5e3 Bright Channel issue

[CRMCRM]

My Weber 5E3 SoWatt is having an issue.

The bright channel has low volume. Even at 10 or 12, it is at comfortable living room volume.
Turning the bright volume nob has almost no effect.
A hard attack on a note sometimes produces static (only on the bright channel).
Normal channel is working just fine and is plenty loud.
It was fine earlier in the week (at least I think it was).
I have been swapping out tubes, if that tidbit is helpful.

What I have tried:
Changed v1 (Jack Darr's book says check the tube first).
I poke parts and connections with chopsticks (no noise to speak of).
Rewired the pots to match the Weber layout.
Swapped the bright volume and the tone pots.
I measured resistors.
I replaced the preamp coupling caps (went from .1 to .022)(I was going to do this anyway)

None of this made any difference.

I have not replaced the caps in the tone stack (I don't have the right sizes handy).

Any chance that I did something to the v1 tube socket while I was changing tubes?

Any thoughts?

[CRMCRM]

I got out my DMM:

pin 1 measured 124
pin 6 measured 132
pins 3 & 8 measure 4.1

I don't know if that tells you anything.

[Platefire]

If it was working fine earlier, I would clean the V1 tube socket with contact cleaner along with tube pins by spraying it on the tube pins and pushing the tube up and down in the socket. If that don't work I would try a different tube in that socket, one of the preamp stages in the tube might be weak.
Also with the amp off, do a continuity check with your DMM on wiring related to the bright channel to make sure no solder joints are shorted. Platefire

[CRMCRM]

Will do. Thanks for the suggestions.

[hackworth1]

Haven't begun to troubleshoot it yet, but my Weber 5e3 Kit has developed the same problem. The regular channel is clean, loud and bright. The bright channel has gotten noisy and lost a lot of gain.

[Platefire]

Well--what did you find?

[hackworth1]

My problem was caused by a short between a resistor leg and the tip of the input jack. I had routed my 1m input jack resistors around the back side of the jacks. So when a 1/4 inch male jack pin is inserted, the jack opened at shorted on the resistor lead.

Seemed easier at the time to solder the resistors on the jacks that way, but I would not recommend it now.

I simply moved the resistor leg away from the jack tip lead and problem fixed.

[Mightyaxeman]

Check your inputs. Make sure your input connections are good and the shorting jacks are shorting when not in use.

[CRMCRM]

This is an old thread, but I thought that I would post the fix.

I had a few days in Chicago last month, so I dropped the amp of at Specimen/Chicago School of Guitar Making. The run an amp building class.

I purchased the SoWatt so I could go after it with a soldering iron. (as an amateur with an iron, I wouldn't have done that with a Li'l Dog, Victoria,...) It was my first soldering project. I toasted the volume pots.

New pots and it is a whole new amp.

[TNO]

Could be bad grounding caused by loose pots. Mine was the same way and I fixed it by adding a ground buss across the back of the pots to the jacks.