In Reply to: RE: regulation of screen grid on beam pentodes. posted by beermanpete@socal.rr.com on November 8, 2007 at 22:04:21:
beermanpete, hi. I believe Mike has been thinking along these lines since delving deeper into the world of VR tube regulated screen operation of the beam power tube. Just like RCA (MI-9289) and all the others that did it - is there something to be gained from a sonic perspective by keeping the screen voltage a constant? I think yes. If you look at the gestalte of the tube and its fields having the accelerator grid at a constant potential allows the tube to function in a more ideal way. Audio is not modulating the screen. All you have to do to convince yourself a VR screen is a good idea is listen to an amp that does it. How many amps use BP tubes that don't do it? Plenty. Ultra linear (percentage tap on the primary) makes the screen party to what the plate is doing - kind of a tri-tode. The plate drags the screen along. Maybe more ideal is constant voltage - unaffected by power supply, un-modulated, serene.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- why do it? - elektron 11/8/0722:50:38 11/8/07 (3)
- RE: why do it? - Pat Tobin 06:17:01 11/11/07 (0)
- RE: why do it? - Michael Samra 06:06:00 11/9/07 (1)
- RE: why do it? - beermanpete@socal.rr.com 22:45:58 11/9/07 (0)