ecc99 - 6C19n PP, (6S19P)

[tinitus]

Hey, I bought a bunch of 6C19N, to get started

ECC99 seem to match as driver

Should I use SE or PP driver stage

Interstage trafo could be coupled for 1:2 gain with SE to PP configuration
With PP to PP configuration only 1:1 seems possible

I could consider a line trafo, but those are expencive


Would nice with some input on this

[Adolf Corkscrew]

Don't know if this is in any way helpful, but I have a preamplifier using the ECC99. The first half of the tube is used as as common cathode amplifier with a constant current source on the anode, and the second half is a DC-connected cathode follower, again with a CCS. I get something like 56 volts peak to peak with 0.15% distortion and a bandwidth up to 450 kHz (-3dB) from a B+ around 300 volts. I think it could be optimized further, still. The amplification is around the tubes µ ~ 20.

[tinitus]

6C19N tubes

not really sure why I bought them, I just did

please dont suggest OTL; I want these to last a long time

[JLH]

Originally Posted by tinitus

6C19N tubes

not really sure why I bought them, I just did

Maybe you needed to weld something

http://www.mif.pg.gda.pl/homepages/f...13/6/6S19P.pdf

Looks like a Mu of 2 with a Rp of 600 ohms. You could drive just about anything with those things, even with a step up transformer. Mr. Miller doesn't have a chance with that low Rp.

[tinitus]

hey, I found this

input/driver stage looks different from most I have seen, but what is it

[tinitus]

hmmm maybe a mix, with interstage, looks obvious to me, but is it

does it make any sense at all

[tinitus]

ahh, maybe a kind of SRPP
better forget that one

Its my understanding that adding some negative or positive bias voltage is lowering bias current, to make tube run cooler
And I dont think thats needed here

I dont know if it makes any sense to use another driver tube
maybe something with biasing the second driver stage driving the IT ?

Im not sure about CCS on first driver stage B+
I read that it puts hard load on supply

any opinions ?

[revintage]

Originally Posted by tinitus

ahh, maybe a kind of SRPP
better forget that one

Its my understanding that adding some negative or positive bias voltage is lowering bias current, to make tube run cooler
And I dont think thats needed here

I dont know if it makes any sense to use another driver tube
maybe something with biasing the second driver stage driving the IT ?

Im not sure about CCS on first driver stage B+
I read that it puts hard load on supply

any opinions ?

That won´t work! About #1 you must have a CCS-tail and -supply with unbalanced in. Skip #2!

[piano3]

I am building a 6S19P PP at the moment. The driver I am using has a gain of about 35 and my preamp has a very high output-more than 2 volts. ECC99 seems a little marginal in gain as the 6S19P has a mu of only 2 although you could use an input step up xformer as the phase splitter. It would be less expensive than an interstage one I would expect.If I was using a single ended preamp I would probably use a triode connected EF184 differential pair phase splitter with a constant current sink. The gain of this is about 60 and this valve is very linear triode connected.

[tinitus]

Originally Posted by piano3

I am building a 6S19P PP at the moment.

hey piano man, you are welcome to post your results here, or anything related

yeah, I may end up with flea power due to lack of gain

do you know what kind of power to expect from PP 6C19, with optimal gain stage ?
I am told that 6C19 is less good in SE, but much better in PP