20th Shiva tubes

[just42dave]

I put black Sable 6550 in my shiva and helped it out alot.. Do I need to do a resistor change to try el34 and 6l6 as it has a wide range sweep on the bias,,
Also bought the Sur mini mix II itll be here soon I really dig this amp..

 

[just42dave]

?

 

[glip22]

Does your amp have another resistor piggybacked on the existing bias resistor? If so remove the top resistor and you may be able to bias up the 34's. If not desolder the resistor from the board topside. It will come out very easy. I'm not sure what value you will need for 34's.

 

[just42dave]

the long grey one??
The sweep will go down to 34

 

[glip22]

the long grey one??
The sweep will go down to 34

No they are blue metal film. You arer able to bias the EL34's to 34ma. Makes no sense if you are biasing 6550's in the amp. You should only be able to bias the 34's to maybe 10-15ma if that with no resistor change.

 

[RockStarNick]

There should be a piggybacked resistor. You will need to clip it to get the bias in EL34 range. Trust me.

It's reversible, but reversing it is harder than snipping it.

 

[glip22]

Just desolder it.

 

[just42dave]

ok