Need help on Dr. Quack, too

[sovtek50]

First of all, I can't thank You folks enough at this wonderful forum for sharing Your time and experience with each other. And no flaming! Are stompboxes builders better people??

Okay, so much for asskissing, now could somebody help me on my Dr. Quack. I tried to find info here in older posts, but nobody seemed to have had witnessed this ...
I built it, and it looks as if it should work, with one LED constantly on and the other one flashing according to input signal. But when I connect it to an amp, here's what happens: Depending on the position of the Norm/Bass-switch there's either just the dry sound and no quack, or just hiss with an almost inaudible quack. - Now, what could that be? All connections have been checked, they're okay. One thing is, I couldn't get hold of the right jfets here in Europe, as listed by Jack Orman, so first I tried  BF 245 B and then J201. Made no difference. Opamp is TL072, which should be okay, right?

[Travis]

http://www.muzique.com/schem/quack.gif

Is the switch wired correctly?  Mr. Orman was kind enough to include the switch wiring in his schematic.

Is Q2 oriented properly?  Voltage measurements on Q2 and the TL072 would help.

As long as the pinout is known/correct, the Fet used shouldn't matter.
Likewise, any dual opamp should work (the TL072 does work in this).

Your envelope detection is working (LED flashing); that is usually the most complicated part.

Otherwise, this sort of problem was made for the audio probe.

[R@bbiT]

Hey man I have the same problem with Quack. People told me that I have wired things wrong. I don't know if it is true but Todey I am going to rebuild my circuit using R G Keen's PCB. If my circuit will start to work then I will share my expierience  if not then I will seek for Info. But  that is interesting that u have similar  symptoms. I think I will get that Quack quacking.

[Travis]

Why not do the ROG/homewrecker Nurse Quacky?

[sovtek50]

Found it!! Damn.... it was just one little cap with a wrong value. I guess that's how You learn. Rabbit, check Your caps! Thanks for Your replies.
Of course I'll try the nurse quacky as well, like most of You DIYers, I'm helplessly addicted.