Adcom 555 Pro Amplifier

[SoCal Sam]

I just bought an Adcom 555 Pro power amp. It has banana plug and balance XLR inputs. When I powered it up, I couldn't hear the relay click so I popped the top for a look. The outputs were heating up nicely so I decided to try with my test speakers. The good news is it works fine.

There are some serious components inside including a toroid, 4 100v main filters and 8 old style discreet outputs per channel. I could not find the relay so this may be one of those rare modern amps that does not have one. Interestingly, it takes 20 seconds or more for the caps to discharge and stop making music. Very unusual for a modern amp.

I'm aware of the 555 and 555 mk II for home use. I wonder if the 555 Pro is that much different from the home versions.

[Mchaz]

You may have to send it to me for evaluation. :scratch2:

I wasn't even aware Adcom made pro stuff.

[jhal]

:worthless

[SoCal Sam]

You may have to send it to me for evaluation. :scratch2:

Sure, in a few years!!!

I wasn't even aware Adcom made pro stuff.

It looks like the difference is in the inputs and the holes in the faceplate for rack mounting.

[Tedrick]

Couple comments:

A) Adcom amps have no power-on relays that I'm aware of. None of the 3 that I own do. Flip 'em on and they're ready to go. (Come to think of it, none of my Forte amps have relays either)

B) All of the Adcom amps will play for a while after powering off while those big output caps discharge. Yes, it's pretty cool.

C) Adcom sold add-on rack mounts. They show up every now and again on eBay.

D) Nice pick-up!!

E) Some pics would be nice, as I've never seen a Pro Adcom, either.

[nashvillebil]

The GFA-2 has a power-on relay. You don't hear it play on as the caps discharge either.

And it came standard as rack mount.

[SoCal Sam]

I finally got the camera onto my GFA-555 Pro. It has four resetable fuses on the front panel which I guess protects each of the four banks of outputs. The front panel has gain controls which are too small to be convenient.

I'm running the GFA-555 Pro with a Sanyo Plus C-55 preamp.

[idohaz2003]

I bought a GFA-555 just after they came out, shortly after it failed. I returned it to the factory and they rebuilt it for free. Come to find my amp was part of the original development/test amp. In the end my amp had a lot of upgraded parts.
I never saw the pro ever and a number of friends that still have the original.
Adcom is a great company call them they will give you the total story about your amp.

[jhal]

I finally got the camera onto my GFA-555 Pro. It has four resetable fuses on the front panel which I guess protects each of the four banks of outputs. The front panel has gain controls which are too small to be convenient.

I'm running the GFA-555 Pro with a Sanyo Plus C-55 preamp.

Learn something new every day, didn't know such a beast existed.:thmbsp:

[redcoates7]

Same amplifier as the GFA555 with the addition of the balanced inputs and the rack ears. Might have been fitted with the optional fan kit as well (The 565 Pro was anyway)

Nice amplifier...enjoy it!

[jocko_nc]

That's a good lookin' amp ya got there.

[cutra]

I finally got the camera onto my GFA-555 Pro. It has four resetable fuses on the front panel which I guess protects each of the four banks of outputs. The front panel has gain controls which are too small to be convenient.

I'm running the GFA-555 Pro with a Sanyo Plus C-55 preamp.

Holy cow...
i freind at work just gave me a bunch of Sanyo Plus stuff and the same preamp you have...
I have never had a home system and it's all the Sanyo Plus gear.
It sounds great yet what do you think of them.?
I don't have anything to compare it to....

[SoCal Sam]

Holy cow...
i freind at work just gave me a bunch of Sanyo Plus stuff and the same preamp you have...
I have never had a home system and it's all the Sanyo Plus gear.
It sounds great yet what do you think of them.?
I don't have anything to compare it to....

Be sure you thank your friend big time, the Sanyo Plus separates are very nice. I have the whole set including the C-55, T-55, and the P-55 (amp?). They are very nice performers.

[cutra]

Be sure you thank your friend big time, the Sanyo Plus separates are very nice. I have the whole set including the C-55, T-55, and the P-55 (amp?). They are very nice performers.

Of course I did,
he gave me (for free) the following.
All Sanyo Plus 55 series.

2 x amps
1 preout
1 power thing that everything plugs into
1 tuner
1 noise reduction thing (i don't know how to use that thing yet.)

He also gave me a single cd player made by Fisher Professional thing...
Sounds really good.

I have never seen these pieces but they sound surprisingly good.

Great start in my home audio system I think.

[rek100]

Bought my 555 new back in 19 ought 84. I always thought the slow music die out was cool.

However, imagine my surprise when I discovered my newly acquired vintage McIntosh 2100s do the same thing, just not quite as long as the 555. They're about 20 years older than the 555. :thmbsp:

[SoCal Sam]

Thanks for all the GFA-555 replies.

Should I be thinking about buying the matching preamp? What is the model number?

[rek100]

Good question.

I just sold my GFP-565 on e-Bay. I recommend either the GFP-555 (I had one of those, too) or the GFP-565. Adcom also made some tuner-preamp combos. You might want to go to the Adcom website where they have information on their legacy equipment.

http://www.adcom.com/default.aspx