6N6P tube - focus on

[Zoran]

Sorry about if mu post about the mu vs. gain,
was like a lesson. I didnt meant to patronize at all...
just a few words about, i was not mark clear enough
internal parameters values, in first picture.
.

[Zoran]

With the same circuit parts, like on the SCH for the example,
You can always expect that the stage gain
will gravitate to the mu of tube in point
CCS,
L load,
R load,
Transformer Rload value 1:1 load
with that order close to the mu of the tube

.
But that is not from the first importance,
more is that the sound result is different
and everyone should pick the topology according to personal
taste and accessibility for the needed parts and power supply for.
.
I will try to put together some results of theese 4 different load types
for this 6N6P circuit.

[Zoran]

And Yes, Your measurements are right, the mu and gain are little bit smaller then those given in datas, for those small triodes.

[Zoran]

This is simple CCS with BJTs for 6N6p circuit.
Gain is little higher then with common R load.
And it is approximately the same value then load with L (choke)
No 5th harmonic, and little bit lower noise floor. Amount of current
is changing bt R I set and it is good to be the higher value for the start. for example 100 ohm. This is to be established in real circuit with real elements.
C from b-c is for cut the bandwidth from the upper side and it is optional.
Heat sink atached to MJE350...
.

[vinodt1347]

Hi Zoran/all,

Have you actually constructed this. Iam keen to build a tube pre-amp. Do let me know how this sounded.
Do you have a circuit for the power supply and voltages at the various points in the circuit for testing?

Iam looking at a powersupply at http://www.gyraf.dk/gy_pd/g9/g9_sch.gif

Regards
Vinod

[Zen Mod]

sch from #24 will work , even if I'll check some resistor values (LED models can be somewhat tricky regarding real life - I would use 5mm diffuse green ones , where you can expect 1V93 at 3-5mA through them )

regarding TL783 based series reg ...... I don't like it

use any of HV shunt regs around , Salas made some , for my knowledge

[regal]

Originally Posted by Zoran

This is simple CCS with BJTs for 6N6p circuit.
Gain is little higher then with common R load.
And it is approximately the same value then load with L (choke)
No 5th harmonic, and little bit lower noise floor. Amount of current
is changing bt R I set and it is good to be the higher value for the start. for example 100 ohm. This is to be established in real circuit with real elements.
C from b-c is for cut the bandwidth from the upper side and it is optional.
Heat sink atached to MJE350...
.

I built a similiar 6n6 for a cheap passive I/V+tube PCM63k analog stage a few years ago, it outperformed the D1jfet it replaced sonically and was even close on 2H. Its a good tube but I get about 10 to 20db less thd with the 5842 and have saved the 6n6p for possibly a P-P circuit, they seem more geared toward P-P to knock down some of the 2H softness. I picked the less than optimal operating point simply to avoid a bypass cap.



Alex Cavalia put together a very nice sounding futterman inspired headamp/preamp with the 6n6p, the Bijou, that would be an interesting simulation (its weakness is also the operating point -cathode bias limiting the output.) I think a better cathode biasing mechanism and powersupply it could be a real firecracker.