I added a trimmer for offset and moved the outputs closer to the edge. Had to add one jumper.
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IRF... "GCE" silk, left over from a IGBT design?
Add some rail clamp diodes, protection ckt maybe could have saved the speaker. I hope it was a junk/test speaker.
I smoked my amp too, 2 pairs of MJL3281/1302 as I did not have a proper heatsink. All in the name of science.
Was it one of those quick connects? that I dis-like, because I think they are cheap and unreliable, the contacts loose grip after only a few insertions. I like terminal blocks instead, more expensive but you get what you pay for.A burned pair of Mosfet and a smoked speaker,when one side of power supply, (+/-50v)disconnected by accident
Add some rail clamp diodes, protection ckt maybe could have saved the speaker. I hope it was a junk/test speaker.
I smoked my amp too, 2 pairs of MJL3281/1302 as I did not have a proper heatsink. All in the name of science.
Mosfet Amplifier test.
+/-50v
idle=20mA
I don't think that is good measurement amplifier....
IMD is the highest ι've ever measured!
+/-50v
idle=20mA
I don't think that is good measurement amplifier....
IMD is the highest ι've ever measured!
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Inter Modulation DistortionWhat is IMD?
Is this high indermodulation as a matter of input gnd and power gnd mixing?
I see that Mile's pcb use a separate configuration.
Input and feedback gnd must be separate from power gnd.
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Sorry about that. I copied the layout from post #1126. Here is a layout with the ground separated and the outputs closer to the edge. It also has a trimmer for adjusting the offset. If you want PDF for etching or photo resist let me know.
Blessings, Terry
Blessings, Terry
Attachments
Sorry about that. I copied the layout from post #1126. Here is a layout with the ground separated and the outputs closer to the edge. It also has a trimmer for adjusting the offset. If you want PDF for etching or photo resist let me know.
Blessings, Terry
1k feedback resistor must be connect to input (signal) gnd and power gnd close to 10R/2W resistor.
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1k feedback resistor must be connect to input (signal) gnd and power gnd close to 10R/2W resistor.
How does this look?
Attachments
How does this look?
56nF to power gnd track missing...
Thanks, how's this?
This pcb is ok.
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