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adcom gfa 555


jess28

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hi my wife bought me a adcom gfa 555 for fathers day from ebay.i have been using the gfa 5006 bridged @ 175 wpc wich has been pretty decent crystal clear for movies and tv but for music it's not quite there not very dimensional so i ve wanting to try out the famed gfa 555 .my question is how do i tell if it up to par since i have never heard one my self and i've heard there has been issues with the caps and what not.Is there anything i should look for underneath the hood im guesing it should sound much better than the 5006 in stereo listening.the gfa 5006 that i purchased was from a store who had stock in leftover from when they had last been made so it is pretty much brand (except the fact fact is sat around in a box for x amount of years) and the sound has gotten progressivly better but like i said no where near what i want.So if anyone can give any ideas for when it gets here would really help.

also should i get the 545 and bridge it for the center and sell the 5006 my 806 does a very good if not great job for surround duty it powers my rs 52 wonderfully.

does anyone have any opinions on leaving the adcom running 24/7 i have it an a rack and i rigged some pc fans and it keeps it very cool

thanks guy for all the help

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Do a little research. I beleive it is that line of Adcom that is well doumented to have started fires. I would not EVER use a piece of equipment made by Adcom now that I read about the multiple fires. My advice would be use it in an outdoor system.........near the garden hose, and don't use it with Klipsch speakers, EVER. It seems in every case I read about a fire it was always with Klipsch speakers.

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The Adcom GFA 555 is a nice amp.

If it is the series 2, then the PS caps may be bypassed with smaller caps (aprox 22 or 44uF I believe). Only the later ones had this. I mention it because you can do the same to your Adcom (search the threads over at DIYAudio). It will provide a bass that is a bit more solid or cleaner. It is not a major improvement but it is noticeable. It only cost a few dollars, but do not attempt this if you are unable to identify a power supply cap or if you do not know hoe to discharge a cap with something other than a screwdriver.

As far as bridging, don't do it. Not all amps are very well-designed when it comes to bridging. Your RS speakers should not be that demanding on the amp anyway.

The comments about aging caps are referring to the PS electrolytic caps. If there was a problem they might be bulging and eventually they could leak. That would create a mess. I have owned three of these amps and have not had that problem. If you are concerned, you can get OEM caps from ApexJr at a good deal.

Good Luck

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thanks the rs52 are fine with my onkyo 806 as it stands that is why i was asking about about finding another amp for my center channel (rc 62 and poss rc 64 in the near future} because i wanted my center which sounds decent with 5006 bridged my 806 got grainy at higher volumes the adcom does not. i did want something better maybe the 585 monoblock if i could find one. i have not recieved this amp yet and have not heard it but im not so worried because i know if i dont like i can put back on ebay and recoup my money the seller has a 7 day money back guarantee which is why i was wondered if there was anything under the hood i could look at and it sound like the caps are a good start, so if they look like thaey are buldging then that is not a good sign and if they have leaked then the amp prob wouldn't work at all? i have read alot about the 555 but never heard about them catching on fire though i did hear about the onkyo 806 catching on fire hence the fans which have been doing a bang up job dont know how true these rumors about fire are.

i have heard that the adcom can be bright as well are my speakers but i partially deaf in both ears so i personally have not had this exp.thanks again i love to hear different opinions aa=nd ideas as i am still rather new to all this and every bit'o info helps

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I've never heard of a 555 catching on fire. I've owned several and a good friend of mine has been running four of them since they came out.

A single 555 will sound better than your bridged 5006. Don't bridge the Adcoms unless you have to.

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Guest David H

Yikes! I had a G.A.S. amp do that to me once

Nice classic Dean....Great Ameriacan Sound.... Ampzilla

The PS-Audio PS-200c used to catch fire, it happened once while under review.

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does anyone have any opinions on leaving the adcom running 24/7 i have it an a rack and i rigged some pc fans and it keeps it very cool

thanks guy for all the help

I've had a 555 in and out of my rack a few times. It is a very good amp with lots of headroom. I loaned it to a friend and now he won't give it back. LOL I think he is going to buy it off me. I am currently using a Adcom GFA 7607 (125wpc x's 7) in my HT rig. It has been on since the day I bought it new. I think that was 2004 or 05. Never an issue.

In the winter, I do run a fan on it, as the heater vent is not far from my rack. But in the summer, it is not a problem as the AC keeps everything pretty cool.

Kudo's for having a wife that buys you an amp! [Y][<:o)]

Dennie

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The bad cap problem is only on the GFA-565 & 585, & only during power-up. I did the repair myself on my 585 a few years ago & the amp has been perfect since. The total cost of replacing the 20 year old caps was under $10 & took about 1 hour.

You can usually tell they are going bad when the amp makes a slight hum sound on power-up. As the caps get worse, the hum gets worse until DC is sent to the speakers. Luckily, I did not wait until then.

EDIT: Refer back to this thread: http://forums.klipsch.com/forums/p/119996/1209756.aspx#1209756

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Small electrolytics are only good for about 7~10 years. Complaining about them leaking is like complaining about old batteries that leak and damage your flashlight, it's really your fault.

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This is an original GFA555 (one of two) from around 1985, it gets pounded into multiple K43s on a regular bassis.

I modified them when new with a soft-start, speaker relay, and fans.

Do you ever change the oil in your car? Just asking, I knew someone that had their engine blow up at 25K miles, they has never changed the oil.

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I've had the 555 and the preamp, tuner, and cd player of that series for many years. The preamp has an especially nice phono section. It's currently driving some nice KEF speakers that were built into the ceilings of my home.

It's been on 24/7 for several years now and I've never had a problem. Unfortunately it's on 24/7 because the on/off rocker switch is broken and I've never taken the time to order a replacement and repair it. I've heard of others having problems with the rocker switch so if you open it up check that out too.

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I really liked my Adcom stuff including the 555 amp and preamp. When I finally scored my Klischorns I found it a bit bright and have moved on to to the wonder of tubes, seemed like good quality stuff and I never needed a fire extinguisher.

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i wish i could say she purchased the amp for all the right reasons.it was more about the guilt she had for buying herself a diamond ring b4 i got my fathers day gift.quote (i don't understand why we need more audio equipment!)but when it come to hand bags jewelry or shoes she is all in.

She was impressed enough with the rc 64 to let me drop some seriouse cash though[8-|]

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  • 3 weeks later...

Hey Jess, It sounds like you need to go to Home Depot and get a can of Black spary paint! The only other thing I can think of is a amp repair shop or something like that.

I would stay away from Class D amps for your mains. Subwoofers, class D is fine. Mains......NOT!

Good luck in your search,

Dennie

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