The low level hum is actually tolerable (not ideal). The high pitch whine is making me want to pull out my hair.
Did this happen immediately after finishing the construction, or after some time?
If the former, it could be assembly errors, bad solder joints, and/or damaged parts.
Did you test the output tubes also? Do you have a DVM or other test equipment?
If the former, it could be assembly errors, bad solder joints, and/or damaged parts.
Did you test the output tubes also? Do you have a DVM or other test equipment?
Last edited:
Ok, then did you swap the output tubes between channels, like with the small tubes?
The HF noise could be a bad tube, or oscillation from some other cause.
Try lightly tapping on each tube with an eraser, etc. to see if the noise is affected.
It could be a microphonic tube. Have you tried cleaning the sockets and pins, and RCA sockets?
The hum is likely a different problem, best left until after the HF noise is fixed.
Can you post a schematic?
The HF noise could be a bad tube, or oscillation from some other cause.
Try lightly tapping on each tube with an eraser, etc. to see if the noise is affected.
It could be a microphonic tube. Have you tried cleaning the sockets and pins, and RCA sockets?
The hum is likely a different problem, best left until after the HF noise is fixed.
Can you post a schematic?
Last edited:
Team,
I'm so sorry that I just found the problem. My preamp has two sets of single ended outputs. The right channel on set 1 is bad. It's not the Elekit.
Hunting down these issues is so vexing. Sorry I missed something more obvious. Thank you for your help!
I'm so sorry that I just found the problem. My preamp has two sets of single ended outputs. The right channel on set 1 is bad. It's not the Elekit.
Hunting down these issues is so vexing. Sorry I missed something more obvious. Thank you for your help!
Ok, now the squealing noise is gone, but there's still some low level hum. I'm wondering if the RCA jacks need to be reworked bc there's a poor connection on the ground?
It's possible, especially if this is a recent problem. However, it could also be a failing component,
like a bad electrolytic capacitor. Since the noise is only in one channel, that rules out capacitors
that are shared between channels.
Is the hum still there when you insert shorting plugs into both RCA input sockets?
like a bad electrolytic capacitor. Since the noise is only in one channel, that rules out capacitors
that are shared between channels.
Is the hum still there when you insert shorting plugs into both RCA input sockets?
Hum in Left Channel of TU-8600
Hello,
I just started having an issue with my TU-8600. A low level hum in the left channel has appeared. It has been a wonderful sounding amp since I built the kit a few years ago and I have really enjoyed it. The hum just appeared in the left channel. I moved tubes from Left to Right channel and the hum remains on the left channel. It is there whether there is anything plugged into the RCA jacks or not. I have to suspect a component at this point. If someone has any ideas as to where to start I would be very grateful.
Thanks a bunch.
Hello,
I just started having an issue with my TU-8600. A low level hum in the left channel has appeared. It has been a wonderful sounding amp since I built the kit a few years ago and I have really enjoyed it. The hum just appeared in the left channel. I moved tubes from Left to Right channel and the hum remains on the left channel. It is there whether there is anything plugged into the RCA jacks or not. I have to suspect a component at this point. If someone has any ideas as to where to start I would be very grateful.
Thanks a bunch.