Dynaco St 70

[Dave 65]

I set up my Dynaco St 70 that I recieved from Will Vincent. I am shocked at the difference in the sound of my heresy's.

I am using a marantz 2265b as the preamp and as good as the reciever sounded powering the speakers, the st 70 brings out a much fuller,warmer sound and to my surprise added a big amount of bass to the heresy's.

Many people post about how good klipsch speakers sound with tubes and now I can hear for myself it is true:thmbsp:

The amp currently has jj el34's, ge 7199's, and a generic gz34. Maybe I should post over on the tube forum, but would the rectifier tube make a difference in sound quality if it was switched to a vintage tube? Also what brand of output tubes do people like in a st 70? Will told me I can safely use el34,6L6,kt77, or kt66 output tubes.(just need to rebias when changing tubes)

Dave

[Brinkman]

I recently built an ST-70 from the new-production kits and it is what is driving my Fortes.
I did the usual round of modifications and have bought and rolled 3 quartets of output tubes (in order: EH 6CA7s, Winged =C= EL34s, JJ KT-77s) only to prefer the set I started with, the Electro-Harmonix 6CA7s; unveiled, dynamic, and balanced with detailed high-end extention. The JJs seemed dark and bloated, whereas the Winged =C= may require more burn-in (they're in their second rotation). I had the JJs in there for a long time, and when I switched back to the EHs I felt my crossover modifications were better complimented.

However, it really is system-dependent.

-Brinkman

p.s. You may want to experiment with the Weber Coppertop rectifier, as the Weber WZ68 can handle double what a tube GZ34 can, and also considering the fact that the ST-70 is taxing the GZ34 to it's operational limits. Do you know what modifications may have been performed on your ST-70?