Stag3 a boost from guitarpcb

[whomeno]

I had built this one a few months ago. I did a rebuild on it. they call for a j113 trans. or a j201 is there any others that would give a little more boost?
Not sure how to tell by the data sheets
Thanks

[antonis]

It's called "Transconductance" (g_m) or "Forward transfer conductance" (g_fs) but I'm not sure if you'll manage to get more gain due to wide parameter spread, even among identical JFET types, in conjunction with small parameter variation among different JFET types..
(e.g. type X JFET may exhibit g_m of 4 - 6 mhos where type Y JFET may exhibit g_m of 3 - 5 mhos - you can easily choose type X for more gain and result in less gain in case of type X has an actual g_m of 4 mhos where type Y had an actual g_m of 5mhos..)

For a little more gain it should be helpful to raise a bit Drain resistor value..
(without significantly upsetting bias..)

P.S.
The above stand for grounded Source amp - if there is a Source resistor, you have to tweak R_Drain/R_Source ratio..