GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Audio Discussions
In the Thread: How to get a LOT of SET power.

Post Subject: Drum'n'bass partyPosted by N-set on: 3/26/2011

This thread has triggered some old stupid sentiments. Feel free to remove this post
if irrelevant. I've been thinking how to rationalize my old design in the present context
and make it less idiotic.

First, know the enemy. I don't know the enemy. I assume the bass arrays are very low impedance, 0.5R and require
good controll (damping factor). This should narrow down the tube. Perhaps I'm wrong, but
833/GU-48 does not too look good on paper with their high Rp to achieve good damping,
so I'd stick with 304tl. Apart from Rp at 1.5k level it has one more interesting
degree of freedome to play with: 304th variant with highre Rp if needed.
Biased at 2500V/-250V/120mA and loaded with 7k or so, 304tl should give around
100W, perhaps 120W with a reasonable (?) damping factor, if I'm not mistaken.
The good point is that 304tl must operate at or close to max, otherwoise the tube life is reduced.
5Hz would require 50H primary ind. Doable at 150mA with AMCC800A cores,
1mm gapped, I think 70H too.
To drive I'd go for something non DHT not to complicate:
6E5P DC to, say, EL34 triode connected@400V/60mA and then 1.5:1 stepdown.
Stepdown with 80-100H@60mA primary should be doable too. This should drive 304tl into mild A2 if needed.
PS: I went for the bridge due to the trafo constraints (I had too small lamination), but now I'd do
3kV-0-3kV trafo then 872A FW. For the input and the driver: stacked Romy style supply with mega uF etc.
The most complication is fixed bias...as I see it, due o the DC, each stage would require it's own bias
supply...pain in the ass
THis is something I'd try at this moment, but again--I don't know the enemy, so I'm blind.

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