Sunn P.A. Eight

[antieatingactivist]

I am looking for a schematic for this. Thanks!

[Enzo]

Someone may be familiar with that, I am not. But what era is that from?

All the tube amp stuff from like 1968 tended to be variations on two schematics.

[antieatingactivist]

Its Big, stereo, Solid state, and has wooden sides. I guess you would call it a powered mixer, one that lays down flat and has lots of sliders. I will try to get a picture of it tomorrow. It has lots of separate circuit boards linked together with wires and plastic harnesses. I am mostly trying to identify all of the wires so I know where to put my signal tracer. Right now its just a big puzzle. Right now I get a hum out of one speaker, nothing out of the other.

[Enzo]

Ooh cool. I don;t know the thing. Boards and ribbons sounds like channel cards? If the speakers are the issue, then the power amps are the suspects. Any DC on either output? You should be able to determine if the power amps run on a single supply like old Acoustic amps or split supplies like most amps. And having determined that, are the4 power amp output stages getting their voltages?

Two power amp channels for stereo. Both on one circuit board? Or two boards, one per chanel? You should be able to find the power supply inputs to them, and the output lines to the speaker jacks. ANd then the signal input connections. You can signal trace there to see if signal is coming to the powr amp from the rest of the mixer. And at that point you can also inject some signal;, even if it is just noise, to see if each power amp functions.

[antieatingactivist]

Thanks for the info. I haven't really done much other than open the thing up yet. I figured I would do my homework first. I'll be sure to post back when I find something. The power amps look really nice. Big transformers along with huge Paper and oil Caps. Getting this thing to work would be really nice. Is there anyone that remakes the sunn style red knobs?

[imaradiostar]

I had one, or one similar to it. Mine had a beer spilled in it and was only partially useful when I got it.

I've saved the transformers and a few other components. It has little pot core inductors in the EQ section that are useful for wah pedals or SVT style EQ circuits.

jamie

[antieatingactivist]

I am looking for a schematic for this. Thanks!

Hey everyone. I just had a non working one of these given to me and was wondering if anyone had a schematic or service manual for it. I get a hum from the right channel, but nothing from the left. I'm not really worried about that yet. It appears that the audio signal doesn't make it through the master mixer board. There are a lot of wires in there and I was hoping to have some direction to find where the signal is stopping. I'm pretty sure I can get this thing running with the right info. Thanks in advance.