but its gotta be that one mixer stage thats messed up.
There could be more opportunities for stuff-ups.
everything else is working.
The signal flow isn't clear to me:
- If the Fuzz/Reverb are all parallel then the mixer must be post everything.
yes, exactly. the only thing NOT in parallel, its hard wired to the chassis, and the only part NOT on a plug in card.
I can't imagine the Tremolo being parallel (?) so that would be post the mixer (?)
no, you can pull the entire tremolo card, and the thing still works. its not post mixer, its before it. i told ya this thing is weird. ALL you need working to get sound to pass thru is ONE of the preamp cards.
you can make it work with the reverb other channel, fuzz, tuner or tremolo boards pulled. seriously.
- *If* the main mixer is post everything then the two channels must be mixed together before the Reverb and before the Fuzz. Then the combined signal would then need to be split-off to the Reverb and the Fuzz.
nope. all that shit is BEFORE the mixer board. the last thing in line is the mixer board before the outputs.
remember, the reverb is switchable on/off for each channel, so it obviously is NOT gonna be dependent on being AFTER everything. this is NOT a fender style amp at all. like i said, parallel. they even brag/rave about it in their literature. it was designed so that if any card went down, the rest would still function. the fuzz is universal to the two channels, as is the reverb... tho the reverb has individual controls for off n on, it only has ONE mix control. the fuzz is always on once ya click the switch on the pot, and turn it up.
in order, from right to left from the back, you have channel one, channel two, then the fuzz and reverb boards are next, facing each other mirrored, then the tuner board, then the tremolo board. all of these are individual boards with computer style plugs that they plug into.
all the pots and switches mount to the front face of the chassis by flying leads.
the mixer stage is the very LAST PART of the entire assembly, and it has both channels and the reverb (not sure on the reverb yet) enter it, and off the back, there is one out put for channel two only, and one output with two jacks of the two channels in parallel. the second channel has a switching jack that splits the two outputs, which is the purpose of the mixer stage apparently. it runs on one transistor and a couple passives. there are pictures of it posted already earlier in the thread... there are 4 wires coming off the top, to the output jacks, and all the stuff going in is along the bottom edge
here's the mixer stage i just described. last thing before the output jacks. this is where the entire unit is f'n up.
- The outputs of the Reverb and Fuzz would then be mixed with the output of each channel.
in parallel, not series.
- If there's extra mixing and splitting going on, the fault could occur in the earlier stages.
it can't. is you use the summed outputs, the thing works exactly as its supposed to, all the other cards are working, as can be proven by simply pulling them and putting them back in, as i said. the problem is the output is WAY below unity. the last thing before the outputs is... again... the mixer stage.
the channel two output also comes from there, but appears to be a straight shot thru. when you use the channel two out, it splits the channels to the two sets of outputs, and the channel two only output is LOUD N PROUD the way it SHOULD be... but the reverb doesn't work, which it should. the reverb appears to also hook to this mixer stage.
so... all the channels cards work. the fx cards work. the tuner card works. there are no other circuit board in the unit other than the output board at the very end.
if all the circuits work at the for all intents mono output, and i can again, switch the preamp cards for each other, and both work identically regardless of which is which, obviously the preamp cards are working. the problem, much like in a tube amp, stays with the socket, not the card.
the reverb is working, or there would be no reverb.
the trem is working, or there would be no trem
the tuner part is working as well.
all thats left is that mixer stage, and one side is obviously not working right. that is also the side with the unmarked button transistor that connects to the parallel's output jacks with the low volume, and sounds like playing thru a circuit with a blown transistor. lower volume, more distortion than it should have... but it still passes signal. years ago, i had an old kustom i used as a preamp.. the power amp was cooked, so i took the line out/slave out from it and used it as a preamp for my jcm800 so i had more drive, and reverb and tremolo.
the amp still functioned, and added a good bit of overdrive... but less than unity gain. same exact sympton here bro.
The more I think about it more confused I get with option overload.
hahah.... welcome to MY world.
i assure ya, i spent hours headscratching to figure out what and where the fault is. if it looks like a duck and acts like a duck, its probably not the president. <at least not normally>
this thing is weird, i told ya!!
anyways, process of elimination, the ONLY thing left in the end that can be @#$%ing up is that mixer board at the end. i think its just supposed to be a buffer to stop crosstalk between the channels most likely, which is probably why its just a single transistor.
i couldn't make this stuff up if i tried . seriously!!!!
i would gladly send it to you if you really want to see for yourself. its as @#$%ed up as a soup sandwich. but when its working again, it will be cool.
its literally those 6 cards, the mixer stage, a bunch of switches and pots and an ass-load of wiring.
