2. amps-preamps
  3. 190634-138624

Amp showing its age?

Before getting into details, just the bottom line: can an SS amp, well into its second decade, begin raising its output impedance and/or dropping its peak current capability? Because mine certainly seemed to be doing one or both, so I have just replaced it, and now the speakers are again obedient.

 

hickamore
mswale
53 posts
 

Clean it, get the bias adjusted, and measure the power caps. 

My amp is 50 years old, still 100% stock inside. 

hickamore OP
647 posts
 

@mswale  Too late, already sold and replaced. Oh, well. I was already considering an upgrade. Lucky you on a 50-year amp. What is it, Crown? Early ARC? An amp like that would be a conversation piece if you started a thread on the subject in this forum.

mswale
53 posts
 

@hickamore it sounds like you just really wanted a new amp. I totally get that. 

It's none of them, it's a Hitachi, one of the first FET amps, sounds like tubes, it's huge, and is 60lbs. Tested the power caps several months ago, they were all good. But just measured the bias last month and the right channel is a little off 5%, left Chanel was perfect. Will adjust it next time it get pulled out of the rack for cleaning. 

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