|
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: Why nor keep it hollow-state posted by Alpha Al on October 11, 2014 at 06:54:58:
Triode Electronics makes a replacement ST70 driver board with two EF86 and one 12AU7 replacing the pair of 7199s. The two triodes in the 12AU7 are split between the channels to provide the concertina splitters. It can take a 12BH7 or ECC99 there too, and there is a version that accepts 6922, 6CG7 etc as well as some other options.
Of course, this only helps in the specific case of the Dynaco ST70. For other 7199 amps where the original sockets must be used, but rewiring is possible, I might suggest a dissimilar dual triode such as the 12DW7 or possibly 6DR7. The high-mu section will still have less gain (by about a factor of 3, or roughly 10 dB) than the pentode in a 7199, but that can be compensated by using less global feedback (which may sound better anyway.)
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- EF86 and 12AU7, and other options - JJ Triode 10:16:17 10/12/14 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
