Maxon 808 gain knob not working

[hyperliteBo]

Hello!

I built this effect: http://tagboardeffects.blogspot.be/2013/03/maxon-od808-reissue.html

Problem is that the gain pot is not working, it does absolutely nothing, tone and volume seems to be fine.
It also has a little bit of a stutter effect at the end of my tone ringing out like a fuzz that is running on lower voltages... But that's not too apparent.
Couple of thing I did different than the schematic:

-Used BC549C's instead of the sugested 2N5088, used the right orientation for the correct pinout.
-Used NE5532AP instead of a JRC4558D as IC
-Used a lead directly from the 9v input for my LED instead of de LED+ from the vero.

I checked:

-Shorts on my vero, none found.
-Wires from the vero to the pot
-The pot itself

I have built many pedals before and this is the first time I can't find the problem.

Here are pictures of my built and the measured voltages from the IC and transistors







Some thoughts? is the IC too different maybe??

Thnaks.
!

[Frank_NH]

Check pin 5 of the IC.  It should be close to the bias voltage (4.5 V) and not 1 V.  Check for a solder bridge in the vicinity.  Good luck!

[induction]

The main problem that I see is you are missing the 51k to the left of the IC. Without this resistor your gain pot is removed from the circuit and won't do anything.

Another problem is that it looks like you've subbed a 1M for the 1k near Q1. This will probably reduce your input volume quite a bit.

I don't understand the readings on pins 5-7 of the IC. Given the schematic, I don't see a way for the voltage on pin 5 to be so much lower than pin 6. Maybe it's a measurement error? After you fix the two resistors listed above, measure the voltages on the IC again.

[Frank_NH]

Good catches Induction.  May need a small 51k resistor to squeeze into the available space.  And yes make the corrections first before rechecking the IC voltages.