Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: pbman1953 on April 01, 2017, 12:59:11 pm

Title: Need to tweak bias resistors
Post by: pbman1953 on April 01, 2017, 12:59:11 pm

For my Traynor YBA-3 Custom-




I need to bring down the cathode side of the measurement. It's high and in the past I was told certain resistors had to be played with get calm it down.


Sorry for forgetting, Thanks.

Title: Re: Need to tweak bias resistors
Post by: sluckey on April 01, 2017, 02:10:04 pm

Can you be more specific? What cathode measurement? How are you making that measurement?

Title: Re: Need to tweak bias resistors
Post by: pbman1953 on April 01, 2017, 02:15:06 pm

Using my Bias Rite, I want to bring down the cathode current. I've been experimenting all morning with changing out R36 . I can't get much change with that so I changed out R39.


R36-15K


R37- 47k


R39- 115K


With this I get a better range

Title: Re: Need to tweak bias resistors
Post by: sluckey on April 01, 2017, 02:20:40 pm

Decrease R39 even more. Leave R36 and R37 alone.

Title: Re: Need to tweak bias resistors
Post by: pbman1953 on April 01, 2017, 02:23:37 pm

Actually I just measured , I'm good with my last settings I wrote you


Thanks