300B amp upgrade follow-up:
I have to say that the Jantzen Silver Gold Z-Caps are my new reference for in signal path caps. They have a fantastically natural and clear sound that takes my Treasure 300Bs to the next level. I'm using them as coupling caps in that amp, and couldn't be more pleased. Being that they are 99% silver and 1% gold metalized polypropylene with solid silver leads, they would also be very interesting in speaker crossovers. I'll continue to burn-in the new caps, but I can't image them getting any better.