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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
 
Adcom emailed me back. They say the heat is likely a bias adjustment issue & the differing levels of hiss could be of concern.

The person I got it from has 2 more, so I may try another, but I'm also not real thrilled with the sound. I didn't think anything could make my NHT's sound bright; I'm used to them being a bit on the dark side! Being on a budget, one of his other amps may still be a short term solution, though.

Thanks for all the replies both on & off list, much appreciated!
abstainer91
1 posts
 
I've owned two ADCOM GFA-555s. On both the heat sinks got quite hot, "almost too hot to touch", with no ill effects. The longer they ran, the better they seemed to sound.
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
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