I have, but don't as much as I used to; unless I really want to light up the neighborhood.
With the 604's this amp is just too much power for my 14'x12' room. Don't get me wrong, at low levels it sounds marvelous, especially in "triode mode", but the combination doesn't sound as sweet as a SE Triode, as Bill will testify.
Mostly I drive them with my G*S*G 6B4G amp. The combination is pretty sweet to my ears, and when I really want to I can still get enough volume to satiate my aging rocker brain.
It's a TAD 60 I bought in 2007, and I've used it in both UL and "triode strapped" mode. Paul Grzybek provided owners with a biasing technique for faux Class A "SE", but I never really liked it, in my opinion, it seems to eat up one of each channel's output tubes - the one that's "hot" biased.
Most recently, I've been using it to drive my restored AR3a's in UL with those wonderful (to me) Tung Sol 6550 re-issues. I like the combination
almost as much as with the 604's, but of course it's really a very different sound.
From time to time, I had been still dropping in my Adcom GFA-555 (I bought it new in 1986, IIRC), but have become very leery of using my aging sweetheart. This amp powered them for
years. In fact for a couple of decades.
If you want concert hall sound levels, this will do it for you!
I used to tune the front door and audio room side window for cranking things up and listening in the front yard. The way my large garage is situated to the side of the house (adjacent to the room), it provided just the right reflection from the open window to actually get stereo separation while seated out front centered between the door and side yard. This arrangement blew away many a mind.
Now I seem to be a little more contemplative about the way I use them. Thankfully.
Best,
Fran
