I've had several Dual Recs but only used ELs in an old 2 channel I bought back in '97...not sure of the revision. I was into Ministry, Nine Inch Nails, White Zombie, Prong, etc, industrial metal stuff. Loved 6L6s in that amp. Tried ELs in it and it went from sounding like White Zombie with the 6L6s to sounding like Scorpions with the EL34s. Not bad at all but not the 90s sound I was going for at the time so I pulled them. Love SYL so maybe i didn't spend enough time with it.