Changing KT66 to EL34

[stevensamps]

Does anyone here know of any real issues when using EL34s in place of KT66s other than having to change the screen resistors and bias ?
I've tried this on a couple of JTM45 clones and they sound great. No problems so far.

[gloeidraad]

Pin 1 and 8 must be grounded when using EL34's

Erik

[neikeel]

Pin 1 and 8 must be grounded when using EL34's

Erik

They are with KT66 in a Marshall

[gloeidraad]

Nobody said marshall

[stevensamps]

Lol, thanks !

[neikeel]

Does anyone here know of any real issues when using EL34s in place of KT66s other than having to change the screen resistors and bias ?
I've tried this on a couple of JTM45 clones and they sound great. No problems so far.

Nobody said marshall

Who else makes JTM45s ? (apart from Metro and all here!) so technically I think he did

Sorry to be so ratty but someone asked a similar question on the Marshallamps forum wanting to try KT66 or EL34 instead of the 5881s and was advised about vital board resistor changes and adding extra ground wires being essential and 'ooh.. be careful - wouldn't try it myself' sort of crap. Of course you can. The only caveats are that if you are using new production EL34s use 1k screen resistors and be aware that you will need to rebias to a point where the bias resistors in series with the pot might need changing

[gloeidraad]

What i mean is that some amplifiers who are not designed for EL34's use pin 1 to connect the screen resistor or gridstopper.
Fender for example.