Please help me troubleshoot Dr. Boogey [no sound]

[aloupos]

Just finished building Dr. Boogey, and I'm not getting audio through the various gain stages.  I have the following values at the fets, which are obviously off.  I'm using the siliconix J201's from smallbear, although the part  number on them is different from the siliconix datasheet I use as a reference.  For this reason (ambigious pinouts), I've reversed the fets but still don't have results.  Here are the #'s: 

Supply: Clean 8.5 provided by voodoo lab pedal power'

Q1
D: 4 - 4.5 (unstable)
S: 4
G: 4


Q2
D: 4.5
S: 3.9
G: 3.9


Q3
D: 4.5
S: 4
G: 4


Q4
D: 8
S: 7.5
G: 7.5


Q5      (Moving the bias trimpot has little effect on the drain, except to move it between 8-8.5 at the top eight of the pot. 
D: 8.5
S: 8.1
G: 8.1

Are these results indicative of reversed fets?   

Using an audio probe, I have audio at Q1 at the gate and drain, although it's not obvious if it's being amplified or not.  At Q2 and >, I have no audio.  I've been over this circuit a few dozen times, and have hacked the poor thing to death but still no dice.  Any help really really apreciated.

[aloupos]

OK, definately my fets were reversed, and also likely damaged -- I replaced them with new fets, and now using an audio signal I have amplification at the first and second fets.  The third I have signal at the gate and then a sound a little like mids at the drain .. very cool using an audio probe!

Here are the updated values: 

Q1
D: 4.5 stable
S: 1
G: .2

Q2
D: 4.5
S: 2
G: .1


Q3
D: 5.8
S: 1.8
G: .2


Q4
D: 4.5
S: 3.2
G: 0


Q5
D: 8.5
S: 4
G: 4.5

[Xavier]

All I can say according to my own experience is:

-Double check your component values, specially at eq sections. It's very easy to swap a 470R resistor by a 470K, believe me. Also the cap values

-Double check all your gain stages (caps and resistors REALLY to ground from the source)

-Double check the component placement. One hole up from where it should can make a difference.

basically, don't get frustrated and double check methodically. Voltage at the drains, signal at the gates. If you don't have signal at the output, go back component by component with the audio probe, until you find the problem.

This also is a reminder for myself

[aloupos]

I notice at the fifth stage, they tie gain to drain and the voltage from trimpot 4.  Is this correct? 

Is it normal that I have strange values (as above) on the 5th fet?  I'm going to try replacing this fet next. 

Thanks Xavier ... I did actually find two misplaced resisters