Need Help Trouble shooting

swap those tubes (one channel at a time) also.

Swap the pre>amp ICs and listen for the hum to follow (or not). If it follows, then it's either the preamp or the source, and you then need to restore the pre>amp ICs and swap the source>pre ICs. If the hum follows the source>pre IC swap, then it's the source.

If you determine it's the amp, then as Joeylawn36111 says, you need to swap pairs of tubes L>R one pair at a time, restoring each swap if the hum does not follow, and repeating the process until the hum follows the swap.

It could be a defective cable. Happened to me on several occasions. Try another pair. Good luck, Dave

I did a bit more trouble shooting
and swapping out the interconnect from pre to cdp caused the hum to switch to the other speaker ??
I swapped amp tubes from side to side (monoblocks)
I swapped tubes in my pre amp no difference the hum still exists

Maybe it could be the source
If I hooked up my tuner and the hum disapears is it safe to say it's the source or tubes in the source

If I hooked up my tuner and the hum disapears is it safe to say it's the source or tubes in the source
Musicfile (System | Threads | Answers)

Yes. It could be either. My guess is a tube in the source.

If you swap in the tuner, and the hum still exists, and the hum follows a tuner>pre IC swap, then it's the IC as Dopogue suggested. Be certain the arrows on your ICs are pointing toward the preamp.