Trannies on Catalinbread Galileo MKII

[nickbungus]

Hi all.

Just a real quick question from a clueless idiot who likes to play with solder.

I've recently built a Catalinbread Galileo MKII but I cant source 5 MPF4393's as per the schematic.  So I did some reading about what would be suitable substitutes.  I have 4 Spare J201's, 4 Spare 2n5457's and a whole bunch of J112's.

Messing on with what I had, sometimes I had too much gain (sounding like DC noise), sometimes not enough but I wasn't nailing the sound and responses I've seen on YouTube.   I'm sure by playing some more I can get it right, but to get me in the right ballpark, can someone tell me what each of the transistors role is? 

Thanks

Heres the layout and schematic

[Cozybuilder]

Messing on with what I had, sometimes I had too much gain (sounding like DC noise), sometimes not enough but I wasn't nailing the sound and responses I've seen on YouTube.   I'm sure by playing some more I can get it right, but to get me in the right ballpark, can someone tell me what each of the transistors role is? 

Thanks

Heres the schematic

This is a Mu-amp setup. The P2N2222A is your first gain stage, feeding the first of 2 JFET Mu-amp stages. The 1M V-ref resistor setups in the schematic are inherently noisy- you might try a voltage divider with 2 10Ks instead, and feed that bias to each gate of the upper JFET in each Mu stage with separate 1M resistors instead, same with the final JFET (2M2 if you prefer). The last JFET is an output buffer. I'm surprised that this uses a 470p coupling cap between the Mu-amp stages- that will give a thin response. I would think either the J201s or the 2N5457 JFETs would work fine, you might need to adjust the bias at the drain, maybe 1K trimmers there. Hopefully someone else will chime in (J0K3RX?)

[armdnrdy]

Nick, if you PM me...I'll send you what you need.

[nickbungus]

Larry - I've said it before - You are a superstar!