Hi,
Does anyone have experience of this amp? I've spent ours trying to repair this amp!
I have several Phonic MAX 860 amplifiers and they ALL have the same problem, more or less!
This is the thing:
If I haven't been using the amplifier for a while it goes in to a "no output/clip mode".
I'll try to explain:
When I power on the amplifier everything seems to be Ok. I connect a 8 ohm dummy load to the outputs. All still Ok.
I connect inputs to a signal source and play some music on low volume and everything is still Ok.
But when I increase the volume a bit, (at least) one channel goes in to some kind of "very very weak distorded output mode". The peak led I lighting and the output turns of (almost).
Now I have to turn down the volume and wait a while. Sometimes it "comes back" pretty quick and sometimes I have to wait several minutes or longer.
If I repeat this a few times, and carefully increase the volume until the amplifier goes in to clip (max output), the amplifier works perfectly!
Now I can play forever and drive it to clip constantly without any problems at all! I can turn off and on and play. All Ok. I can leave it powered off a few days and power on and use it and it works perfectly!
Now, if I don't use it for, say a month or so, I'm back where I started, i.e. the amplifier goes in to "protection mode" again and I have so "soften it up" again.
There is no loose contacts or noisy sound anywhere. No scratching sound in the potentiometers at all. When it work, it works 100%
If you know about this or have experience about similar problems, please help!
If you don't, please don't try to guess!
Read this thread instead:
https://music-electronics-forum.com/...-repair/46505-
Service manual can be found here: https://cdn.badcaps-static.com/pdfs/...08af00aa0a.pdf
/Chrille
Does anyone have experience of this amp? I've spent ours trying to repair this amp!
I have several Phonic MAX 860 amplifiers and they ALL have the same problem, more or less!
This is the thing:
If I haven't been using the amplifier for a while it goes in to a "no output/clip mode".
I'll try to explain:
When I power on the amplifier everything seems to be Ok. I connect a 8 ohm dummy load to the outputs. All still Ok.
I connect inputs to a signal source and play some music on low volume and everything is still Ok.
But when I increase the volume a bit, (at least) one channel goes in to some kind of "very very weak distorded output mode". The peak led I lighting and the output turns of (almost).
Now I have to turn down the volume and wait a while. Sometimes it "comes back" pretty quick and sometimes I have to wait several minutes or longer.
If I repeat this a few times, and carefully increase the volume until the amplifier goes in to clip (max output), the amplifier works perfectly!
Now I can play forever and drive it to clip constantly without any problems at all! I can turn off and on and play. All Ok. I can leave it powered off a few days and power on and use it and it works perfectly!
Now, if I don't use it for, say a month or so, I'm back where I started, i.e. the amplifier goes in to "protection mode" again and I have so "soften it up" again.
There is no loose contacts or noisy sound anywhere. No scratching sound in the potentiometers at all. When it work, it works 100%
If you know about this or have experience about similar problems, please help!
If you don't, please don't try to guess!
Read this thread instead:
https://music-electronics-forum.com/...-repair/46505-
Service manual can be found here: https://cdn.badcaps-static.com/pdfs/...08af00aa0a.pdf
/Chrille