Congrats Ghanson,
The Yam is a superb amp. As sson as everything is fully broken in, I bet you will begin to hear subtle nuances in recordings that you'd never known existed. There really is no equivelent to well executed SET and single-drivers, it has wholly unique sound of it's own.
"I must beg Darkmoebius's pardon but hum and noise are also ridiculously low and I experienced none of the problems alluded to several postings ago."
I wasn't implying that you were guaranteed to have that problem, just that it was a possibity.
My 6wpc Art Audio PX-25(or Welborne DRD 300B monos), S&B TX-102mkIII transformer volume control, and 97dB Cain & Cain IM-Bens revealed a fairly annoying 60/120Hz AC line noise that I never knew existed. The hum simply couldn't be heard with my mid-efficiency system. As a result, I spent weeks in frustration trying to eliminate the hum from all the wrong places in my system.
Anyway, be prepared for long listening sessions while you rediscover your music collection. That's 2/3rds the fun.