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BPA300 mono block

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#161
here is a picture during the final test. i will build the chassis this weekend. not sure if i am going to make two separate monoblocks in one case or make two separated cases.
 

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#162
tryonziess said:
has anyone had any luck connectin the s`ingle ended leads directly to pcb for bridge operation. i connected the ground to one + input the the positive to the other + input. my amps sound fantastic with only the cd player driving them. i have a balanced sound card on my computer and will try it next. how is the transformer project going alex
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It is good that you get rid of the noise.

When you connect like this and with single ended input source, you are essentially using only one PCB, which gives 150W max.

I am working on a balanced pre-amp now, after that is done I will try the transformer in my power amp. The transformer is better driven by an active preamp.
 
#164
alex88. anytime i get the drv134 setup even close to the amp project it creates excess noise. i am going to have to work on this or go with the transformer. these units are incredible sensitive to stray signals. i am going to go back through the drv setup and see if something is not right or make a new one. i got the boards from digi01 and they seem to be well made. i still have some excess heat in one bpa150 module. it is not too bad just hotter than the one next to it.
alexcd, i am having problems getting my pictures to be accepted by the forum specs. i will send a few closeups once i get them shrunk to 105k for forum rules.
 
#172
alexw88.. got the caps right where you show them on your amp. i have just enough space under the board for the caps and some air. alex i noticed that the mounting holes at the top of the board go right thru the power traces. i had to install insulating washers at those two standoffs so there was no chance of shorting. just in case some other builders have not noticed.
when i get this project done does anyone want to buy a really nice mcintosh mc2250 amp. i will not need it any longer. alex how about designing a nice 400 watt discrete class ab amp and sell some boards. something good to maybe 1 ohm continuous load. serious now i want to build a good set of discrete mono's i only started this hobby 6 months ago. i do not know a whole bunch but a lot more than when i started. thanks to all of you folks.
 
#173
Variable resistors etc

Hi Alex - is it possible to use 100k VR's instead of 50K? i may hace difficulty sourcing correct surface mount components here - is it possible to substitute standard components? I am planning on using 2 boards in a stereo set up with a single transformer - what is the minimum value transformer that you would recommend?
thanks!
 
#179
sprocket, that is how many i have. ain't it grand. let me check how much i paid alex for them. where are they to be shipped so we can add a tiny bit of postage. i initially planned on building 4 mono blocks or paralleling alex's original design with an extra pair. however, the final result of just the original circuit is great. i am also considering just running parallel instead of bridged. you will like this build. alex did a good job. i am off to a discrete symasym next to try it out. tad
 
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