Ok well I'm finishing up a chipamp for a friend because he's swamped all the time and never has time to work on it. My question right now is I have a Plitron 300VA 2x22VAC tranny. The output wires are RED/YEL BLU/GRY. On the little PSU circuit there are 2 inputs that say AC1 and 2 that say AC2 on the other end of AC1 are V- and PG- other side of AC2 are PG+ and V+. My question is which of the output wire from the tranny do I put into the AC1 and AC2 connections? I may have more questions latter so this is just kind of a little build thread.
Ok well I got everything wired up and soldered. Just want to see if you guys think everything looks good? I have not connected an LED yet. I believe you connect it on the rectifier board but I think there is a resistor that goes before it which is not mounted there yet? I'll have to find one. I have not powered it up yet just being catious. Here are the pictures.
have you tried a different source or preamp, or even a different output from the same source (I ask because I use my DVD player as my CD transport and have several different outs, all which have varying levels of noise).
also switching left and right rca channels should tell you if it's the amp boards or the source
-Jared
also switching left and right rca channels should tell you if it's the amp boards or the source
-Jared
Well thats my second concern right now. First on the list is to get both channels working correctly. Which one of them is not its very low. I'm really not sure whats going on? I checked the wiring everything seems to be connected correctly. I switched the RCA's and same thing. I believe its the amp board and I'm suspecting its a component. Maybe the chip it self?
okay, at least we can rule out the source for that.
Perhaps removing the board and touching hot iron to each of the joints to make sure they're solid. This will give you a chance to closely inspect each of the components for any signs of fault, like browned resistors or something. I know I'm pretty much saying everything that you're probably already going to do, but I cant think of much else with my limited knowledge at this point.
its probably just a fluke bad part, based on what I'm reading. I'd hate to think it's the chip, though if it is, at least they're not $50 each.
-Jared
Perhaps removing the board and touching hot iron to each of the joints to make sure they're solid. This will give you a chance to closely inspect each of the components for any signs of fault, like browned resistors or something. I know I'm pretty much saying everything that you're probably already going to do, but I cant think of much else with my limited knowledge at this point.
its probably just a fluke bad part, based on what I'm reading. I'd hate to think it's the chip, though if it is, at least they're not $50 each.
-Jared
Been there done that 
I just pulled the bottom plate off the chassis and flipped it over and then went and resoldered every part on the board. Still didn't help. I'm guessing part of the noise feed back could be the amp board feeding something back into the PSU setup There aren't many parts maybe my friend has extra. I'm sure he doesn't have an extra LM3875 though. How much do those cost? I could probably just order all the parts for one board and that should fix it no matter what lol.
I just pulled the bottom plate off the chassis and flipped it over and then went and resoldered every part on the board. Still didn't help. I'm guessing part of the noise feed back could be the amp board feeding something back into the PSU setup There aren't many parts maybe my friend has extra. I'm sure he doesn't have an extra LM3875 though. How much do those cost? I could probably just order all the parts for one board and that should fix it no matter what lol.
short of discovering something with the power supply not outputting enough power to the board, I think getting all the parts for the channel and starting over might be a good idea.
the chips arent that expensive. I can't quote exact numbers, but I think i've seen them on ebay for something like $5-$6, and you can get them through better sources, if i recall, for probably cheaper.
-Jared
the chips arent that expensive. I can't quote exact numbers, but I think i've seen them on ebay for something like $5-$6, and you can get them through better sources, if i recall, for probably cheaper.
-Jared
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