BalZenPre output impedance question

[claudio]

Hello,

I would like to know about the output impedance of the Balanced Zen Pre: not using the P3-P4 pot, the output impedance will be given by the sum of R1 + R3 ?
I would like to use this pre with the Ciuffoli's Power Follower , but this ampli accepts a maximum of 300 ohm impedance from the pre.
Thanks

Claudio

 

[claudio]

BOSOZ question

Hello again,

is anybody going to answer this post?

Thanks 😀

 

[HarryHaller]

Brazil

The output impedance of the balanced zen preamp is R2 plus R10 or 971 ohms. This should be fine. I believe the Ciuffoli's Power Follower frequency response graph show a -3dB point of about 150kHz with a 1k source impedance driving it which sounds reasonable for an IRF 150 as a follower. Email me and I will tell you where to send the check for design consulting.

http://www.geocities.com/ResearchTriangle/8231/my/Follower_99c.gif

http://www.passdiy.com/pdf/balzenpre.pdf

H.H.

 

[claudio]

Harry,

thanks for the answer. Actually Mr. Ciuffoli says different things about the pre-output impedance: in the "COMPLETE CIRCUIT " page he says "..OUTPUT RESISTANCE NO MORE 300 OHM", while in the "COMPLETE ARTICLE WORD" page he says: "..and should be preceded by voltage gain stage, with an output swing not lower than 10Vrms and Rout < 1000Ohm."

Little confusing, isn't it?

I tried to email you, but the Administrator said I can't! 😕

I wrote the Adm to see if there is a way out.

Claudio

 

[HarryHaller]

Output impedance

Less than 1K is fine. I built a similar amp it sounded fine. It is a very good circuit. Go build one, I think you will love it.

H.H.