its been 6 yrs and i finally am getting my build fired up!

[skyripper2]

those resistors were changed to correct values .

[talbany]

So the problem was the wrong value plate resistors on the PI?

Tony

[martin manning]

I would like to see the rest of the power supply node voltages and verify that the PI plate voltage reported is not an error. That’s what I was thinking, since V1 voltages look reasonable. It’s hard to see the color code on the plate resistors, but the bias resistor looks like it’s 820R.

[talbany]

If he had an AT7 in the PI instead of an AX that would be about what you would see
drag everything down and the amp would still sound ok. I don't see how the amp would "sound good" with 110 ohm resistor on the plates

Tony

[skyripper2]

here's what i have for voltages taken.
b+1 436v b+2 434v b+3 406v b+4 300v b+5 292v
and again thanks for helping me with this.

[martin manning]

Those voltages look good. Can you check your PI plate voltages again, pins 1 and 6? I’d expect about 300V there, not the 200V reported earlier.

[skyripper2]

confirmed pi tube pin 1 = 202.9v pin 6=200v

pin 6 voltage on pi tube.JPG

[skyripper2]

the resistors on the pi are reading 110k and 100k.

[martin manning]

Hmm... How about the PI bias resistor and the two tail resistors? And that tube is a 12AX7?

[skyripper2]

i got to bugger for now but will b back and let ya know .

[skyripper2]

bias resistor is a 27k on the bias pot. if i understand what u mean
,the resistors are 110k and 100k on
the trimmer and the other end i have 200k for both resistor values.
and yes it's a JJ's 12ax7 in there.
or maybe this is what's in question 802k-25.5r-361r
I think the 25.5r should be 24k there?and would that throw my pi voltages down 100v? hmmm?

[talbany]

Your voltages look OK but you have a couple resistors backwards should be 820R cathode with a 25K tail.
So your PI was not biased correctly and way out of balance!
You should have somewhere around 40-45V DC on the 820R and around 30-35V on the grids (1Meg)

Tony

[talbany]

edited post:

I think the 25.5r should be 24k there?and would that throw my pi voltages down 100v? hmmm?

Ahhh Yeah
and throw it out of balance!

[skyripper2]

my bad..... it read .802k so that ones in line right?
but the 25.5ohm should be 24k and get swapped out.

[talbany]

my bad..... it read .802k so that ones in line right?
but the 25.5ohm should be 24k and get swapped out.

Yes.Looking at your pics it looks like you have the 820R cathode. The resistor coming off the 2 1megs (grids)and 820R should be 24K not 24R (tail).After you change the tail check it with the voltages I posted earlier and re-post your plate voltages again.

Tony