Sunn Beta Lead - diagnosis?

[Lester Paulsen]

Hello, new to the forum;

I have two Sunn Beta Lead combos for playing in stereo. One of them has this problem - the volume cuts out with a “pop” noise when I am not playing notes on guitar - after picking notes or strumming, the volume/sound returns, but then cuts out again.
I am guessing that it’s a bad capacitor somewhere - has anyone experienced or repaired a similar problem?

[Lester Paulsen]

I was removing the dials on my Sunn Beta Lead combo before opening the chassis - the dial controlling the “Driver” adjustment on Channel B broke the controller (a variable resistor, I believe), pulling the stem out of the component.

Looking at the schematic, this component is listed either as R144 or R158; I don’t have the list of the components as designated by these numbers. Can anyone help? What is this component?

[Jon Snell]

They are both 1Meg Linear or type A pots.

[drewl]

Common problem with these.

When you pull the PC board out, re-solder potentiometer connections and any other joints that look weak or may be intermittent.

[tedmich]

technically aren't Sunn amps only suitable to play versions of "Louie Louie"?
asking for a friend...

[Helmholtz]

Leslie West with "Mountain" playing a Sunn Coliseum P.A. amp.
IMO one of the best rock sounds ever.

[g1]

technically aren't Sunn amps only suitable to play versions of "Louie Louie"?
asking for a friend...

In fact, this is why when Fender bought Sunn, they put 'LO' at the beginning of all the serial numbers.

[Lester Paulsen]

technically aren't Sunn amps only suitable to play versions of "Louie Louie"?
asking for a friend...

Well, that’s the only song I know on guitar. I want to make sure the neighbors can hear me learning to play. Thus, the Sunn Beta Lead…

[Lester Paulsen]

They are both 1Meg Linear or type A pots.

Thank you.

[Lester Paulsen]

Common problem with these.

When you pull the PC board out, re-solder potentiometer connections and any other joints that look weak or may be intermittent.

Understood. Thanks.