Well, silly me. The noise issue was apparently caused by one of my guitars! It has super high gain old Japanese single coils, and I guess the Mistress didn’t like it. I just tried it with my Strat and it’s much better. Go figure. Scruffie, thanks again for all your help and positive vibes.

Finally done with pesky work and back to what’s truly important. So, pins 2&3 on the 4558 were both 5.8v. Pins 9, 12, & 13 on the 4013 were all hovering around 6.85v. Does that seem right to you? I haven’t had time fool around with the pedal since the last time I posted, but I did notice something odd — when the bottom is off the pedal case and the pedal is upside down, I get a very clean signal. When the pedal is assembled and right side up, I hear a lot of gritty whoosh at one point in the sweep. I have several BBD flangers and this is noisier than normal.

Hey Scruffie, I had to order the 4013 — sorry for the delay. It freakin’ works! I still need to check the voltages to really be sure everything’s okay, but I put in the new flip-flop and a new 4558 and it flanges. It’s obviously noisy, but there’s also some grit in there that seems out of place. Any suggestions? Maybe a bad resistor? Anyway, I gotta do real work now, so I’ll post revised voltages later today. Woohoo!

Edit: this is with the old SAD1024 chip. Bonus!

This time I used the 18v wall wart instead of the batteries.

741

1) 0.1mv
2) 6.6v
3) 6.8v
4) 24mv
5) 5mv
6) 14.2v
7) 23v
8mv

4558

1) 6v
2) 10mv
3) 8mv
4) 0
5) 6v
6) 6.1v
7) 6.1v
14v

1024

1) 0
2) 6.1v
3) 3mv
4) .3mv
5) 14v
6) 3.4v
7) 14v
12v
9) 14v
10) 12v
11) 14v
12) 3.4v
13) 0.3mv
14) 3mv
15) 6.1v
16) 0

7611

1) 3.9v
2) 3.7v
3) 0.3mv
4) 8.2v
5) .3mv
6) 236mv
7) 0.4mv
0.4mv
9) 12v
10) 0.4mv
11) 7.1v
12) 12v
13) 5mv
14) 14v

339

1) 7.1v
2) 14v
3) 14v
4) 3.8v
5) 7.4v
6) 5.6v
7) 10.1v
97mv
9) 6.2v
10) 14v
11) 0.47v
12) 0.5mv
13) 235mv
14) 5.7v

Well, there’s voltage on all the ICs at least. How am I looking?

741

1) 0
2) 3.3v
3) 1.62v
4) 0
5) 0
6) 1.21v
7) 3.45v
1.6mv

4558

1) 1.4v
2) 1.4v
3) 1.35v
4) 0
5) 1.36v
6) 1.4v
7) 1.4v
3.3v

1024

1) 0
2) 1.5v
3) 1.7mv
4) 0
5) 3.59v
6) 0.1mv
7) 3.57v
0.42v
9) 3.6v
10) 0.42v
11) 3.57v
12) 0.1mv
13) 0
14) 3.2mv
15) 1.49v
16) 0

7611

1) 0.42v
2) 0.42v
3) 0
4) 2.09v
5) 0
6) 23mv
7) 0
0
9) 0.42v
10) 0
11) 2.14v
12) 0.44v
13) 3.4mv
14) 3.6v

339

1) 2v
2) 3.6v
3) 3.6v
4) 0.43v
5) 1.92v
6) 0.92v
7) 2.64v
25mv
9) 1.52v
10) 3.64v
11) 122mv
12) 0.1mv
13) 23mv
14) 0.92v

Hi Scruffie,

Woo hoo, progress! I made all the changes suggested, and now the pedal passes signal when engaged. No effect at any adjustment of the internal pots, but engaging the effect does cause a volume drop. I understand that’s a big complaint about these pedals, but right now it sounds pretty good.

Two questions: what should my next diagnostic step be? Should I go back through and check all the pins on all the ICs? The previous owner used a 12v power adapter with it — that’s what broke the pedal — but would that necessarily fry the SAD1024? I have a replacement, but I want to A. Be sure the old one is dead, and B. Be sure the rest of the circuit isn’t going to fry the new one.

Can I also just bitch about the incredible flimsiness of EHX boards? I’ve worked on a lot of old circuit boards, and traces break, come away from the substrate, etc., even on high quality products. But holy crap I only have to breathe on this board to destroy the traces!

Thanks!

Awessome. Looks like I have my work cut out for me! While I was waiting for your reply I FINALLY found a schematic. It wasn’t showing up in my searches.