6G6-b 6l6 pin 1 ?

[jamme61]

I recently picked up a fender 6g6-B head. I noticed some one added a 1ohm resistor from pin 8 to ground for easy biasing with DVM. My question is, on the layout it shows pin 1 and 8 tied and grounded. My amp has pin 1 (not tied to pin 8- not grounded? The amp seems to work fine and sounds great - maybe a little more hum- could this be the non-grounded pin 1? Thanks for any help on this

[Jana]

Check the data sheet for a 5881.

[jamme61]

ok I guess pin 1 doesn't do anything thanks

[M Fowler]

If you would like to try EL34's then connect pin 1 to 8 to ground or to ground through the 1R 1% resistor.

[jamme61]

If you would like to try EL34's then connect pin 1 to 8 to ground or to ground through the 1R 1% resistor.

Thanks- would I have to get rid of the 1500 ohm resistor going from pin 1 to pin 5? The resistor is there to stop oscillation right? Do el34's need more bias then 6l6's? sorry for all the questions thanks for the time.

[ToneMerc]

If you would like to try EL34's then connect pin 1 to 8 to ground or to ground through the 1R 1% resistor.

Thanks- would I have to get rid of the 1500 ohm resistor going from pin 1 to pin 5? The resistor is there to stop oscillation right? Do el34's need more bias then 6l6's? sorry for all the questions thanks for the time.

Hmmmm, just thinking here you cant't double duty pin 1 if have bias resistors in pin 1 already. You can stub a 4.7-5.6k grid stopper off of pin 5. To run EL34's you will have to tweak the bias circuit as well, you might have to drop that 27K bias resistor to around 22K. An adjustable bias circuit would be ideal.

[Jana]

You can't leave that resistor there if you use EL34's. Fender often used the unused pin 1 as a tie point for the grid stopper. Pin 1 on an EL34 is the suppressor grid. If you use EL34's, you must tie pin 1 to ground and rewire the control grid wire.

[ToneMerc]

If you would like to try EL34's then connect pin 1 to 8 to ground or to ground through the 1R 1% resistor.

Thanks- would I have to get rid of the 1500 ohm resistor going from pin 1 to pin 5? The resistor is there to stop oscillation right? Do el34's need more bias then 6l6's? sorry for all the questions thanks for the time.

Here's my 6g6b setup for both tube types, grid stopper stubbed to pin 5.

https://tubeamparchive.com/download/file.php?id=25139

TM

[M Fowler]

Mike (TM) nice looking amp.

[Stevem]

You will also need to have enough bias voltage adjustment range to loose some 10 to 12 volts of what you already have to get the 34s happy.

[jamme61]

Thanks guys- just got it back from my tech Dave Sound he does my work and went over the whole amp for me- Great Guy