Right channel (power tube?) ringing [maybe resolved]

[haasaaroni]

Hey there!

Just built the kit and am super pleased with it so far. Passed resistance and voltage checks, enjoying the music tremendously, but there is a slight noise from the right channel (higher pitched ringing), and when tapping on the power tube, I hear the noise happening in the same place as the ringing.

I've also checked for cold solder joints and can't find any muyself, but did see that at B4, I seem to have burnt the white insulator on the wire, right where it attaches to the terminal. I'll try attaching pics of the tube socket from two different angles that show it. Do you think that could be causing some of the noise?

Thanks!
Aaron

[Paul Birkeland]

there is a slight noise from the right channel (higher pitched ringing), and when tapping on the power tube, I hear the noise happening in the same place as the ringing.

Don't tap on the tube.

It is really that simple.

[haasaaroni]

Haha I should have been more clear.

The slight ringing is happening regardless. I thought I would tap on the tube just to see if the sound was originating in the same place. The ringing isn't affected in any way by the tapping.

[Paul Birkeland]

The solder joints at B2 and B5 look like they need more heat and more solder.

[haasaaroni]

Just applied some more heat and solder there, but it didn't seem to change anything. Would it help to send more pictures of the circuit? Maybe there's something else I'm not seeing.

[Paul Birkeland]

Maybe you could send a recording of the ringing.  Ringing when you tap a tube is completely normal.  There are other noises that I wouldn't call ringing that could have other causes as well.

[haasaaroni]

Absolutely! I'll try to get a recording of it sometime today and send it over.

[haasaaroni]

Know what...the power tube might have just needed a slight bit of burn-in  I can't seem to hear the noise at all anymore. I'll keep you posted if I do though. Thanks so much for the quick responses and suggestions!

[Paul Birkeland]

The pins may also be a bit oxidized since these tubes are quite old.  Inserting and pulling out the 6080 a few times may scrape through any pin oxidation.

[haasaaroni]

Thanks for this. For a while the issue seemed resolved, but I had another issue come up just now.

Was insterting a new preamp tube, and I thought I heard one of the LED's do something funny. It's really hard to instert the preamp tube in this...so I took the tubes out to see if the LED's would light up. Now both won't light up. I also resoldered a connection that was too tight and I thought making it hard for me to instert the pins.

All that aside, I took voltages again and got this:

1. 237V
2. 237V
3. 0
4. 237V
5. 237V

6. 0
7. 0
8. 0
9. 0
10. 0

Resistance cheks all passed, but this surprised me! Any idea what it means?

[Paul Birkeland]

If the 12AU7 isn't plugged in, the LEDs wont light up.  The voltages you posted would be consistent with an amp that has no tubes in the sockets.

[haasaaroni]

Amazing. I feel like a genius. Will try and report back.

[haasaaroni]

Being a newby is fun! Such easy fixes! Voltages check out now. And the noise was definitely from the tube itself, since when I replaced the power tube with another, the sound went away. Thanks for answering my questions Paul!!