Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: g-man on March 14, 2024, 10:38:26 am

Title: Pull down resistor question
Post by: g-man on March 14, 2024, 10:38:26 am

Deleted

Title: Re: Pull down resistor question
Post by: sluckey on March 14, 2024, 10:42:11 am

no

Title: Re: Pull down resistor question
Post by: stratomaster on March 19, 2024, 03:54:55 pm

Jack function is unaffected.  However the Traynor version is a slight voltage divider in the high channel, whereas Fender's isn't.  It's only~3% attenuation, so you'd probably never notice it. 

Also, strictly speaking, the Traynor first triode doesn't have a grid stopper and the Fender does. 

Title: Re: Pull down resistor question
Post by: PRR on March 19, 2024, 04:14:29 pm

Quote from: stratomaster on March 19, 2024, 03:54:55 pm

Also, strictly speaking, the Traynor first triode doesn't have a grid stopper and the Fender does. 

Sure it does. The 68k work the same on Traynor as on Fender?
https://el34world.com/Forum/index.php?action=dlattach;topic=31465.0;attach=112483

Title: Re: Pull down resistor question
Post by: stratomaster on March 19, 2024, 11:18:15 pm

I was referring to the order. The grid leak on the Traynor sits downstream of the 68ks, making them the upper leg of a voltage divider in the High input.  Traditionally the grid leak is upstream of the grid stopper precisely to avoid this.  I doubt it makes much of a difference in this instance though.

If the grid leak were smaller I imagine there might be an effect.  Say a 220k instead of the 1M.  Then essentially the grid leak is bypassed by the Miller capacitance when it's directly at the grid rather than upstream of the grid stopper. Haven't done any calcs, so I'm thinking out loud and asking more than asserting.