Trouble with old amp: voltages too low. Bad power transformer?

[slidincharlie (Carlo P)]

Enzo,
the control grids (pin 5) do have some positive VDC on them, more on V4. Such VDC reading is somewhat unstable and changes between readings (maybe due to old solder joints). Thus new coupling caps are due.
One further step onward in the troubleshooting process...
I am going on with checking the other components (not too many after all).
I am pretty sure that new filter caps will cure the low B+ definitely.

Thanks for all the advice. I'll post an update as soon as I install the new filter caps.

[mike60510]

I know this thread is almost ten years old, but thanks!

[mike60510]

I know this thread is almost ten years old, but thanks!

[g1]

I missed this post first time around, but I think a big part of the problem would be using a 6AX4 where a 6X4 is required. (half wave vs full wave rectifier)

[Justin Thomas]

Just try to not jam in those pins in too hard...

I remember when I first tried to jam a 7-pin tube in a 9-pin hole when I wasn't looking...

Justin

[g1]

Oops! Guess it was just a typo then and he was using 6X4.
I guess the filter caps must have solved it.