"Andy Evans" wrote in
message


if you want really good regulation,
you still can't beat the venerable LM723.

Note that I really need an absolute minimum of 2A current
handling, so LM723 is out and LM317 is too marginal -
tubes need between 1.25 and
1.75A.

LM323 is rated for 3 amps.

LM 338 is rated for 5 amps.

No virtue in batteries, and a pig to implement. I have
tried, but a good current source sounds just as good as
long as you can get the hum right down.

Agreed.