|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
|
|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
In Reply to: RE: EICO HF-89 restoration posted by Jim Doyle on August 29, 2010 at 18:41:06:
Jim
The gain stage 12ax7 is already direct couple to the 6sn7. As a matter of fact,the only coupling caps used are the .1s to the outputs and the .22 or .25 decoupling caps.
I agree that the 7199 was a total POS. It was great in integrated amps driving 7189s or 7591s but not when you want to drive higher power pentodes. My one HF87 I left cathode bias but,I didn't keep the DC filaments that were derived from the cathode voltage of the el34s. Was that a waste or what? I just paralleled 4,5 and use pin 9,ac filaments. The hf87 does that have the bias tap on the PT.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- RE: EICO HF-89 restoration - Michael Samra 08/30/1009:22:20 08/30/10 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
