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Adcom 5503 not producing Bass

Hey,

Having trouble with Adcom GFA 5503 I purchased off eBay. The amp it not producing any low frequencies. The sound is brittle and very hot sounding. When I switch back to an Adcom GFA 5400 (that I also own), the sound is rich and full. I'm driving a pair of Klipsch RF-3 II speakers. Also, when I hook up the 5503, there is a light hum coming through the speakers. The hum is not present when I hook up the 5400. So, did I get ripped off buying from eBay? I'm thinking about taking the amp to a local repair shop to see if they can help me. Any ideas? What would be causing the amp to not produce any bass/low frequencies?

Thanks so much to anyone taking the time to read this and respond.
schuman

Showing 1 response by georgehifi

georgehifi's avatar
georgehifi
10,312 posts
 
Also, when I hook up the 5503 there is a light hum coming through the speakers.
It’s old enough 25 years, sounds like to me it’s in need of some dried out electrolytic capacitors to be renewed, maybe even the power supply ones also. And there’s lot of them ($$$) All blue things top and bottom, plus there's some on the driver boards. 
https://img.canuckaudiomart.com/uploads/large/946706-adcom-gfa-5503-200x-3-amp.jpg

Cheers George
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