Very faint hum
- Thread starter Jimb0
- Start date
The ringing sound is completely normal and normal with 6C45P operation.
Does the faint hum change in magnitude when you switch impedances? If you listen to a 60Hz and a 120Hz tone, does it sound like either?
Does the faint hum change in magnitude when you switch impedances? If you listen to a 60Hz and a 120Hz tone, does it sound like either?
If the impedance switch doesn't change anything, what happens if you unplug all your sources?
What headphones are you using? Is this the new Mainline with the universal power transformer? If so what is your wall voltage? How tight is the hardware on the power transformer?
Can you double check your voltages to be sure they are all in line?
Have you tried the Mainline in a different room to be sure the source of hum isn't perhaps something close by with a power transformer that just happens to be perfectly aimed?
Have you tried the Mainline in a different room to be sure the source of hum isn't perhaps something close by with a power transformer that just happens to be perfectly aimed?
I rechecked the voltages today and they checked out okay. Also tried moving to a different location but the hum is still present
Also I forgot to mention that I had to extend one of the wires from the CAT-5 going to the XLR output. I just used some extra wire and soldered both ends together. Is it possible that this is causing the issue?
Also I forgot to mention that I had to extend one of the wires from the CAT-5 going to the XLR output. I just used some extra wire and soldered both ends together. Is it possible that this is causing the issue?
You could try this modification:
https://forum.bottlehead.com/index.php?topic=11676.0
Extending that wire as you did is unlikely to cause hum issues, but I would cover up the exposed solder joint with some nail polish or RTV.
https://forum.bottlehead.com/index.php?topic=11676.0
Extending that wire as you did is unlikely to cause hum issues, but I would cover up the exposed solder joint with some nail polish or RTV.
Hmm, maybe post some photos of the build. Perhaps there's something we can spot.
The black/red twisted pair of wires needs to be way, way far away from the input wiring. In the stock build, it wraps around the back of the OT-3 (it won't do much harm there), but in your build it has been brought back and run in parallel with the input wiring.
