Adcom power amp

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C Moore
Posts: 1266
Joined: Mon Oct 22, 2007 9:28 am
Location: USA, California, 94585

Adcom power amp

Post by C Moore »

A friend gave me this old Power Amp.
He said one of the channels is "bad."
All I know is that it generates Positive and Negative 56VDC on both sides. Not even sure what you do with an amp like this. There is no gain control at all. Just has an On-Off switch.
I was just going to save the step-down toroid and see if anybody needs something like that. Then I was just going to gut the chassis and save it for a "project."
Is there any need to keep this guy alive.? As I said, I am not even sure what these do......a "fixed" power amp.?
Thank You

http://i111.photobucket.com/albums/n143 ... com002.jpg
http://i111.photobucket.com/albums/n143 ... com001.jpg
http://i111.photobucket.com/albums/n143 ... com003.jpg
diagrammatiks
Posts: 558
Joined: Sun Mar 27, 2011 12:28 am

Re: Adcom power amp

Post by diagrammatiks »

man adcoms are great amps.

might be worth getting it fixed if you need a hifi power amp.

you usually pair those with a preamp that has all the controls on it.

mine has 2 little trimmers for channel balance and that's it.
C Moore
Posts: 1266
Joined: Mon Oct 22, 2007 9:28 am
Location: USA, California, 94585

Re: Adcom power amp

Post by C Moore »

OK. guess I should have been able to figure that out.
So it just amplifies as much signal as it gets from a stereo pre.
At any rate.....I really have no use for this thing. But maybe I should take the opportunity to learn some SS trouble shooting.....if you can call my skills "trouble shooting". :)
Thanks
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Milkmansound
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Re: Adcom power amp

Post by Milkmansound »

Check the internal fuses on the speaker outputs. Very common "failure" with these amps.

I used to pull them out of the trash, fix the fuse, sell them on eBay and pay my rent :D
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rdjones
Posts: 818
Joined: Tue Aug 31, 2010 2:20 am
Location: Music City, TN

Re: Adcom power amp

Post by rdjones »

The older Adcoms are highly regarded in certain circles for studio monitor amps.
I wouldn't just gut it, someone will want it for parts if it's not working.

Search rec.audio.pro for comments about the GFA series.

rd
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Reeltarded
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Joined: Sat Feb 14, 2009 4:38 am
Location: GA USA

Re: Adcom power amp

Post by Reeltarded »

Great amp. Also a great amp for your amp on a load. I use a GFA 5.5. Same amp about two years newer.

I have one down too. If you throw it away, throw it at me! :p
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
passfan
Posts: 1353
Joined: Sun Jan 10, 2010 2:01 pm
Location: Central Florida

Re: Adcom power amp

Post by passfan »

Those type of amps are usually the rated output for 1 volt of input. If it's 25 watts at 8 ohms , that;s what you get if you plug a cd player straight in. As someone said earlier, you need a preamp or just wire a set of rca's to a 10k pot and use what we call a "passive pre". You have a good channel to compare to the broken one for troubleshooting and chances are unless you see something burnt , it could be something simple.
"It Happens"
Forrest Gump
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dobbhill
Posts: 434
Joined: Sat Jan 22, 2005 12:04 am
Location: Louisiana

Re: Adcom power amp

Post by dobbhill »

Notorious for capacitor failure in the output stage, which presents as DC voltage on the outputs, as you describe. Usually fixable, and worth fixing..
Great amps.....

D
There are no stupid questions, just stupid people.......
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