In Reply to: 3.1 HUM Help Please!! posted by KDB on December 12, 2012 at 09:54:01:
Hmm, have you checked:
All earth connections in the DAC to the grounds
1. earth bolt on the Digi Board middle rear to the chassis (has to have paint free area for bolt).
2. All earth connections near the AC input to earth on the chassis base (bolt is real tight)
3. Trans are bolted down well, and all connections are good (no dull solder joints)
4. Mains cable is same as one used on DAC 1.1
5. Interconnects are same as used on DAC 1.1
6. RCA or BNC are soldered well
7. Line output wires to the analogue board are good solder joints.
After checking all these, try the DAC 3.1 out of your system through another spare amp to check the hum and imbalance is not the connections to your main system.
After that, it could be a duff Trans (check the voltages against the manual) a faulty cap, or fauly resistor. You can check the resistors with a meter. The caps should also give a reading if you set the ohm on your meter. See if one is different reading to the other.
My guess is you have a faulty connection (solder joint or miss wired).
TAKE CARE if you do anything with the mains connected, as the caps can retain high voltages after switch off.
Failing all the above, I would talk to Brian. He may recognise the behavour?
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Follow Ups
- RE: 3.1 HUM Help Please!! - astrostar59 14:48:42 12/12/12 (2)
- RE: 3.1 HUM Help Please!! - KDB 15:21:51 12/13/12 (1)
- RE: 3.1 HUM Help Please!! - astrostar59 15:32:17 12/13/12 (0)