Help with Adcom Equipment

Roshisan1 · August 2015

Hello, I have a few questions about a GTP-760/GFA-7000 I acquired for about $190.00 a few years ago.

GFA-7000

1. The plastic cup that holds the power button has come unglued from the aluminum faceplate. It looks like it may have been hot glued previously but I can't imagine that Adcom did that from the factory. What are your recommendations to reglue it?

2. On the left channel pcb, the large blue caps have a bit of peanut butter colored substance on top of them. Is this leaky electrolyte or just some residual glue?

GTP-760

3. Any idea where I can get 4 replacement rubber feet (part number 13005805) and the screws to install them?

Both

4. What is the cheapest way to ensure the amp and preamp are up and running properly so they won't damage my speakers as some Adcom amps have been known to do.

Thank you for your help.

tonyb · August 2015

I'm no Adcom guru, but I'd imagine re-gluing the power switch would work. If you want to replace it, look on Ebay.

Rubber feet can be found in numerous places, Parts Express should be high on the list.

Hard to tell about the caps without a pic.

The best way to make sure both pieces are up to snuff is to have them checked out by a tech. Not the cheapest though. If you can test them on some junk speakers to make sure they are operational before putting them on speakers you like, that might give you some guidance. I've never really heard of Adcom amps ruining speakers, it's always been the operator who pushes the limits.

Roshisan1 · August 2015

Thanks, tonyb. There are some threads around about older Adcom amps sending a DC offset into speakers and frying them due to the amps not having any built-in speaker protection. I think this was a problem with early amps only but since I am on a limited budget, I cant take a chance. I have an LSI 9/7/C setup as well as a pair of Klipsch Forte II and cant really afford to replace any of them. I will get a couple of pics up as soon as I can.

Roshisan1 · August 2015

Here are pics

tonyb · August 2015

That cap in the second pic isn't looking too sharp.

If your on a budget and can't take the risk.....why may I ask are you looking to hook this up then ? Always going to be some risk, especially with no speaker protection.

Wouldn't it make more sense to get a more current amp that has built in protection ? Just askin' is all, ounce of prevention is worth a pound of cure and all that.

Roshisan1 · August 2015

I hear you loud and clear. I used to love the Adcom sound and need to see if I still do. Since I have so little money in this amp ($140.00). I feel like I can get it up and running for much cheaper than I can buy a different amp, unless you have other ideas..

F1nut · August 2015

Neither of those caps look healthy. Replace them as well as the two for the right channel.

These would be an excellent replacement, http://www.analogmetric.com/goods.php?id=2129

F1nut · August 2015

These would also be a good choice, http://www.analogmetric.com/goods.php?id=1029

Be sure to check the size of yours before ordering new ones.

Roshisan1 · August 2015

Thank you F1nut. Would these provide an improvement in sound quality as well? I was curious because they are 7 or 8 bucks more per cap and if I have to replace two, I might as well replace all 10...Additionally, does anyone know of good outboard speaker protection or should I just fix the caps, sell the GFA7000 and GTP-760 as a combo and get something else?

F1nut · September 2015

Yes indeed, they will improve the sound. Between the two choices I mentioned I'd get the Elna's. Mundorf's are the best and my favorite, but they don't offer any in the values you need.

Those caps will need to burn in, the Elna's take about 200 hours. Mundorf's on the other hand require 300 hours.

That said, if you plan on selling the amp I sure as heck wouldn't put TOTL caps in it.

You could add a fuse after the inputs on your speakers, but I wouldn't.

tonyb · September 2015

Roshisan1 wrote: »

or should I just fix the caps, sell the GFA7000 and GTP-760 as a combo and get something else?

Depends, but I'd more than likely be looking at something else. I'd replace the 2 bad caps only and give it a listen. If you like what you hear and plan on keeping it, then I might think about replacing all the caps.

Most vintage gear is going to need some work done for the obvious reasons. If your handy enough and don't mind putting in the time/effort/money, it can be a worthy proposition.

Roshisan1 · September 2015

Thank you for the advice. I really appreciate it.

Help with Adcom Equipment

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