A case for warm (vintage) amplifiers

[audio_tony]

If anything, the 'warmth' attributed to vintage gear is more likely due to the paper cone tweeters often used at the time. These tweeters typically had a limited HF response and rolled off pretty quickly at the limit of their top end.

Dome tweeters (metal, cloth or otherwise) were typically only used in expensive speakers. I don't remember when their use became widespread in budget speakers.

 

[AJM1981]

All of the '70s amps I've tested are 'unvoiced'. Even the Aiwa micro amp I have is unvoiced. Same for the Mitsubishi gear I have and tested. The Yamahas from that era I have are unvoiced, despite the persistent urban legend that Yamaha Natural Sound components from that era are somehow distinguishable from other unvoiced amps. I also haven't heard any gear from that era that was significantly voiced, unless the tone controls or loudness switches were adjusted. Lots of us, fed up with the lack of audible voicing our amps had, warm or otherwise, opted for graphic equalizers. Or better speakers.

The mid-70s world of engineering was rooted for a heading towards digital (CD) as a new consumer medium. Digital audio was the 'buzz'. Quad (for example) went from tube amplifiers to solid state, with the introduction of the 303. Often been mentioned as a leap in consumer audio and ready for a new age. Solid state was a slow progress towards the 'readiness' for digital consumer media.

Sansui's line of amplifiers have different characteristics along that transitional way. They offcourse have always claimed to deliver perfect sound, but there was a gradual shift in how 'perfect sound' was perceived. Which is audible. If you connect the au111 (late 60s) and compare it to the au317 (late 70s) the characteristics are different. With everything in line between shifting gradually. I will leave it to those who measure and judge if they agree or not.

I don't think any hard claims are made by just indicating gradual shifts from analog on the way to a new age of digital consumer media and why the 70s were not the 60s.

 

[DSJR]

The mid-70s world of engineering was rooted for a heading towards digital (CD) as a new consumer medium. Digital audio was the 'buzz'. Quad (for example) went from tube amplifiers to solid state, with the introduction of the 303. Often been mentioned as a leap in consumer audio and ready for a new age. Solid state was a slow progress towards the 'readiness' for digital consumer media.

Sansui's line of amplifiers have different characteristics along that transitional way. They offcourse have always claimed to deliver perfect sound, but there was a gradual shift in how 'perfect sound' was perceived. Which is audible. If you connect the au111 (late 60s) and compare it to the au317 (late 70s) the characteristics are different. With everything in line between shifting gradually. I will leave it to those who measure and judge if they agree or not.

I don't think any hard claims are made by just indicating gradual shifts from analog on the way to a new age of digital consumer media and why the 70s were not the 60s.

When I once challenged the then Quad UK rep/sales manager about amps 'all' sounding the same, he claimed that all 'Quad' amps sounded the same, power output apart. They had a display case at a show once, with switch-box and headphones to switch between the II valve pair, a 303 and 405 I remember. Music was 'light' I recall and via the 'phones (maybe Stax, I can't remember now as it was decades ago), they did indeed all sound the same.

1970s solid state amps, even 'good' ones, had all distortion measurements bordering on the audible (with sinad surely in the 30s to 60s on some favoured expensive amp confections) and back then, even the Martin Colloms tests of the mid 80s when 'high end' became desirable for all manner of reasons and some younger yuppie-style fellas could afford to splash out on such gear (ARC, Krell, Levinson and so on into Apogee panels, which were fashionable back then).


Almost all amps from the 70s and early 80s, had sensitivities of a few hundred millivolts only and some with active line buffers before the volume pot could overload with the max 2V output of a CD player. This I think, still lingers as Amir has found when testing some integrated amps (I'm reminded of the Hegel review, which used increasingly out-dated gain structures internally, shown with the limited output of the 'preamp' output sockets)