Mine must be early, it has the tin chassis although Ive never had a problem with it. It never leaves our studio or travels anywhere. I run it through a Marshall 100/100 power amp with 8 matched SED Winged C's that have been in it since I got it from Psychodave here on the forum years ago.
Yeah, that thing through 2 or 4 412's cranked is a thing to behold
Ive never heard it with 6L6's, I bet it sounds great with those too. I have heard it through a slightly modded Soldano power amp that had been changed to KT88's a buddy has and it sounded great but had a lot of hum, we found one of the power tubes was no longer matched up and was mismatched enough to induce the hum, but I never heard it through the same power section later after he had resolved the issue. He sold it before we could race test that again....
I should have bought it from him, but the Marshall 100/100 with the voicing set to aggressive really delivers the goods..