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Adcom GFA-565 Slight Thump

Hello,

I recently acquired a pair of Adcom GFA-565 monoblock amplifiers which I'm using to power my Kef XQ5's. They sound really great, but there is a slight bump from the speakers (midrange) when I turn them on. Is this normal? I've read about the standard repair for a loud thump (I assume from the woofers), but I don't think I have this problem yet. Think it's time for me to perform the repair? Can I test this with a multimeter?

Thanks,
Chris
128x128cjwessing
cdface
12 posts
 
Yep, a normal thump at turn-on (not anywhere near dangerous levels), and also usually a little pop at shutdown. Mine have had the common capacitor repair done, so it's nothing that I worry about. If I remember, I might check the DC offset later just for S&G.
pops
2,273 posts
 
Yep, what they said - mine did the same thing, no problem
hifitime
715 posts
 
I've had them do this it during shutdown on other model Adcom amps I own.I don't remember if this was supposed to be the normal,but mine sure did it.They are in a closet somewhere.I just found it on a Adcom site,and they say the same as Tpreaves said.I thought it may be the caps too but wasn't sure until now.Adcom>>[http://www.adcom.com/faqs.aspx#faq10]
jdoris
972 posts
 
Another former ADCOMer (GFA 555II) who experienced apparently harmless thumpimg. Weird glitch, tho. John
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