6N6P tube - focus on

[Marco audio]

Hi

I use a higher Vdc
You go at 320-360 Vdc
And the use of the trimmer in that position for me is not fine. The contact with current will degrade
For me a good current for each section will be 7/8 mA
With 6H30 with similar circuit I run with 400vdc and the swing is perfect. Of course the resistor are to be well defined
For this I use to put in parallel a high value to fix the equal voltage on both section

Hello,

It's difficult for me to increase the Vdc :
Powerstage run at 340v ,
maximum voltage for my 6j9p by Lamina is 295v at 5ua,
phase spliter and input stage are on the same B+.(I'm saving resistor and capacitor and carefull with phase shifting.PSUD2 give a noise lower than 2mv)
At first i used a dn2540 CCS, it worked fine but a few moment...
Now i'm still waiting for my soundcard, Arta or Rew will be the judge.

I know the trouble with the pot , but i use a strong 2w carbon film pot.
By the way, same trouble is on the bias pots.Here i use two 47k resistor in parallel for each 20k pot.

Question for you : Why do you use a such expensive tube (6H30) for a phase spliter ? Here ,harmonics are disapearing , isn't it ?

Regards

 

[waltube]

Hello,

It's difficult for me to increase the Vdc :
Powerstage run at 340v ,
maximum voltage for my 6j9p by Lamina is 295v at 5ua,
phase spliter and input stage are on the same B+.(I'm saving resistor and capacitor and carefull with phase shifting.PSUD2 give a noise lower than 2mv)
At first i used a dn2540 CCS, it worked fine but a few moment...
Now i'm still waiting for my soundcard, Arta or Rew will be the judge.

I know the trouble with the pot , but i use a strong 2w carbon film pot.
By the way, same trouble is on the bias pots.Here i use two 47k resistor in parallel for each 20k pot.

Question for you : Why do you use a such expensive tube (6H30) for a phase spliter ? Here ,harmonics are disapearing , isn't it ?

Regards

I use the 6H30; in your case can be better due the lower Rp .
When properly configured is a very good solution with a low distortion an reasonable low Zout
The cost , in my opinion, are not important if the results is fine; the quality of splitter is mandatory to get a perfect signal delivered to power tubes.
But the 6N6 works also good.
If you use a C-L-C dedicated only to input stage, derivated from first capacitor, maybe you will get a higher voltage

 

[Marco audio]

I forgot to write about the heater voltage.For 6n6p maximum value is 100v...

 

[waltube]

Yes but elevation is very simple
Two resistor and one cap

 

[mondogenerator]

What do you think about the 6S7B triode ...

This is a strange "subminiature tube" but I believe it is a fantastic one and it cost about nothing on eBay ...

The curves are very linear all over a 350V peak to peak output swing with just - 3,25V bias at 300V 3ma (0,9W) operating point (the maximum Ua) ... So the gain is very high ! It have a 1,45W maximum dissipation and 7ma current. I evaluate the dynamic plate resistance to about 25K at this point, like a 12AY7.

I think I will buy some this winter for tests, they cost about 40$ for a lot of 10 and less than 15$ for two ... It is easy to hookup them on a small "terminal strip" inside the amplifier frame.

Alain.

It's not that linear...
6S6B is far better, but low mu, as you would expect.