Simple dist/od/fuzz-project

[HeimBrent]

Just for the fun of it, I threw this together the other night. Only problem is... It doesn't work like it should. Any ideas? The volume goes down when it is plugged in. I just put on the DC-jack, two audiojacks and the pots. No enclosure or switch.

The cirucut is the JFET-version here;
http://www.geocities.com/tpe123/folkurban/fuzz/gain.gif

Only difference is that I've used a 1M pot with a 1M resistor between the pot and ground.

...Help?

[foxfire]

are you sure the jfet's are in correctly? rylan

[HeimBrent]

The fact that the cirute distorts the sound like it shall made me belive they were.

[Jered]

  Remove the 1M pot and connect the input and 1M resistor directly to the JFEt gate. Does it sound any different now?
  Jered

[frankclarke]

Did you use J201's? The circuit works on my simulator.

[HeimBrent]

I used J201s. Probably just me wiring something wrong, I suspect. Haven't tried to skip the pot yet. I'll do that tonight.

Somebody know where I can find out what leg of the transistor that goes where? I have forgotten the name of the legs, as it is a few years since I last worked with this stuff. I am though pretty sure I've done it right. Looked at from the top, with the flat side up, the left one to ground, input in the middle and the one to the right goes on to the next cap...

Wait a sec. That might be where I went wrong. The second transistor might be put in wrong. I'll check that as well tonight. Gotta read some now. Exams tomorrow :/

[frequencycentral]

http://www.fairchildsemi.com/ds/J2/J201.pdf

[HeimBrent]

And, if I remember correctly, drain goes to ground, source is the signal in and gate is signal out?

[frequencycentral]

http://en.wikipedia.org/wiki/Field_effect_transistor

[Gus]

First
http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

Top down fet as drawn in the schematic  drain, gate, source
Is it the top right schematic at the link?

You can sub the 1 meg input volume pot for the 2 meg all that changes is the input resistance the circuit has.

That circuit is a two stage  circuit.  First stage has its drain bootstrapped (makes Rd look much bigger)

The second stage is a direct coupled source follower.

Now if the first stages drain is not in a "good" range the second stage will not be

What is the voltage at the drain and source of both J201s?  and what is the battery voltage?

[HeimBrent]

Aaahkey. The perfboard was such a mess that I gave up the whole project of debugging it, took a beer and startet all over. Now it works. More or less. Somethings fishy with the pots, like the fact that the volumepot works oposite of what it should, but heeey. I'll fix that when I rehouse it.