output impedance of source follower and load in mH?

[AudioGeek]

If i wanted to load a pair of push pull source followers with a transformer similar to the susan parker design... how do i determine what primary inductance is needed and with a particular output impedance of the source followers what should the load on the secondary of the transformers be?

Is there a good website that explains this?

what is output impedance of a source follower mathematically?

thanks!

 

[theChris]

1/gm for small signal analysis

gm = (2 S Kpn Ids/n)^0.5 if memory serves at least.

but those specs probably aren't available. not sure how to mathmatically get them. maybe test it out with a common gate amplifier.

of course this doesn't count feedback which can lower output impedance.

 

[EWorkshop1708]

I wonder if you could use a toroid trans, but drive the CT secondary with the push pull, and either wind your other side yourself, for speaker impedance, or use the 120V primary to get a HV output to get either really loud speakers, or use on 70V line trans.