Tech advice please on Quad 34 pan pot

Dear technically minded forum members,

I travelled for a couple of weeks and when I returned, my Quad 34 was playing on one channel only. Adjusting the balance lever, I managed to find a sweet spot within a very fine margin to get sound playing through both speakers. Two days later and this effect was gone. If I move the balance lever, there is no crackling sound as one might expect through a dirty pot, and one channel is completely silent. Pressing the mono button gives sound through both channels.

I should note that the weather has been very humid recently and perhaps this has caused the problem.

Technical support for audio gear in my city is very limited, so I'd like to visit a repair shop armed with a bit of information on what might be wrong. Is it likely to be an issue that can be fixed by cleaning the pot? If not, will the preamp need any specialised or Quad specific parts to be repaired?

Thanks!

 

You can try cleaning the balance pot, as that's where the problem is likely to be. Pressing the mono button will do as you found, as the mono switch is after the balance control. If you can check this, you will find that in mono you are getting whichever channel still works, sent to both outputs.

I have a full service manual for the Quad 34, I'm happy to email it to you if you can send me your email address by Personal Message.

If cleaning the pot doesn't work, replacing the balance pot isn't difficult. A spare pot should be available from Quad for very little money, or you may be able to source something similar locally.

Good luck with the repair. It's not difficult if you can find a suitable part, or order it from Quad.

S.

 

Thanks Serge, I just sent you a message

 

There is no balance pot to clean. It is a twin track resistor with a very strange arrangment.



I hope this is not broken as it can be tricky to fix. Quad Service Dept don't touch these as they no longer have the skill to do it.

So searching around the web should throw up some answers for you.

 

This IS the balance pot, at least it was! I don't think it should have been opened up. Now that you have, you can clean the tracks carefully with contact cleaner, and very carefully clean the wiper, then reassemble the whole thing. Hopefully, it should still work, but I would have just unsoldered the pot and replaced the whole thing rather than try and dismantle it.

Good luck with the repair.

S.