audio-talk

Maths is not my strong point, so I turn to PSUD. I also found a nice book http://www.tubebooks.org/Books/Schure_Rectifiers.pdf which helped me out no end. The bit on page 46 concerning fitting a bleeder resistor that draws a constant 10% of the full rated DC current output caused things to drop into...

Potted 4H choke can just about be seen to the rear of the VR tube:

Right then...OK...Er...Here we go again :D I've reverted the power supply to choke input, but this time, before doing anything, I made extensive use of PSUD, feeding in the parameters of the chokes I have, looking at all the waveforms, both current and voltage for any sign of trouble. I ended up wit...

Aye,
keeping the space between both HTs constant seems to work beautifully. Guess it’s one of those happy accidents.

The idea came from the fact that the 6SL7s are drawing around 1mA each and I wanted to use a series VR105 tube to knock around 100V off the HT. I wanted that tube simply because unlike the 7pin VR tubes, it looks great when lit and I only have the one. I had to think of some way to make the tube pas...

A little more experimentation with the power supply today. I've seen series VR tubes used to feed the input stages of commercial amps such as those from Decware and Icon Audio, so I thought I'd give one a try in my own amp: EL34SEULSimplifiedPSU.png 22K shunt resistor makes sure around 15mA is flowi...

Glad they got to you in one piece.

I don’t think they pose any danger Simon. My hairy-arsed soldering is probably to blame for the problems with mine.

I’m glad I got it going again with the JJ and the Sprague caps. It’s a great little amp and the ultimate quality of the sound doesn’t seem to depend on whether or not electrolytic caps or foil in oil caps are used. Yes, of course it is slightly better in the treble, with foil in oil caps but the dif...

Nope,
Still the same as it was.

Not got the text Paul.

Hi Paul,
PM your address and I’ll get them off to you.

I have 4 x NOS, PL36 if you want them Paul. They are Thorn or Mazda (can't be sure until I dig them out) never been used. They have 25V heaters. Might be useful?

Enjoy the music, Steve, that sounds like a good plan for staying off the slippery slope. Yeah that would have been nice; in fact it was very nice indeed...that is until last Thursday afternoon. The telly was on, Melanie was watching "Impossible," I was upstairs, not having turned the amp ...

Enjoy the music, Steve, that sounds like a good plan for staying off the slippery slope. The combination of this amplifier, the Mac Mini and the RTZ DAC (with the higher quality op-amps) is producing the best sound I’ve had in this room…ever! I think, trying to wring anything extra out of the amp m...