Amps from the 1980's -- What gear holds up sonically? Reliably?


Hi Everyone,

For me, the 1980s were a real "golden age" of amplifiers. Dr. Leach’s paper on building a low TIM amplifier had been widely distributed and relied on by budding designers, and lots of boutique brands came. It was also the era of the biggest of the Conrad Johsnon tube amps as well and the invention of the MOSFET.

For me, brands I cared about:

  • Threshold
  • Sumo
  • Perreaux (New Zealand, very pretty)
  • Tandberg
  • Hitachi
  • Kyocera
  • Nikko
  • Krell (of course)
  • CJ
  • ARC
  • Yamaha (professional)
  • Carver
  • Mark Levinson
  • Amber 
  • Tandberg
This was also the speaker era of Snell and Apogee and Martin Logan. I am not sure there would be a Krell today if it wasn't for Apogee's 1 ohm speakers.

I’m curious who is still listening to these vintage pieces, and which brands you think have stood up both in terms of reliability and / or sonics ?
erik_squires
Thanks to all of the contributors so far, this has turned out to be a great thread. I appreciate hearing about all of the experiences and especially about gear I never heard or saw myself.

I want to take a moment to acknowledge that our pleasure, our hobby, our interest and the industry has been advanced by people like the late Dr. Marshall Leach Jr. as well as others who researched, studied and shared their work with a needy/greedy audience.

Dr. Leach’s paper in 1976 was, I believe, a turning point and fuse lighter for the solid state amplifier market. Our hobby and expectations and the quality of products we can afford to buy would most likely be something entirely different without that paper and without his work. Certainly, many manufacturers took advantage of his proposal almost verbatim. If you understood his paper, you can read almost any amplifier schematic for the next 20 years before Class D amps came to the fore and identify each section in it.

His paper was at the same time a recipe and a challenge. It said "Here is how you make a good amplifier" and at the same time "See if you can make something even better." Engineers no longer had to hunt in the dark and search for the secrets to good solid state amps. All the parts and their use were laid out before them, while at the same time opportunities to improve upon and leave their own marks upon the discipline also opened up.

I should also point out that designers like Nelson Pass have long taken a different approach, and looked to simplify as opposed to enhance or perfect. And we are grateful for that approach as well! But when Nelson looks to simplify or others to re-think components they are constantly challenged by the Leach legacy. We can’t just remove sections, or alter feed back circuits. We must do so AND get sound as good if not better by doing so. Dr. Leach left a clear foil and challenge for others to take up, and improve upon. This is how progress gets done. We can say "Oh, amp X is nothing like the Leach paper..." but it is impossible to say these amps were not informed and challenged by it.

I should point out and thank Nelson Pass as he is quite active in the DIY community, sharing his thoughts, and tinkering "out loud" for the benefit of this community.

So, to people like Nelson pass as well as the late Dr. Leach, and the universities which create environments so students can learn from people like him, I would like to offer a heart-felt thank you. They enabled the industry, the hobby and ultimately the music.

Best,

E
I would certainly add Audire to this list, at least everything built after the Model 2 amp and Legato preamp. The Legato is reliable, but I wonder about the people who rave about its sound. It is certainly clean , but it's power supply limits its dynamics beyond belief compared to newer models, i.e. Diffet 3, 5 and Andante. I even preferred the bulky Diffet1. The Diffet 2 is also very good, but it was designed before CD's and before Julius built his speakers for testing. As such, it is a little loosey goosey in the bass, compared to the others. FYI, there is no Diffet 4, nor an amp using a 4 in the model number. Instead, the early amp was nalled the Forte", because so much of his equipment went to Japan, where the number 4 is considered to be like our 13. After this, Julius continued the use of musical terms.
Wow! the NAD  Amp where my choice for sure back then i had a 2600 and a 7600 bridged 

 i still have them but now I've moved up to the S 100 pre/amp and a pair of S200 running my  Polk audio SDA1.2 Flagships 
I'm surprised I only see one reference to Hafler.  I bought the 220 kit model I believe for $400 and for the day, it was an amazing amp.   I doubt anything came close to it in quality for that price.  Not sure how it would hold up today but back then, I loved them with my ADS 810's and M&K subwoooofer
I have to say, that my old Sumo Nine took on all comers in my system,  I've had some very well respected amps in there... to be fair,  my old Sumo was hardly a Sumo any more,  it had a radically superior part upgrades throughout...  from the power supply to the boards to the wiring.. So probably not fair... It is getting upgraded again this minute with Newer, higher voltage, higher mfd and lower esr supply caps now as well as a minor circuit change with all new Higher quality output transistors.  I'm excited to get it back.  I've always been told that the 2SC1831 could not be replaced.