|
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: adapting a design to a different opt posted by vinnie2 on September 25, 2017 at 13:44:12:
vinnie,
you need to "triode strap" the output tubes. connect a 100 ohm resistor from the screen of each 6v6 to their plate. read up on triode strapping pentodes if you want to understand what you are doing.
you then need to remove the global feedback loop. it is attached from the 16 ohm tap on the secondary of the output transformer to the top of the cathode of the 6sl7 input stage. the 1k resistor and bypass capacitor arew what you will remove.
that circuit appears to me to be using a floating paraphase input stage to split phase and drive the output tubes. I don't care for that style of phase splitter.
if the phase splitter still works after those changes you'll have a circuit with a lot of gain and not a lot of deep bass. you'll also probably have a lot of imbalance in the phase splitter resulting in a good deal of 2nd harmonic distortion. I personally have not been able to make the floating paraphase work. I prefer a differential pair with a ccs in the tail.
triode strapping the output stage removes the need for feedback and lowers the gain of the output tubes.
removing the global feedback loop increases the gain of the entire circuit.
the rest of the group feel free to correct me I won't take offense.. I am here to learn.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- RE: adapting a design to a different opt - rage 06:44:12 09/28/17 (1)
- RE: adapting a design to a different opt - vinnie2 08:26:36 09/28/17 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
