NAD 3220PE Terminal Distortion

[Ratthew]

If you can find the amplifier output inductors elsewhere in the amp, for each channel connect its output directly to the red speaker terminal with a reasonable wire, say #20.

Are these 4 behind the terminals what you mean? Otherwise I'm not sure how to find these inductors.

 

[chrisng]

Did you re-solder the terminal connections to the PCB?

Jan

I think it's a good idea to reflow solder on these two traces.

Otherwise, the simplest thing would be to short the switches out on the bottom of the pcb with two jumpers.

The Same Sky (formerly CUI Devics) SJ-63043H headphone jack pinout looks similar.

If installing jumpers solves the distortion problem, that would prove that the headphone jack switch is the culprit.
Check the dimensions of the SJ-63043H and see if it matches the PCB, maybe it's a direct replacement!

https://www.digikey.com/same-sky-formerly-cui-devices/SJ-63043H

 

[jan.didden]

And cut off those flying lead ends! A disaster waiting to happen.
This is a very amateurish mod.
Also on the attached pic, there are several flying l;ead ends on the row of seven pads near the right that may or may not cause shorts tomorrow or next year or even now. It's been some time since I've seen such bad workmanship ...
Clean that up!

Jan

 

[Ratthew]

If installing jumpers solves the distortion problem, that would prove that the headphone jack switch is the culprit.

Just tried this, managed to bypass the headphone switch but it didn't solve the distortion unfortunately.

Could the re-solder still be a potential solution or is that less likely now?

At a loss for what to try next. The seller said if there were any issues they'd take the amp back, so worst case I'll just have to return it.

 

[chrisng]

My opinion is, send it back! Unless it's really cheap and you're willing to spend the time and effort diagnosing and fixing distortion issues to gain some experience repairing electronics.

 

[jan.didden]

Since really both channels distort (per the posted sound file), a final check could be to measure the supply voltage. Something might be wrong and the supply too low.
That would make most amps distort.

Jan

 

[Ratthew]

Unfortunately I don't have any tools to measure the voltage with.

My opinion is, send it back! Unless it's really cheap and you're willing to spend the time and effort diagnosing and fixing distortion issues to gain some experience repairing electronics.

I think I'm going to have to send it back, at this point I'd rather find another cheap-ish amp that just works.

Really appreciate everyone's help trying to find a solution.

 

[jan.didden]

If you are going to mess with amps you really should get a simple low cost multimeter.

Jan

 

[chrisng]

Yes! Even if you return the amplifier, a simple low-cost multimeter is your best investment for future basic electrical and electronic diagnostic tools, such as measuring whether battery voltage is low, speaker voice coils or fuses are blown, etc.