Preamp/ buffer for F2J amp

[kinku]

Hi,
Now I am finished with my F2J it seems like I need a good preamp to go with it.
I don't need real amplification but possibly a buffer and attenuator. A B1 board is in the process of making.
Since this amps input impedence is only 10K( compared to F2 , 50K)
Is B1 the right design I should look for ?

 

[Zen Mod]

do not worry


latest iteration of B1 is having Rout under 50 ohms or so

 

[Hikari1]

Zen is talking about this:

B1 Rev. 2

If you only want a buffer it's very nice.

I believe the regular B1 has a z out of around 300R. Should be fine as well.

 

[Zen Mod]

with 1K (foolproof part) series resistor , hardly 300R

dunno did Papa decreased it later ......

 

[Hikari1]

Zen is right. I would use 200R, Problem solved.

I believe the DCB1 (Salas' version) used 200R series resistor. Should be fine especially if interconnects are short and not fancy I would think.

But B1 Rev2 is probably the way to go, assuming one has the jfets.

 

[gadut]

how about this one, Jfet front end with extra muscle output

The α20 line stage amplifier