Home Tubes Asylum

Questions about tubes and gear that glows. FAQ

RE: Phase inverter tube choice question

V1 is a differential gain block phase splitter, AKA long tailed pair (LTP). The theoretical max. gain for such a setup is 1/2 the amplification factor (μ). In practice, roughly 1/4 μ is obtained. Kudos to the designer for using a constant current sink (CCS) load in the LTP's "tail".

That 1/2 V2 is a ubiquitous common cathode voltage amplifier. The bottom line is that all the small signal tubes in this setup are amplifying and, therefore, the non-linear 12AU7 should be eschewed.

As long as sufficient heater current is available from the power transformer, only 12BH7s should go into that unit.


Eli D.


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


Follow Ups Full Thread
Follow Ups

FAQ

Post a Message!

Forgot Password?
Moniker (Username):
Password (Optional):
  Remember my Moniker & Password  (What's this?)    Eat Me
E-Mail (Optional):
Subject:
Message:   (Posts are subject to Content Rules)
Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:  Automagically notify you when someone responds.