Just caught the express!

[allclear7]

Just got done with my Express ,and sounds good on the hum/hiss factor.
But have a little low voltage on 3v#6 plate 141vt expected 193vt .any ideas??
Just named her Jenny Rose . (my Wife name) Thanks

[martin manning]

Look over all of the connections on V3b (pins 6, 7, and 8) from the socket to the board, particularly the grid. You can't really measure grid voltage directly on a LTP PI because your meter is upsetting the bias, but that voltage is crazy.

[allclear7]

V3 pin #7 is not 457 just 45vt. I will go from bow to stearn again with checking connections today. It is my first amp build and anit even a shadow to you guys,but learning is what the adventure is about . thanks
ps what is LTP PI ?

[martin manning]

LTP PI = Long-tailed pair phase inverter. Try swapping V3 and V2 just to make sure it isn't the tube that is causing the imbalance.

[allclear7]

I rewired the board today,tried different tubes but still have same numbers.I will just have to get new tubes and see what happens . Thanks again will keep posting progress

[hans-jörg]

Hi,
do you have different anod resistors at PI? Like 82k/100k? This is usualy the reason for diff. readings.
The jumper under the last coupling cap looks dangerous to its leg.
read the resistance of anode Rs and resolder the points around V3b.

You can measure the voltage drop across the both anode Rs. Thats whats V3 anode is lower than B3. Depends on R size. Plus the tubes imbalance . e voila.
I try to use always balanced tubes for LTPPI. Than you can choose to take 100k/100k or 100k/82k (or so).

Best
Hans-Jörg

[allclear7]

The answer to my story is?? http://www.youtube.com/watch?v=boGZoURRQ3Y I think I will be eatin in knoxville today, yea somewhere by Guitar Center( One ballanced 12ax7 on the way)

[hans-jörg]

The answer to my story is?? http://www.youtube.com/watch?v=boGZoURRQ3Y I think I will be eatin in knoxville today, yea somewhere by Guitar Center( One ballanced 12ax7 on the way)

[allclear7]

Went out to my studio and got me a PI tube out of my Tranor YBA-3 Slapped that bitch in and she Knocked me out. This is one sweet amp. Thanks Yall Time to take her to the Tube Dance

[allclear7]

Well I found out a lot i didnt know, about how things work. Mr. Fischer knew there was better amp to be made from what they were serving the public and made it! And thats America at its Best! Thanks to all !!

[allclear7]

After a week of the tube dance, the winners are- PI Westinghouse 1967 12au7a,V2 RCA 7025,V1 12ax7.all out of the 67 Traynor YBA3 Custom Special.
In Francesca I think it is the same set up?
She gose to show on Sunday,with the band.

[redshark]

No, Francesca like any other wreck had european ecc83's (12ax7) in V1, V2 and V3. No other preamp tubes were used.

[cbass]

I thought some of em came with Sylvania's
Not sure bout that

[Randy Magee]

I remember Glenn saying he had some Sylvanias in his Express, but I'm sure they were replacements...

[allclear7]

Ok , What i mean is the type of tube, not the manufacture.This amp has here has Ruby Tubes in its V3,&V2 .ANd by the look of dust on the top of them they look like they were never touched.