orange squeezer

[Hepcat]

Hello everyone,  I am pretty new to the  whole  DIY effects project world , I have built an alembic stratoblaster , just finished a green ringer.I am currently working on an orange squeezer, I followed the schematic at general guitar gadgets  , the one with external volume controlhttp://www.generalguitargadgets.com/pdf/ggg_osq_vol_lo.pdf
I followed the layout exactly using a pcb from ggg, I used 2n5457 for transistors and a tl072 for the IC. I also used sockets for the  transistors.  I have read alot on this forum on how subtle  the effect is , but as far as i can tell it is just boosting the signal, is this normal ? I dont really hear any compression. Here are the pinout readings

Q1-drain-9.12

     source-2.45

     gate-1.43

Q2-drain1.42

     source-1.43

     gate-0

IC- p1-8.52        p5-4.11
     p2-8.52        p6-4.98

     p3-0             p7-4.98
     p4-0             p8-9.11

The diode didnt measure any volts on either end .

Does any of this look normal? Thanks alot for any help   

[Hepcat]

Bump

[Rob Strand]

The voltages look OK to me.

Try adjusting the BIAS pot.

[Hepcat]

 Thanks Rob! I have tweaked the bias pot and tried many positions but still doesnt seem like its compressing. Maybe ill go back and check the pinouts again ,  shrug .

Thanks  -Josh-

[markm]

I'm having the same issue with a layout for the O/S that I'm working on.
Part of me thinks I may have a bum JFET, maybe U do 2?

[Rob Strand]

I doubt it's pin outs, the voltages wouldn't look right otherwise.

What JFET are you using?

[Hepcat]

 I am using the 2N 5457 JFET . Can someone reccomend some differnt ones ? Maybe ill try to swap them out and see if that changes the sound at all.

[Rob Strand]

The 2N5457's are usually OK but it's definitely worth trying another JFET, perhaps another 2N5457 first - maybe even swap the two in there.

Can you get the sound to cut-out by adjusting the BIAS pot?  That's a good sign the JFET is actually doing something.  At the cut-off point measure the source voltages on each JFET to get an idea of the JFET's cut-off voltage, if that is out of the norm it might explain why it's not working as well as it should.

I can't suggest any quick fixes but there's a few  other things you can do to help pin point any problems.  The first is to connect your multimeter to ground and the +Ve terminal of C7, set the multimeter to DC volts, play notes soft and loud. You should see this voltage go up when you play hard.  The other thing to try is to increase C7 to say 47uF.  This isn't a fix but what it does is lets your hear the very slow attack and release time, in other words it lets you hear the compressor working.   Lastly try pulling Q2 altogether, you should get quite a bit of boost perhaps with a bit of distortion as the opamp clips.

[Hepcat]

I finally got a chance to take another look at the squeezer couldnt find another set of 2n5457 so i used NTE 123a and got alot more boost but no compression , then i took out Q2 it actually sounded pretty nice but not what i think its supposed to  sound like. I changed C7 but it didnt make any noticeable difference. The voltage on the bottom pin of the trim pot measured 1.43 v  the other two measured zero , i have it set right where theres sound after no sound. I have made an audio probe and one thing im wondering about, if a circuit is working 100% will i be able to touch the probe to any pin in the circuit and make a connection? Thanks  -Josh-

[Hepcat]

oops , imeant I used NTE457 in replacement of the  2n5457.man its hard to keep all these numbers straight