Author Topic: Adcom GFA535II stereo power amp  (Read 1116 times)

Offline Andile

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Adcom GFA535II stereo power amp
« on: October 19, 2018, 08:42:03 PM »
Description : Adcom GFA535II stereo amplifier in great condition,  two separate power supplies,  dual mono designed by Nelson Pass. 60W x2, built like a tank, quite heavy for its size.

Location : Pretoria East
Shipping : At buyer's expense and risk
Price : R2800

Please pm me if interested

Actual pics



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Offline Andile

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Re: Adcom GFA535II stereo power amp
« Reply #1 on: October 20, 2018, 06:20:00 PM »
I forgot to mention that this is a Great F...... Amp!!

Offline Andile

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Re: Adcom GFA535II stereo power amp
« Reply #2 on: October 23, 2018, 06:39:27 AM »
Still available  :groovy:

Online fdlsys

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Re: Adcom GFA535II stereo power amp
« Reply #3 on: October 23, 2018, 01:02:50 PM »
Quote
Description : Adcom GFA535II stereo amplifier in great condition,  two separate power supplies,  dual mono designed by Nelson Pass. 60W x2, built like a tank, quite heavy for its size.

Nelson Pass designed only one Adcom amp, the GFA555. Not the 535 and definitely none of the "Mk2" versions which are apparently quite different from his original.

For reference, his own words:
https://www.diyaudio.com/forums/solid-state/5280-adcom-555ii-nelson-pass-post51749.html
The four building blocks of the universe are fire, water, gravel and vinyl. Dave Barry
Come back when you’ve lived a little. Miles Davis

Offline Tzs503gp

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Re: Adcom GFA535II stereo power amp
« Reply #4 on: October 24, 2018, 08:47:46 AM »
A lot of respect for the poster djk, two posts down from Nelson Pass. Tells Mr. Pass exactly what was wrong with his design, and what was done to fix it.
Not many okes in that category.

Offline Agaton Sax

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Re: Adcom GFA535II stereo power amp
« Reply #5 on: October 24, 2018, 09:05:17 AM »
A lot of respect for the poster djk, two posts down from Nelson Pass. Tells Mr. Pass exactly what was wrong with his design, and what was done to fix it.
Not many okes in that category.

djk was an extremely knowledgeable guy posting mainly on horn issues. To say he pointed out problems with Pass' design would be doing disservice to two greats. djk pointed out how Adcom screwed up the Pass design. Nothing new there - Dennesen screwed up a great John Curl design with unauthorised parts substitutions  in their supposedly fabulous but still great JC 80 too.

Online fdlsys

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Re: Adcom GFA535II stereo power amp
« Reply #6 on: October 24, 2018, 10:16:56 AM »
djk was an extremely knowledgeable guy posting mainly on horn issues. To say he pointed out problems with Pass' design would be doing disservice to two greats. djk pointed out how Adcom screwed up the Pass design. Nothing new there - Dennesen screwed up a great John Curl design with unauthorised parts substitutions  in their supposedly fabulous but still great JC 80 too.
+1
Nelson replied to DJK a few posts down: "Funny you should mention. The original 555 had 15030's and 31's, as I recall. "
So, yes - Adcom was riding on the Pass design concept for decades, spawning all sorts of "clones" but instead of sticking to the original they decided to chop & change - not very successfully.

BTW, bypassing PSU EL caps is done routinely in DIY, sometimes meaningfully, often not.
But, it is pretty much never done by middle-of-the-road equipment manufacturers simply because PP bypass caps of that size would cost as much - if not more - as all EL caps in the PSU!

The rest of the comments: using NTC resistor to limit the inrush current, relays, (un)related power switch life expectancy ... that's not part of the circuit design, but a matter of implementation of the circuit; amp build.
The four building blocks of the universe are fire, water, gravel and vinyl. Dave Barry
Come back when you’ve lived a little. Miles Davis

Offline Andile

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Re: Adcom GFA535II stereo power amp
« Reply #7 on: October 25, 2018, 06:43:48 PM »
First and only price drop!

R2600

Offline Andile

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Re: Adcom GFA535II stereo power amp
« Reply #8 on: October 28, 2018, 09:55:54 AM »
R2600

Offline Andile

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Re: Adcom GFA535II stereo power amp
« Reply #9 on: October 31, 2018, 08:05:53 AM »
Bump

Offline Andile

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Re: Adcom GFA535II stereo power amp
« Reply #10 on: November 01, 2018, 07:00:58 PM »
R2000 only for today :groovy:

Offline Andile

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Re: Adcom GFA535II stereo power amp
« Reply #11 on: November 16, 2018, 08:19:33 AM »
Still available  :groovy: