Adcom GFA-565 Repair Service

The problem:

There could be several problems with the amp but most of the GFA-565 amps have a problem with leaky electrolytic capacitors.
The problem is not a design issue, the amp is very well builded and has excelent characteristics. It seems that during production, the manufacture was supplied by bad quality batch of electrolitic capacitors.
Typically there are few bad electrolytic capacitors on the input board. The electrolyte from bad caps spills over the board and make damages.
First, the electrolyte is conductive liquid which causes servo DC and differential circuits to malfunction. At this point the amplifier can not properly control DC voltage at the speaker output terminals, which has to be about 0 volts. As a result you notice that the cold amplifier make loud turn on/off pop or has distorted sound, but works fine after warming.
On the other hand, the electrolyte is corrosive liquid which cause damages of some components on the board.
As a consequence after few weeks/months, the amplifier gets dangerous voltage at the speaker terminals, up to 70 volts, and can destroy the speaker.

This process is very slow and takes several months before the amp blows the speaker, so you have a chance to notice the problem and save your lovely speaker.

Diagnosing:

Typical noticeable symptoms of bad amp:

• Loud pop when you turn on/off the amp
• Sound distortion, noise when the amp is cold
• Bad fish like smell from the amp
• Overheating

Does your amplifier have one of these symptoms? If so, service it ASAP before you get one of the following symptoms:

• Distortion LED or thermal protection LED is on, no sound
• Fuses are OK, but no power
• The amp blows the fuses or speaker

How to check the amp with a multimeter

Simply check DC voltage across the speaker terminals without input signal applied by using a multimeter.
When you turn on the amp, the DC can jump up to 0.2 volts, then it slowly goes down. In 1 minute it must be stabilized at 0-30 mV (less than 0.03 volts).
If your amp has more than 30mV DC, it must be repaired ASAP.

In any case, even the amp has just noticeable problem or just small output DC, it means that the caps leak process is started and amp must be repaired. The board has to be cleaned, corroded and bad parts replaced

Repair

Altough the source of the problem is simple, the repair is not easy and not every repair shop can handle the repair. The electrolyte has been sitting on the board long time and usually bunch of parts are corroded, some parts can be burned because of amp malfunction, output transistors can be bad.

We have worked with this model for long time, since the first problems occured and have extensive experience in repairing this amplifier. We used different methods of cleaning the preamp board and have found the best solution. Your amp will be 100% fixed. There are no amps which can not be repaired.
We take good care about your amp, we protect your amp from any scratches during the repair.
We use high quality components to prevent future problems. All known as weak or nonstable components also will be replaced.
We provide 1 year warranty. Turn around time is 5 business days.

Note: Unfortunately all GFA-565 GFA-585 amplifiers have that problem, no exception, so you need to service all GFA-565 GFA-585 amps you have in your system.

Our statistic: All of 68 Adcom GFA-565 amplifiers received during 2010-2011 years were successfully repaired. No recalls.