need some help with buff n' blend + muff fuzz pedal

[okuzster]

drain 9.61/9.62v
source 4.90v
gate 3.21v

got this values with 3 resistors, fet and cap (but cap is inactive?), like this, is it looks fine? do i get what you said right?



edit: put an in and out, there is no sound

[Kipper4]

Have you got your gate and source voltages mixed up?
Have you got them the right way round.
Double Check the pinout. I posted a link earlier.

I don't get why you are not getting a signal out though.
If you plug the guitar>input (C1) , Output >amp in.
But I'd still put a cap on th output to block dc. Say 50-100nf.


When you say the cap is inactive.
What do you mean?

Caps block dc so you should have 0v dc at the input. This is normal.
However as you have noted you should have you dc volts at the gate (jfet transistor input)

Sorry to keep harping on. I'd really like you to get it working mate.

[duck_arse]

your voltage numbers look about right, but as kipper says, probably on the wrong pins.

yes, 3 resistors fet and cap, is about the most basic test circuit you can make for fets (you only need add one resistor to prove gain is available), and yes the cap is inactive (for DC voltage).

please, go back and remeasure the voltages with no signal and nothing connecting to the output EXCEPT the 3k3, obviously. we'd expect those voltages, and on the right pins now. then connect whatever it is you are connecting to the output, and tell us what the voltage on the source does. again, remove the connected output, and tell us the voltage.

or post some photos of your setup.

[Kipper4]

I just simulated it on my crappy little sim no input=
D 9v
G 4v5
S 6v7


With a 1hz input
D 9v
G 4v5
S 3v1

[okuzster]

ok, checking again,

D 9v6
G 3v2
S 5v    with no input/output


D 9v5
G 3v2
S 5v  with bass guitar plugged to input (pulling G string) and output to 10w amplifier, i got sound from amplifier this time! fet values are not changed tho.

values are still same when i disconnect output.

i completed rest of it. i didnt get my pedal with me, so cant really test but looks like it's working now and i have no idea what i did different this time.

[Kipper4]

Excellant news, so now the buffers working you should be able to put the cap in as PPR suggested and wire the rest up and see if it suits your pedal/rig.
Glad its working

[duck_arse]

nicely done. now you know where the problem isn't, anything that crops up from here, you're half way home.