audio-talk

Isn't having that cathode resistor going to defeat the point? The voltage will vary as the current through that varies. You could reduce it to 83 ohm if you took the grid to 0v, removing the 2M to B+. Or if you used a 9v battery to reverse bias the grid, you could loose the cathode resistor altogeth...

Well Nick, i have to confess that i still can't see why it should be in parallel. For AC use, the B+ and Gnd line can be considered as the same, they are connected via the low reactance of the power supply, so the anode has its load resistor and the following grid leak connected to it, and as B+ an...

Ahh, interesting play. Having a sacrificial pair of speakers to hand.

Just to show how dim I am, whats Internet Messenger? Is it your email client?

Should i take into account the effect of the grid resistor (1meg) on the second 6j5 I wouldn't worry, its far less than 10% of the anode resistor. Can I suggest if you are unsure why its in parallel, that would be worth spending a bit of time, as I think it will help your understanding. Hint: think...

The CCS will work like a much larger cathode resistor, so the variations of voltage will be much less. But the average voltage you measure will stay the same, you would need to use a scope to see how it varies in use.

looks a tad more busy than here

Well they certainly have more members, but you might want to consider the signal to noise ratio as well.

Exactly what problem?

Incase it was being out by an hour, I have changed to GMT, from GMT+1

Itsnot "other" in any real sense but a lot of us used to post on the world design forum (and many still do, nothing wrong with that). Some of the history can found the the threads about the history of why I started this place. There is no competition or anything between the two, but I find...

As far as I can read, many downloaded for nothing, and the average payment was only a £ or so, but the band have still ended up with far more money from the release than would have happened from a conventially industry release. Also I read yesterday, that UK retailers are pressing for non DRM downlo...

Only fly in the ointment IIRC would be the need for a negative HT supply for the sink.

Maybe a couple of pp3's to bias the grid?

Hi-thinking about this,have i really got triode mode ?

I think you have something very very odd. One will be in triode, but the other will have its g2 driven out of phase from its anode.

Just be aware that not all CCS's are equal, and the simple high current ones, may not be that perfect in terms of frequency and phase response.

The LM types are adding a lot of additional circuitry that a c4s doesn't have.

Steve: At 70v I would have thought you were in the range of a pentode CCS?

Sounds very like Allen Wrights diffential amps

http://www.vacuumstate.com/various/dpa3 ... lo-rez.pdf