE text. The repair process is a natural method for analysis and measurement, and since I like to listen to music while I work . . . I've always kept a well-set-up amp/speaker system on my test bench, so I'm always trying to correlate what I hear to what I see and measure.

And I'm also generally a sucker for history, and love hearing/reading people's stories and narratives . . . hence this thread. Again, thanks to all for the contributions!

I had fun building the hafler pre and power amp kits;dh101 and the dh500 power amp.At this time of my early audio hobby the dh500 I thought was just awesome and produced the best sound driving my infinity speakers;the 500 still surfaces now and then with mods from musical concepts;
it was a pretty good performer for its time.

The DynaKit 120 circuit is a preamp on steroids. Output through a big capacitor: no transformer. Its sound quality was critisized until they come out with the conventional 150, which made the 120 sound good. I had both.

The Kenwood L-07M is a direct-coupled amp, input to output. It is really an analog-programmable DC power supply, with response time fast enough to play music. Response is DC to 100KHz. You have never heard bass until you try the L-07M.