Odd toggle switch located between 6l6 tubes on DC-5

[Jimmy]

I have a DC-5 in my possession that has a toggle switch mounted in between the two 6L6 tubes on the rear. I cannot find this switch anywhere in Mesa land so I'm thinking it could be a mod.

The on/off toggle switch is wired to both 6L6 tube sockets. I'm not sure what it's for. I just know it sounds a lot nicer with more gain when it's in the off position.

Anybody have this?

 

[phyrexia]

maybe it's a pentode/triode switch.

or maybe a fixed/cathode bias switch.

 

[Jimmy]

I do believe it's a pentode/triode switch!

Thanks,

Jim

 

[phyrexia]

Perhaps you could post a picture. I'd like to see how it was done.

 

[Jimmy]

I'll do that!

Jim