I have the GFA-7805 & 7807 that have kind of a weird anomaly when the 12 volt trigger is connected and the preamp is turned off. All the thermal protection lights are on until the preamp is selected on which then sends the 12 volt trigger signal to the Amplifiers to turn on then the all the thermal protection lights go out after a short 10 seconds, and the relays turn on and sound comes out. These amps are new to me and I have gone through them repairing the timing caps around the 555 timers and replacing some of the outputs in 1 channel in one amp and 1 channel in the other. The only time I noticed this strange anomaly was when i hooked up the 12 volt trigger lines and with the preamp off and amplifiers selected on, but with no 12 volt trigger selected all the thermal protection lights are on and that's a lot of red lights in a dark room. I suspect the standby power supply has an issue. I bought 1 amp from one part of the USA, and the other from another part of the USA. No schematics out there in the wild, but its not to hard to troubleshoot. was just wondering is this the norm for these amplifiers before I get back into them. thanks. Any help appreciated.....
I got my answer from Adcom. This is normal behavior when the 12 volt trigger is hooked up, and the preamplifier in stby mode the thermal protection lights will be on. These is there reply...
12V DC Trigger
When using this feature the front panel Power Switch must be left in the in “on” position. To connect the preamplifier 12VDC output jack to the GFA-7805/7807 amplifier 12VDC input jack.
12V DC Trigger Active
12V DC Trigger
When using this feature the front panel Power Switch must be left in the in “on” position. To connect the preamplifier 12VDC output jack to the GFA-7805/7807 amplifier 12VDC input jack.
12V DC Trigger Active
- Status amplifier power on LED thermal protection must not illuminate all channels.
- Status amplifier power off LED thermal protection will light up on all channels.