On Tue, 21 Dec 2004 20:37:23 +0000, Will Reeve wrote:

Guys, here's a stupid idea! I've got most of the bits to make a Morgan
Jones headphone valve amp apart from the mains transformer and choke...so
after a couple of glasses of wine I got thinking. The current consumption
isn't going to be too great (how do you work out the current consumption
of a valve?)...what about 24 PP3 9v batteries in series to give me a clean
216V DC HT. And a wall wart to run the heaters?


You could get it to work with 6.3v valves by using a lot of batteries for
the HT but if you are going to be tethered by a LV lead, why not use it
to get the HT too?

Many of the valves *intended* for battery operation are designed for low
HT and LT, with relatively low current on both. Typical old "combined HT &
LT" batteries gave 90v HT and 1.5v LT. DL91 (1S4) was a typical output
pentode designed for 90v, with a 1.4v 0.1A heater!

--
Mick
(no M$ software on here... :-) )
Web: http://www.nascom.info
Web: http://projectedsound.tk