I installed JJ E34L's and E-H EL34EH pairs in my RM100

[skunky_funk]

So I had a pair of matched JJ E34L's and another pair of Electro Harmonix EL34EHs. Placed the E34L's in the inner sockets, and the EL34EHs in the outer sockets. Biased the E34L's at 43mV, and the EL34EH's at 36mV.

HUGE IMPROVEMENT! The E34L's seem to give that extra umph, but still retains that EL34 upper mid. The EL34EH's on the other hand make the amp have the nice EL34 crunch vibe. Comparing it to my stock setup (EL34EH quad) there was a significant improvement in how the notes bloom. It doesn't sound like 6L6s either.

 

[muudrock]

I know from experience that tube combo sounds awesome. You nailed the tonal description too.
I alternate between that setup and swapping 6V6's for the EL34's for a totally different flavor. I love being able to change out tubes!

 

[curtg]

I'm now running an integrated quad of Ruby 6L6's on the outer tubes, and JJ E34L's on the inner 2. Seems to be a "fuller" tone w/ more mid "bite."