El34 bias question

Hello,

I just bought a Randall Rm100 second hand recently and it just had the new El34 power tubes put in it. As this Randall is made easy for anyone to bias it themselves I got out the multimeter and read that the tubes were biased to around 22mv.
In the Randall rm100 manual it has a table for biasing different tubes (e.g el34,6l6) and it states for el34 to go between 30 to 38 mv.
I just want to know if you know of why the Mullards would have been put at 22mv instead of 30 to 38mv as it was a guitar technician that did it, are Mullards supposed to run lower ?

Thanks

22ma is very cold biasing for EL34s.

I set them at 34, I was just wondering as it was a guitar shop that did it.

Wouldn't be the first time a shop didn't get something right.
That's why, in '68, I started to learn how to fix guitars and amps.

I don't think there's anything special about biasing Mullards....I never changed anything when I've used them and they've been ok....Can't say I ever read anything regarding keeping them so cool while in operation....I'm a 36ma guy when it comes to EL34s....I like it hot!

Good luck!

I like 33 for EL34's, 31 for 6L6s. I actually have my 5881's at 26 right now... thinkin of cranking them up to 30 to see how it sounds

If I recall correctly, colder bias means more headroom and hotter bias means less? Or do I have it backwards?

I have EL34's and I run them around 45-50. Very hot and it gives the amp a fuzzier sound for the older thrash sound. Very Marshall sounding too, extremely modded tone.