Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: mikhett on April 04, 2011, 03:08:37 pm

Title: Thanks DOUG! Got a question on a traynor YGM_3
Post by: mikhett on April 04, 2011, 03:08:37 pm

Thanks Doug for the great service over the last few weeks.Im almost finished with the 67 Ampeg reverbrocket restoration.I just bought a Traynor YGM-3 1973 model and would like to add a bias pot to it.The cathodes are grounded so i guess you call this grid bias? Id like some info on how to add a bias pot to this amp. Thanks Mike ( NAVY ET) Former A-ganger!

Title: Re: Thanks DOUG! Got a question on a traynor YGM_3
Post by: rafe on April 04, 2011, 03:53:27 pm

Have you checked the bias information in the library here? Go to; http://www.el34world.com/charts/Biascircuits.htm
see if that helps

Title: Re: Thanks DOUG! Got a question on a traynor YGM_3
Post by: phsyconoodler on April 04, 2011, 03:57:11 pm

It's fixed bias.You need to locate the bias supply on the board,usually a couple of 8uf caps side by side.Then it will have a couple of resistors tied together preceeded by a diode from one leg of the PT secondary.
  Get a schematic(look in Doug's schematic library).
then we can guide you from there.A picture would be great.