KT-88's to EL34s - How do I mod the bias?

[AndyK]

Just got my orange Splawn Marshall SLP. The tubes are original KT-88s that are 4 years old, so I will be needing new ones. I would rather use Mullard EL34 reissues, and change the bias range on the amp.

In my Marshall '78 JMP, I added a resistor onto the existing bias resistor to decrease the range to accomodate EL34s. What do I do in the case of this Splawn Marshall - anybody know?

Thanks.

Andy

[DonaldDemon]

Same thing, it needs a resistor change though I am not sure of the exact value. Do a search on here and you'll find it or call Scott. It can be done pretty easliy it seems.

[AndyK]

Uhhh, a search turns up nothing..?

[AndyK]

I finally got a chance to mod the bias back to EL34 range. I replaced the R30 resistor with a 22k, but the bias adjuster came up short, only reaching 24ma.

So, I have to order 27k resistors (according to Mr. Splawn), since Rat Shack doesn't sell them. Will re-mod this weekend, and finally get a chance to hear what my Splawn Marshall is supposed to sound like!

Stay tuned!

[ALICE]

yeah.