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.
that's a very clean build. almost poetic. Can't wait to see the finished product in full.
Is the case from a supplier or did you make that yourself?
-Jared
Is the case from a supplier or did you make that yourself?
-Jared
The chassis is from Audiosector. Its one of the chassis he sells. It's actually designed for Integrated amp use but this one is not setup that way. It's super heavy with tank like construction.
Nice work !
I like the inside look of that amp. Nice and tidy.
You for sure won't have any problems with the amp getting too hot as the whole case is one massive heatsink .😉
I like the inside look of that amp. Nice and tidy.
You for sure won't have any problems with the amp getting too hot as the whole case is one massive heatsink .😉
😀 Thanks! I'm a little scared to plug it in. Been double checking everything though and looks ok? One question what size fuse do you guys use for these? I got a 6.3amp fuse...I'm not sure if thats too big or to small?
Ok well I plugged it in and no smoke! Thats good lol. The heatsink gets warm but not to hot that I can't touch it. I measure about 31v dc at the amp boards them selves. I guess I should try and play something through it?
I think 6,3 A should be ok because your tranny is rated 6,8 A. (300/(2x22))
For first powering when you are not sure if everything is ok yet, it is best to use some smaller fuse to minimize damage if something goes wrong.
For first powering when you are not sure if everything is ok yet, it is best to use some smaller fuse to minimize damage if something goes wrong.
Ok well... sound is coming out both speakers but one of them its REALLY REALLY low. The other has normal output but lots of noise.
That was my first thought so Pulled them off the chassis but still have the same problem. The amp board thats barely working is getting the same signal as the other and the voltages are the same.
When I don't play anything it sounds like it's picking up a radio station. When nothing is connected to the inputs its silent not even a hum.
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?
when you switch left and right channel RCAs connected to the amp, does the quieter channel switch as well, or is the same one quieter no matter what?
-Jared
-Jared
Same one is quieter. I think it may be a problem with that baord. 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.
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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