Tube Buffer Preamp Design

[mashaffer]

As I understand it the 12AU7 is one of the tubes that is relatively tolerant of low plate voltage. Since you only need gain of about 2 why not do an anode follower with the Rf adjusted for gain of 2. This will keep the HD in check.

Something like this.

 

[tonimxp]

Hi Mashaffer, please could you simulate also diagram of my post 56?
I would like see differents.
What do you think about 12au7 vs ecc88 to use in this case?
Thanks

 

[egellings]

Constant currents sinks and sources have a high Zout. That's why they're used.

 

[mashaffer]

Ah, that makes sense. I hadn't thought about the drive being a current source. In that case the anode follower I posted would not make sense. Better to use FB to the cathode in that case I think but I am not well versed in I-V converters so I best bow out, watch and learn. 🙂