How i can to increase the gain of ROG's Big Daddy?

[gigimarga]

Hello,

I discovered in a box a ROG's Big Daddy that i made some time ago. After i listened to it i understand why it was abandoned: less gain for my taste.

So, how i can to incease it's gain?

Thx a lot!

[GibsonGM]

you could try playing with the value of the source resistor on the JFET, but you might find you can't get enough drive with this particular circuit.  Try replacing it with a 1K in series with a 50K pot to dial around the amount of drive it will deliver....could work?

[gigimarga]

Thx...i will try to do what you said...i think to replace the FET booster with a Fetzer Valve, too.

[B Tremblay]

You can also increase the size of the 6n8 cap between the FET stage and 386.  This will pass more signal (in the form of lower frequencies) to overdrive the 386.

[gigimarga]

Thx a lot...i will try!

[gigimarga]

I replaced the FET stage with  a Fetzer Valve and it sounds very well (i replaced the 6.8nF cap with the 22nF of the Fetzer).
The only little problem is that if i play a long note, on the end, it's a short abrupt decay.
Why? The FET is properly biased...it's necessary to put a 100K trimpot (as a volume) before the input of the  386?

Thx a lot!