6922 Technical info (help)

[Blixa]

Hi everybody..
I'd like to know the output impedance of my tube preamp, using a web calculator, but i need to know Ri and gain of 6922 and for me (newbee) it's still too complicated to measure these values.
Is there anyone that have indicative values about this?
Thanks in advance guys!

Marco

 

[jazbo8]

What are the plate and grid voltages?

 

[rayma]

What are the plate and grid voltages?

And also the schematic diagram. The tube's operation depends to a large degree
on the associated resistors, capacitors, and power supply voltage.

 

[Blixa]

Thanks for reply 🙂

@Jazbo: what do you mean for "grid voltage"?
The anode is 180v

@Rayma: i haven't the real schematic, the only one that i have received from seller is wrong.
I should be check the pcb and try to draw real scheme.

 

[rayma]

i haven't the real schematic, the only one that i have received from seller is wrong.
I should be check the pcb and try to draw real scheme.

Can you post clear, close photos of the front and back of the pcb?

 

[jazbo8]

@Jazbo: what do you mean for "grid voltage"?

The bias voltage, if it is self-biased, then it is the cathode voltage.

 

[DF96]

Have you tried finding and reading the valve datasheet?

 

[Blixa]

Hi
Sorry for delay!
Solved with your suggestion and help of a friend of mine (thanks Giancarlo!):
i found tube gain (33.13mu), Ri 2.65/2.67k and 2 resistors value, the impedance is approx 1.3k not bypassed and approx 715ohm if bypassed..

Thanks!!