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MarcoVella
Joined: Apr 05, 2011 Posts: 11 Location: Australia
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Posted: Wed Sep 21, 2011 8:38 pm Post subject:
Mini Moog Filter Issues! Subject description: Not Working |
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Hey guys,
Here's the update on my travels with this project. I gave it 15v + and - using two ten cell 1.5v battery rails which seemed to have powered up the unit, because i got heat coming from the IC's, but not overheating, which i thought was promising.
Though, i plugged in my sampler, and ran it through the filter, into a speaker. and unfortunately, i got nothing. no audio came out of the filter. and I'm not sure why.
I'll add some pictures of wiring and the PCB, i think it may have to do with some pcb scratching that occurred when i was trying to get rid of a couple short circuits prior starting the bad boy up.
iif you guys could have a look and tell me what you think could be the problem that would be awesome!
Next question to ask is whether i can fix the pcb scratching at all?
The images are below:
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this is the main pcb connection |
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this here is a burn that occurred during de-soldering of a resistors, i suck i know. it also looks like on the other side of the board i think i may have cut the circuit whilst trying to remove solder, though im not 100 percent sure on this. |
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white leads are my ground, the rest are input/output. |
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main photo all white leads are ground, i have a feeling i have incorrectly wired it. |
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pcb scratches that may have effected the circuit, location: 47k resistors located next to output. this occurred in 3 other locations also mainly involving resistor connections though one is between the ca3046 ic and a resistor. |
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787.76 KB |
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yusynth
Joined: Nov 24, 2005 Posts: 1314 Location: France
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Posted: Sat Sep 24, 2011 10:50 am Post subject:
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Why are the three 150 ohm resistors missing ? _________________ Yves |
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MarcoVella
Joined: Apr 05, 2011 Posts: 11 Location: Australia
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Posted: Sat Sep 24, 2011 8:54 pm Post subject:
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hi yves,
they were removed after testing, just wanted to replace them and will test after they are back in. though besides that do any other connection to the pots or audio jacks look wrong??
cheers |
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yusynth
Joined: Nov 24, 2005 Posts: 1314 Location: France
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Posted: Sat Sep 24, 2011 11:51 pm Post subject:
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The wiring looks correct, though the way you solder the potentiometers is a bit risky, you must make yourself sure that no solder get in contact with the metal shell of the pots or or you metal case. Usually one would not use the fixation holes of the lugs but rather solder the wire on the tip of the lugs. Also if you're not an expert at soldering it preferable not to solder the ICs directly on the board, it is much better to use IC sockets. This way one avoids overheating of the ICs with the soldering iron. I hope that no CA3046 has suffered. The other advantage of using socket is to help debugging because it makes it easier to test and check ICs.
I have a question : can you check and confirm that you used BC547C for the 6 ladder trannies (Q2 to Q7) and a BC557 for Q1 ? _________________ Yves |
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MarcoVella
Joined: Apr 05, 2011 Posts: 11 Location: Australia
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Posted: Sun Sep 25, 2011 2:25 am Post subject:
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when i powered the circuit i felt that the I.C's were receiving power and i measured the voltage and it seemed that the voltage was running through it also. Ill resolder the pots aswell ( i made sure there was no connection to the pot case but the metal enclosure may have interfered. Ill test this all on tuesday, and check the voltages of the ICs.
i can confirm that the transistors are placed correctly i just had a look now i have a slight feeling though that the solder on the pots could have interfered with the metal case, will that cause any severity on the board.
thanks so much for your help yves! |
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