Self noise in 414 channel


New member

My 414 mki (original owner!) is generally noisier than it used to be. Particularly, one channel is quite noisy on playback even if I have nothing plugged in. It's similar to white noise and I can eliminate it by turning down the channel's volume. It does get worse when I turn the trim fader up from Line to Mic, so it's not like it's stuck at Mic or something.

What kind of culprits should I look for here? Any caps that I should replace (even if I don't see any bulging)?

The trim and volume faders are a bit sticky-- could the noise come from dust? I have used Deoxit D100 from the surface but would need to fully disassemble the faders to really get the dust out.


Well-known member
If the noise is constant, i.e. does not come and go as you move pots or switches it is likely a transistor or an op amp. You can often pin it down with a can of freezer spray (NOT the stuff plumbers use!). Blast transistor or chip for a second and see if noise reduces. Then put a finger on it to warm it up and positively identify the culprit.

Sometimes a resistor can go noisy but this really only happens in old guitar valve amps that use those crappy Carbon Comp' resistors. Modern Metal Films last forever.