45er no sound

Hello,

I have a problem with my 45er Phaser build. Bypass works but there’s no sound when the effect is engaged. I’ve checked the wiring and the solder joints, they all look good to me.

I’ve measured the following voltages on a DMM (referenced to ground):

BAT 8.96

Q1 G: 0.33 - 0.49 (changes constantly)
Q1 S: 0.25
Q1 D: 0.25

Q2 G: 0.36 - 0.52 (changes constantly)
Q2 S: 0.25
Q2 D: 0.25

IC1:

• Pin 1: 1.50
• Pin 2: 1.07
• Pin 3: 0.90
• Pin 4: 0.00
• Pin 5: 0.79
• Pin 6: 4.70
• Pin 7: 4.34
• Pin 8: 8.88

IC2:

• Pin 1: 5.06
• Pin 2: 2.67
• Pin 3: 1.18 (doesn’t vary with speed control)
• Pin 4: 0.00
• Pin 5: 3.23 - 5.39 (changes constantly)
• Pin 6: 3.69 - 5.55 (changes constantly)
• Pin 7: 1.23 - 8.23 (changes constantly)
• Pin 8: 8.88

C11, R16 & R21: around 8.84
D1: 0.24

So it looks like electricity is flowing through the circuit but the transistor values seem way too low and the IC values are incoherent. Does anybody know how to fix this?

Just a quick update, still puzzled by this.

I soldered every component again to make sure there weren’t any cold joints, but still no cigar. When I strum my guitar very loudly there’s a weak distorted signal getting through.

I tried swapping out the ICs for a pair of RC4558s. This resulted in a stronger but a nastily distorted signal way above unity gain. So I’m guessing the original TL072s should be okay. I also swapped the transistors for a non-matched 2N5457 pair but this had no effect whatsoever, so the FETs should be fine.

I also measured again, getting similar results, except for the following changes:
IC1 pin 5 now 0.24
IC1 pin 7 now 7.90
IC2 pin 1 now 7.89
IC2 pin 2 now 7.85
IC2 pin 3 now 0.24 (still doesn’t vary with the speed pot)

Here’s a couple of pics, the additional switch is an ”Univibe-switch” wired to C2 and C3 according to this GGG layout:
http://www.generalguitargadgets.com/pdf/ggg_p45_mods_lo.pdf

[Blockierte Grafik: https://i.postimg.cc/5bRt43cH/84-F19-A8-A-EF9-E-4077-9-AD8-6-FEF15-AEF699.jpg]

[Blockierte Grafik: https://i.postimg.cc/fTGZx8ZB/AAD2-B9-A1-FC11-4-A3-D-A328-2-C7-C9-EEF42-B7.jpg]

[Blockierte Grafik: https://i.postimg.cc/xdR2VYm4/CC0-FAE35-4347-492-A-B876-8-F042-CD56-FCA.jpg]

[Blockierte Grafik: https://i.postimg.cc/330xdv7t/EF71-D11-E-626-C-4-E6-C-A1-C2-2-CD3492-E0261.jpg]

EDIT: Managed to get bigger pics in, thanks for the tip cebersp

Okay, so one problem I've now noticed is the value of R24. It should be a 7k5 resistor but the kit came with an incorrect 75k resistor, which I've put in. Need to swap it out and see if it's the cause.

EDIT: And also Tr1 should be a 250k trimpot, but the kit was incorrectly supplied with a 250R trimpot. Need to swap this one out too.