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Adcom 555 Mk 2 Questions

I'm a newbie here. I'm hoping someone is familiar with the Adcom amps & can provide some insight.

Long story short: My NAD 2600 blew up from static electricity. A friend who is not an audiophile has offered me an Adcom 555 Mk 2 really cheap for $150.

The rest of my system is: Teac Esoteric P-10 transport to PS Audio sl3 D/A by Illumanati cable. McCormick Line Drive Deluxe passive pre. NHT 2.5I speakers bi-wired. All analog wiring is Tara. Also have analog components & a Pioneer universal SACD player. Listening comments below are with the digital front end.

I just plugged the Adcom in (I'm told it hadn't been used much lately) & have 3 concerns. With all 3 concerns, my question is, "Is this normal behavior for an Adcom amp?

1. The heatsinks are quite hot from playing 4 songs at normal volume

2. There is some light hiss in both channels, even with the input muted. One channel has more hiss then the other

3. The amp is quite a bit brighter then the NAD. It may need to warm up for awhile (though again, the heat sinks are almost too hot to touch)

Thank you for your answers!
moomoo
moomoo OP
81 posts
 
Abstainer, did you leave them on 24/7 (which I'd like to do)? I assume if so, you experienced no fire hazards...

The potentiasl for a fire hazard is my biggest concern. Sound quality is sadly somewhat secondary as I'm really broke right now & I suspect I'd eventually sell the Adcom if I buy it, but I'm so used to leaving all my gear on 24/7 I'm certain I'll occasionally forget to turn the Adcom off.

I still am looking into this between the pain of getting my NAD fixed & the cheap $150 price on the Adcom.

The one good thing about the Adcom is the static electricity that caused this in the first place appears to be gone.
moomoo OP
81 posts
 
Ironically after writing the above, I just noticed that I did leave it all night & all day today. No fire, but it's REALLY hot.
kencrouch
10 posts
 
I am the original owner of an original model GFA-555. This amp has been on 24/7 its entire life - intially with Magnepan MG2, then small JmLab, and now Paradigm Signature 8 - the heat sinks on my amp never get hot - rarely if ever even warm - checked them just now - listening at low levels they are dead cold. This has been a great amp for me - maybe I just got a good one but I have always been very satisfied with the sound and performance of this amp. YMMV -

Ken
kats
26 posts
 
Moo, I've had a mkII for about 15 years without any problems whatsoever. When it was my only system I ran it 24/7. At idle it runs just slightly above room temp, but the longer/louder you push it the hotter it gets. Never really gets too hot to touch though. I recommend leaving it on 24/7 if possible for best sound. I use it sparingly lately and turn it off/on as needed - big difference in sound quality IMO. Not the smoothest amp around I'll admit but sounds very good with speakers that are voiced a bit on the warm side like my VA Bach Grands. Pushes them to the limit with great control. Probably not a great match for NHT which, from what I've ever heard, are a bit on the bright side.
Bottom line: still a great amp for the money though if the heat does bother you get it checked out.
moomoo OP
81 posts
 
FYI, it turned out the amp was bad. Hissing kept getting louder, then it died.

The person who I got it from had another. So far this one is running much cooler, with no audible hiss. I'm still not thrilled with the sound (though it may need to break in, I don't believe it's been used in several years). If it continues to be stable I think I'll buy it ($150) & continue to look for a repair option on my cheaper but better sounding NAD 2600. If I ever get the NAD repaired, I should be able to sell the Adcom at a small profit.
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