Schematic  http://www.tonepad.com/project.asp?id=4

1. No Sound at all.
2. Some component value deviates from prescribed because
   of unavailability (listed below)

         
Resistor    5.1m       Replaced With        5.6
Resistor    22m        Replaced With        10m
Resistor    240k       Replaced With        220k
Capacitor  10pF       Replaced With        12pF
Diode       1N914     Replaced With        1N4148

Notice that some replacements value where way lower,
but would that be a reason for it not to emit any sound at all?

If I had to I would say no. Just because the R's are so huge they're probably not involved directly in the signal path.
 Pin Voltages?

I would also guess the answer is no, but the 22M to 10M substitution is a little severe. You should still get some sound though. If you have them on hand, try using two 10M resistors in series for 20M. That should eliminate any substitution based problems. (using 10M there should just reduce your sweep sensitivity)

I would try audio probing it next.

On IC1 try pin 5, then 6, then 10, then 9, then 8, then 1, then 2, then 13.

To monitor IC2 you'll really need a scope for best results. You should be also to watch DC voltage follow your playing envelope in pins 13, then 12, then 11, then 10, but the rest of the pins have a high frequency PWM signal on them.

Oh one question...... are you using 4069UB chips?, or CMOS inverters with a "U" in the part number? I wouldn't expect it to work without unbuffered chips.

Best of luck getting it running! The MXR Envelope Filter is my absolute favorite purchased pedal.

Take care,
-Peter

I dont know how to use audio probe
as well as how to determine IC pin voltages.
Maybe you can provide me with a link so I can learn about them.


About the "U" in the part number, I have to check it out
when I get home. So if it doesnt have a "U" it wont make a sound?


I hope u guys hang on until I get this thing working.

Thanks a lot!

Here is the part number of the IC
  CD4069UBCN

  How can I test if an IC is busted?

Search for past threads about MXR envelope filter.
Once I read that Texas Instruments chips will not work with this device, expecially IC3.

Shit!!

one IC is a 4066....

I thought all of them are 4069

hmmm if nothing else is wrong, I may have a nice day tomorrow.

GOT IT!!!

its working now. I should have been careful in reading the parts list.

anyway, thanks guys for your help.

What'd you end up with for 'optos'?
 Audio probe is really just an amp input on a poker.
 take your cable, connect ground to the sleeve, wrap a wire to the tip, and poke the other end around in your powered circuit with some kind of input to it, so you can quickly find where the sound dies, [where it's getting lost in the circuit],