possibility of using SERVO BIAS on Zen v9.

[gionag]

hi guys,
there a way to servo-control the bias of an zenv9 ?

i Noticed that is quite impossibile to fix the right value for the bias of Zenv9 then i'm wondering about the servo bias but my electronics knowledge is very little.

Do you think that there's a way to do that ?
Ciao
Michele

[h_a]

What makes you think the Zen#9 is hard to bias?

Or do you mean to find the optimum bias, the one for lowest distortion?

Have fun, Hannes

[Magura]

Originally posted by h_a

Or do you mean to find the optimum bias, the one for lowest distortion?

Have fun, Hannes

That's really quite simple, as distortion is an opposite function of bias in this case.


Magura

[Magura]

Originally posted by Magura



That's really quite simple, as distortion is an opposite function of bias in this case.


Magura

Sorry, mixed up with Z3


Magura

[gionag]

Originally posted by h_a
What makes you think the Zen#9 is hard to bias?

Or do you mean to find the optimum bias, the one for lowest distortion?

Have fun, Hannes

For thermal purpose...

For finding the optimal bias i've measured the Vgs of the Lu1014 out of the board with test circuit of nelson pass and i've measured a value "out of table" because i read (when it still remain near the room temperature) about 1.2Volt in my DMM.

Then i'm going to try different R3 values while the Vds is 2.5volt... (third method) but the voltage change each minute and the value is going lower and lower for about 1 hour... it's very difficult to choose the right value... i'm looking for a 5 ohm power-pot but i don't find anything suitable.

so i'm interested in a servo that mantain stable the bias trough the warm-up and the operative time, Instead of having a 1000% of THD in first minutes and 0.0000000001% after 1 hour...

any suggestions ?