Help with Bias on a 68 Super Reverb

[TerryD]

I've done this plenty of times before.  I don't know what is going wrong.   I just got a super reverb that is really nice.  He had TAD 6l6s in there.  They were a tad bright. I put in some sovtek 5881s until I got a used set of RCAs in.  I'm reading the milliamps for each tube.  Black on pin 3 and red on pin 8 of the rectifier tube.  I've done this on other amps I know and for me it's easier with the solid state rectifiers.

The sovteks that looked ok were running at 90 ma each which in my handy dandy little book says that's about twice what they are meant to run.   I have a red violet orange resister on the bias pot.

One of the used RCAs is running real hot and their ma seem to be off the map.  I stopped at 200 or so.

Help please.
Terry

[shooter]

http://el34world.com/charts/Schematics/files/fender/Fender_super_reverb_ab763_schem.pdf

since you didn't post a schematic this is what I'm looking at.
with no power tubes in, can you adjust the voltage?  -52 on linked schematic.

Black on pin 3 and red on pin 8 of the rectifier tube

not sure how you're measuring current for the power tubes here, temp'ing in a 1 ohm from cathode to ground on each 6L6 might be a better way.

[TerryD]

thanks for posting the schematic

[HotBluePlates]

Black on pin 3 and red on pin 8 of the rectifier tube

not sure how you're measuring current for the power tubes here, temp'ing in a 1 ohm from cathode to ground on each 6L6 might be a better way.

It's the "OT Shunt" method.  Works well when you can't solder to pin 8 for some reason, and only measures plate current (not plate + screen current).  Just be sure you don't forget to swap the leads into the right sockets on the meter once you're done; don't leave the leads in the mA jack while measuring V (I found out the hard way this will pop fuses fast).

Measure voltage at the bias pot output itself, then measure voltage at directly at pin 5 of the output tubes.  Any difference?  I'm hoping you don't have leaky coupling caps zapping bias voltage.

[TerryD]

Thanks.  I'm doing better with Gerald Weber's video on youtube  Pin three to the red OT wire to the board.  somehow it seems a more stable place.  Or I just screwed something else up in reading.