Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: smackoj on May 11, 2024, 12:00:09 pm

Title: 6AU6 tremolo in Silvertone 1472
Post by: smackoj on May 11, 2024, 12:00:09 pm

Good day amigos; Long time away but still alive and well. Trying to get this 6AU6 tremolo to work better. It's faint and very little change from the Speed and Intensity pots. The volts on pin 6 shows 75vdc but I see 35v on that pin. Anyone have a suggestion? The tube tests new. Thanks in advance friends. JD   

Title: Re: 6AU6 tremolo in Silvertone 1472
Post by: sluckey on May 11, 2024, 12:11:47 pm

Check R31, R32, and C15. What voltage do you measure on socket pin 6 with the tube removed?

Title: Re: 6AU6 tremolo in Silvertone 1472
Post by: smackoj on May 11, 2024, 01:22:29 pm

Hi Steve; pin 6 without the tube is 101 vdc, one of the 2- 330k Rs is 380k the other is 600k. C15 is a new Sprague .62 I had already installed. thanks for your help

Title: Re: 6AU6 tremolo in Silvertone 1472
Post by: sluckey on May 11, 2024, 01:25:09 pm

Try another tube.

Title: Re: 6AU6 tremolo in Silvertone 1472
Post by: smackoj on May 11, 2024, 02:44:19 pm

I don't have another one. I will have to order one. Thanks again

Title: Re: 6AU6 tremolo in Silvertone 1472
Post by: Bieworm on May 12, 2024, 02:50:08 am

Don’t you have another tube amp to try the tube from that one?
It’s better to try a new build with known good tubes. I frequently don’t, but have been soldering the snot out of new builds when it turned out to be a bad new tube after all

Title: Re: 6AU6 tremolo in Silvertone 1472
Post by: smackoj on May 12, 2024, 02:27:13 pm

You would think with all my old parts laying about I would have another 6AU6 but I don't. I did re-do the two 330k Rs at R31 and R32 and put a new cap at C15 as Sluckey recommended. It is now working with no noise. Not real pronounced but good enough for an early 60's amp to use without changing to a better design. Thanks friends.