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(one more) ALEPH P 1.7 clone

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K

koja

Member
Joined 2009
you can buy 1kOhm RelVol3 attenuator board with your choice of a control board for it (say VolCont2 for example) from Mikkel (dantimax.dk). I have them and they work well.

btw: for alephP v1.7: I will be making my own pcb by Xmass time, two sided, no big loops rail-to-ground, and for Wima caps to fit, (could accommodate additional footprints for those interested to join in in sharing the cost). if interested PM me.
 
J

JohnGeneva

Member
Joined 2009
oakpointinvestments.com
Hello all or whomever might still be following this thread. Lots of smoke yesterday. I finished the aleph 1.7 and with my light bulb tester I was getting 62 volts DC of both channels from the power supply, and voltages of 28.9 between resistors 25 and 610 on both boards, just as was shown on Veterans schematic, no smoke, everything good, transistors not too hot, and light bulb tester going quite dim when caps charged etc.


Hooked up to music and mains power and f5 amp, and when I turned music on, I got extremely small sound at medium volume volume levels followed ten seconds later by amazing smoke. Both 2200 uf caps had melted, I saw that I had used 63 volt caps rather than 100 v caps but obviously preamp boards did not seem to work as sound so low.


Do I have a short somewhere that the lightbulb tester did not catch. Or was the smoke just because of the caps I used at 63 volts rather than 100 volts, as perhaps the light bulb tester allowed the caps to charge slowly and safely whereas wall current was too much.

F5 was undamaged, so no problem there.

I ordered 100 v. 2200 uf caps now, and will replace when I get them and test power supply with preamp boards disconnected with lightbulb tester, then with mains power direct. Then I guess reconnect preamp boards to power supply retest with mains tester then direct power and see what happens.

Not connected to amp and music source, no problem at all, and voltages of preamp boards tested correctly. As soon as connected to music source and amp, then a power supply cap meltdown. Anyone have any thoughts as to why this might have happened?
 
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