Tweedle help....

[bluesy]

Oh, yeah. It works. It’s seems hot, but everyone else seems to think the excessive heat is normal.
I haven’t played through it for very long, though. Just fou d a second issue.....only the first input works .
All the jack wiring checks out. And everything else.... I would like to correct the initial low voltage issue before going any further.

[pompeiisneaks]

It sounds like you've had multiple confirmations the voltages are fine. The point you're looking at can vary from amp to amp, and isn't as important as most of the other voltages.

Since you're getting sound out of the amp, the PI is working just fine. I'd focus next on some close up photo's of the input jacks and where they connect as well as the tube. This will help figure out what's going on there.

~Phil

[bluesy]

DF0B6497-563F-433A-843B-DA15E9323FEA.jpeg

460F58EE-84DE-4CB9-A18D-1AD674F682FF.jpeg

Hope this helps.

[martin manning]

It sounds like you've had multiple confirmations the voltages are fine. The point you're looking at can vary from amp to amp, and isn't as important as most of the other voltages.

The voltage in question (at the grid) will vary with each particular tube, and also with the meter used to measure it. A low input impedance DMM will cause it to deviate from its true value more than a high impedance (10M) meter. The best way to check the grid voltage is to measure both ends of the bias resistor as I suggested above. Really, if the cathode voltage is good, it should be fine, as long as the values and connections for the grid leak and tail resistors are correct.

[fred.violleau]

I can't seem to find the post you were refering to having issues with your channel 1.
Debuging may be hard and painfull, but it is rewarding and a great way to learn.

You get a sound so my advices would be :
- use a wood stick to push each solder point with a cable while the amp is running. When you hear a crack, you may have a weak solder joint. Fix it, reflow.
- if the output and PI is working, work your way back towards the input : check each stage for component values, quality of the solder joints entry and out points.

You will find your mistakes, you need patience and method

Good luck!

Fred.

[bluesy]

Thank you all for the assistance.....Martin..I tried a better meter and the voltage in question is now 18.1! The old meter still reads it at 3.4. The resistors check out.
Now on to the dead inputs....

[ChopSauce]

Roughly, 80% chances are that the dead input is just a matter of wiring, could I read elsewhere.

[bluesy]

Hoping for some input. This amp sounds very nice. After some lengthy playing time, the volume will drop substantially. Fire it up the next day and all is well for an hour....then the volume drop happens. Can someone advise a methodical approach to a paint by number guy to determine the cause? I am most appreciative of this community and the wealth of knowledge you all have and share.
(This amp is a little fire-bottle!)