Adcom Repair: Adcom GFA-585 Repair Service
The Repair Service covers ANY repair of the Adcom GFA-585 power amplifier.
GFA-585s are one of the best power amplifiers, but over the years most of them have to be repaired because of the known problem with leaky electrolytic capacitors.
Bad capacitor
Corroded board
Huge corrosion
There are few bad leaking electrolytic capacitors on each input board.
The electrolyte is a 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 without input signal. 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 can cause damage of some parts on the board.
As a consequence, the amplifier gets dangerous voltage at the speaker terminals, up to 70 volts, which can destroy the speakers.
This process is very slow and can take several months before the amp blows the speaker, so you have a chance to notice the problem and save your lovely speakers.
Diagnosing:
Simply check DC voltage across the speaker terminals without input signal 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.
We have extensive experience with this model and know all problems of the unit. We will fix current problem and upgrade all known-as-faulty-parts.
Typical symptoms of bad amp:- Loud pop when you turn on/off the amp
- Sound distortion when amp is cold
- 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
We work with this model long time, since the first problem occured and have extensive experience in repairing this kind of problem. Using different methods of cleaning the preamp board we 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 and protect it from any scratches during the repair.
The service includes a repair of both channels of the amplifier. Even the second channel is ok both preamplifier boards must be repaired.
We use high quality components to prevent future problems. Also all known as weak or nonstable components will be replaced.
Most likely this is a first problem with your amplifier in 15 years. Not bad, the amp is very stable. We belive that after the repair the amp will work another 20 years.
We provide 90 days warranty. Turn around time is 5 business days per amp.
