Tubes Asylum Questions about tubes and gear that glows. FAQ

---

[ Follow Ups ] Thread: [ Display  All  Email ] [ Tubes Asylum ]

---

[ Alert Moderator ]

---

Biasing Fisher amp - can anyone shed light on this?

Posted by PeterI (A) on March 11, 2007 at 21:41:04

I have a Fisher tube amp, number 680-A from a console. I am starting to restore it; it has 4 - 7591 power tubes. I have not touched the bias adjust or the 2 "AC balance" screws on top of the chassis, but after replacing a few components, I will want to check that the bias is correct. I will use the same 7591 tubes.
I did a search on "Fisher biasing" but didn't really find an answer - (but it was an instructional read.)

Can anyone tell me how to adjust the AC balance and bias screw - or should I just leave 'em alone. I have meters, but no o-scope.

Thanks,
Pete

Vintage Voltage Expo - Denver, March 25

This post is made possible by the generous support of people like you and our sponsors:

Kimber Kable

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---