[jrebman]

I have been looking at Jack Elliano's schematics for his DRD amps and notices that he likes to use the 6an4 as a driver tube, however, TDSL doesn't seem to have a lot of information -- at least none that I can read) on this tube, so if anybody has parameters, and if anybody has used this tube before and can give opinions on it's sonics, etc. I'd appreciate it.

Jack does also say that the driver can be any 15ma, gain
of 50+, 5k plate,  high transconductance type, so if there is something else I should be considering, I'll listen to any suggestions the experienced guys may have to offer.

I do like the idea of a single triode as opposed to the paralleled triodes that Ron Welborne used in his version of these amps -- the 6n1p, which for various reasons is not one of my favorites.

Thanks,

Jim

[mgalusha]

Jim,

I pulled a couple of data sheets. It's listed as a 7 pin hi mu UHF triode.

per the RCA and Sylvania data sheets mu is 70, transconductance is 10,000 umhos. they don't specify the Rp but the curves intersect nicely at 200V and 10mA, so that would be 20K, not very close to 5K. At 150V on the plate there is also an intersection at about 8mA so 18K7. 20K would seem a fairly reasonable value unless operating at a low current.

I did a parametric search in TDSL and there are not a lot of triodes with a mu of greater than 50 and a transconductance of 10 ma/V.

mike

[jrebman]

Mike,

Thanks once again.  From the schematic it looks that the tune is set to run at 220 v, so it's run pretty hot, which is probably a good thing sonically.  I think ol' Uncle Jack knows what he's doing   And these tubes are probably plentiful and cheap.

Did you ever get a chance to look at the 2a3 version?

Thanks,

Jim