Help Debugging Phase 90 clone, Pez 90.

[Micahnormal]

Hello all. Once again, thanks for the wealth of information on this board so far. I've only started building effects recently with the first three all successes thanks to all the info on here.
The fourth pedal, said Pez 90, is proving to be a little more difficult. I've tried going over it a few times looking for something I missed (solder bridge, dry solder, etc), and I think it's time for me to get some fresh hive mind "eyes" to give it a look. All the info is below, and let me know if there is more info that would be helpful. Thanks!

1.What does it do, not do, and sound like? For starters, there is sound in the bypass mode. I used 3DPT for true bypass, so I get the dry signal, but there is an oscillating hum. Tweaking the trim pot seems to change the frequency of the hum. When the effect is engaged, LED come on, no dry signal, just a very loud oscillating hum. Tweaking the trimpot changes frequency of the hum, turning the "rate" knob changes how fast the hum oscillates.

2.Name of the circuit =  Tonepad's Pez 90 / MXR Phase 90 clone

3.Source of the circuit (URL of schematic or project) = http://www.tonepad.com/getFile.asp?id=42

4.Any modifications to the circuit? No

5.Any parts substitutions? My 250k trim pot looks different than the typical square box ones I've seen...has large bent pins instead of the normal small straight legs/pins and sits up off the circuit board when in place.  And, not that it matters, but I used a stereo output jack instead of mono. Other than that, none.

6.Positive ground to negative ground conversion? No

7. What is the out of circuit battery voltage? =>  8.74
Voltage at the circuit board end of the red battery lead = 8.72
Voltage at the circuit board end of the black battery lead = 0.00


Q1
G=1.55
S=4.24
D=5.24

Q2
G=1.60
S=4.24
D=4.76

Q3
G=1.54
S=4.24
D=4.25

Q4
G =1.55
S =4.25   
D=4.25      

Q5 – The 2N4125
G=4.24
S=3.90
D=3.08


IC1
P1 4.26
P2 4.26
P3 2.87
P4 0.00
P5 3.19
P6 4.41
P7 8.08 –but jumps between 1.XX to 8.08
P8 8.73

IC2
P1 4.25
P2 4.25
P3 4.25
P4 0.00
P5 4.25
P6 4.25
P7 4.25
P8 8.70

IC3
P1 5.24
P2 4.74
P3 4.75
P4 0.00
P5 5.2X changes
P6 5.2X
P7 4.3X
P8 8.70

D1
A (anode, the non-band end) = 8.67
K (cathode, the banded end) = 0.00

Z1 (zener)
A = 4.24
K = 0.00

[Micahnormal]

Ok, I see exactly why this debugging process is the way it is...lol. It's to cause guys like me to look over the circuit so closely that we catch the *ahem* solder bridge we missed. Hum is gone and and the pedal works like it "should" with one remaining issue. The treble and volume boost with this pedal is pretty noticeable. Is that normal for this circuit? Adjusting the trim pot helps, but when its adjusted so that there is no treble boost, the effect is gone. When the trim pot is adjusted so that the effect is audible, there is a significant treble boost (kind of like switching to the bridge pickup from neck). Anyone have any ideas?

[Govmnt_Lacky]

Double check your cap values on your non-polarized caps. Especially the input and output caps.

Also, check your electrolytic/polarized cap values and orientation. I have built several 90's and none of them exhibited a Treble/Volume boost.

Good Luck 

[Micahnormal]

Thanks. I will do that. I used a 10uf and 4.7uf together in parallel for the 15uf Cap. Any way that could cause the problem?

[Govmnt_Lacky]

Thanks. I will do that. I used a 10uf and 4.7uf together in parallel for the 15uf Cap. Any way that could cause the problem?

Gotta look 

Definitely check the orientation to make sure that you put the positive sides together and the negative sides together.

Might not hurt to double check resistor values as well.

[Fender3D]

Ic 3 should have similar readings as Ic2, check around pin 4,5,6 (maybe Q4)

[Micahnormal]

Ic 3 should have similar readings as Ic2, check around pin 4,5,6 (maybe Q4)

Exactly where my solder bridge was. The readings now are similar to IC2. Still having the treble boost with slight volume boost. Would it help for me to post new values?

[R.G.]

Exactly where my solder bridge was. The readings now are similar to IC2. Still having the treble boost with slight volume boost. Would it help for me to post new values?

Yes.

[Micahnormal]

Ok, here are the new voltages. Just to clarify the circuit does work and has phasing effect, but with a treble boost similar to switching to bridge pickup from neck...and, when I actually switch to bridge pickup, the treble boost is significant enough to cause slight high end distortion. Thanks for the help!

7. What is the out of circuit battery voltage? =>  8.79
Voltage at the circuit board end of the red battery lead = 8.79
Voltage at the circuit board end of the black battery lead = 0.00


Q1
G=1.42
S=4.32
D=4.31

Q2
G=1.42
S=4.32
D=4.32

Q3
G=1.42
S=4.32
D=4.32

Q4
G =1.42
S =4.32   
D=4.32      

Q5 – The 2N4125
G=4.32
S=3.72
D=2.50


IC1
P1 4.32
P2 4.32
P3 2.91
P4 0.00
P5 3.83
P6 4.30-4.50 (changes slightly)
P7 3.70-5.0 (changes)
P8 8.73

IC2
P1 4.32
P2 4.32
P3 4.30
P4 0.00
P5 4.31
P6 4.32
P7 4.32
P8 8.70

IC3
P1 4.32
P2 4.46
P3 4.31
P4 0.00
P5 4.31
P6 4.64
P7 4.32
P8 8.68

D1
A (anode, the non-band end) = 8.67
K (cathode, the banded end) = 0.00

Z1 (zener)
A = 4.31
K = 0.00