In Reply to: Re: regulated screen supply posted by drlowmu on January 6, 2006 at 17:33:41:
Jeff,We discussed pentode operation in a different thread. I think I understand your position and I realize that the ideal screen supply is a separate, low impedance source, so that it is isolated from the B+ sag that can be caused by the large swings in plate current. Regulation is out because it is a source of noise.
Problem is, this requires investment in a second power transformer (plus rectifier and smoothing network) for the screens, plus sufficient space to install it. What about using chokes with sufficiently large smoothing capacitors to provide a reasonably steady voltage for normal listening levels of, say, orchestral music, when the current rises only on transients?
What I have in mind is a PP EL34 stereo amp with an SS bridge rectifier followed by CLCLC network, consisting of:
100uF smoothing cap
5H choke
470uF reservoir, take-off to OPT centre-taps
10H choke
235uF, take-off to screens and earlier stages.Whilst I realize this is not quite the azpproach you recommend, would it be worthwhile to try or just a waste of time, in your opinion?
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Follow Ups
- Re: regulated screen supply - Ray Moth 02:03:54 01/07/06 (11)
- WON'T Work at all Ray....... Waste of time and money - drlowmu 07:19:28 01/07/06 (6)
- Favorite G2 iron parts as of 1-7-06 - drlowmu 14:01:14 01/07/06 (5)
- Re: Favorite G2 iron parts as of 1-7-06 - Ray Moth 08:44:07 01/09/06 (1)
- Re: Favorite G2 iron parts as of 1-7-06 - drlowmu 19:12:06 01/09/06 (0)
- Re: Favorite G2 iron parts as of 1-7-06 - pipo 01:58:38 01/08/06 (2)
- Cap voltage rating pipo - drlowmu 10:00:57 01/08/06 (0)
- Re: FAVORITE G2 Parts, 1-7-06 - drlowmu 09:13:57 01/08/06 (0)
- Re: "Source of noise" - Mahatma Kane Jeeves 06:51:07 01/07/06 (3)
- Re: "Source of noise" - Ray Moth 08:37:19 01/09/06 (2)
- Re: "Source of noise" - Mahatma Kane Jeeves 13:35:11 01/09/06 (1)
- Re: "Source of noise" - drlowmu 14:20:22 01/09/06 (0)