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I couldn't come up with any resolutions for the problems I had been experiencing, so I've convinced myself that I'm chasing snipe. The noise I was chasing is most noticeable with the sens turned ALL the way up, and the gate triggered, but nothing being played. I thinks it might be noise associated with the compression in the circuit, as had been previously stated. I'm calling this one done and taking it back to the owner. Thanks again, Scruffie. I really appreciate all your efforts.

Tim C in AZ

I finally got around to this, again.  I've got some NEW wonky voltages. IC7, IC9, Q2, and Q5 are my main focus. I've swapped in a new IC7, as I've got some bad voltages there. I don't have any 1458s for IC9, but they're on order. I'm not certain if Q5 is causing problems at IC9, or the other way around. I think I'll swap both Q2 and Q5 transistors when I put in the new 1458. I'm determined to get this pedal done this week. The owner has been extremely patient with me on this one, and I want to see what it can really do.

     Same as before, when it was "fixed" on the 15th. There's noise within only the effected portion of the signal. Bypassed sound and blended clean sound is completely free of the noise; the more effect is blended in, the more the noise is present. It's like a background low hum/rumble and a higher frequency buzz that's independent of the input signal frequency. The noise gets gated with the effect. Additionally, in comparison to another OG Attack Decay, this one sounds like it's always distorted. Edge and harmonics only make the distortion "messier." Unfortunately, I've found it hard to get a decent recording of the sound, though I tried to make it more prominent in the video from the 15th by futzing with the tone controls on my amp. I'll send you a link to the private video in PM so you can hear the stark difference between mine the the other persons AD.

     What's the possibility that a socket "goes bad", or isn't making good connection with all the pins on the IC? Is there a way to re-tension socket pins, like there is for tube sockets? Could it be a lead-dress issue in the pedal?

     Also, I just realized I had forgotten about the possible grounding issue, so I'll pull and re-set the in/out jacks in hopes that it makes a difference. I really think I'm just going to have to futz with it until I figure out where the issue is.

Yeah, I'm still struggling with this. The hass-alfed audio probe I made is far too noisy just from handling to be any good to me. It doesn't help that the amp itself is noisy and frequency limited. Regardless, I took new voltages with sense, blend, and attack around 30%, everything else at zero, and a 1k signal of .25v p-p on the input. I can't seem to do much with the info today. Too many superglue fumes, maybe? Q2 emitter V is way low. I pulled the part and tested it as good; replaced it with another with similar results. Hopefully tomorrow I'll be able to look at these voltages and my brain will do stuff.

Thank you, Scruffie. Plans for today changed when my GF said she won tickets to the first band she saw live, so I'm working on making that happen as smoothly as possible. I'll look at the AD tomorrow, hopefully for the last time.

A kind person in Japan sent me a private link of their working Attack Decay and it confirms that this one still needs some work. I think I'm going to have to build an audio probe to figure the rest of it out. I suspect it'll be easiest to just hack an old multimeter probe with an appropriate capacitor, but if anyone knows of some tricks for the "ultimate audio probe", I'm all ears. I'm considering building a +1000V probe as I've recently been given an AIMS VT-100 all tube PA amp, and I think voltages are over 600V in that beast.

    I guess I'll have to box it back up and see if I can get to a point where it feels like it's "done."
  Thank you so much, Scruffie. I would've NEVER suspected that coupling cap was bad and I would never have gotten to the point of suspecting it had you not talked me through the rest of the stuff.

   I'm not sure if it's fixed just yet, but it is doing SOMETHING! I wonder how much of the way this is working is part-and-parcel of the triggering circuit and how much of it is other things that have yet to be repaired. Is it possible that "hot" pickups would mess up the triggering? Sloppy playing messing up the trigger? Is it just a matter of setting all the knobs correctly?

   Around the 35sec mark of this first video, you can hear there is still quite a bit of hum in the background of the effect that is not at all present on the "clean side" of the blend pot.
https://www.facebook.com/100074733483188/videos/pcb.185448067289642/1071094436871915

The second video is essentially more of the same string slapping and knob twirling.
https://www.facebook.com/100074733483188/videos/pcb.185448067289642/765317831370852

I feel like there's more to do, but my expectations may be greater than the reality of what this pedal does. What do you think?

    Little by little, I seem to be eliminating unexpected problems. Scruffie was right in regards to changing my scope settings. Previously, I was trying to bias the 3007 from what I think is the timer noise from the 4047. I had thought that the low output from pin 7 of the 4885 was just a quirk of a circuit I still don't fully understand. Now that the coupling cap between the A/B sides of the 4558 has been replaced, I'm seeing that timer noise riding something that more resembles the waveform going into the 3007.

    It seems my signal at the 28/29/30 junction is low, or I've killed another 3080. Pics show the signal on pin 3 of the MN3007, junction of 28/29/30, (input)pin2 of the 3080, and (output) pin6 of the 3080. Obviously, the signal isn't coning out of IC11. I probed pin 3, seeing as this is a differential input, but there was nothing there. R55, R56, and C17 measure appropriately.

   After lunch, I'll try a different 3080 in the IC11 position.

Any input on what sort of signal strength I should be seeing at various parts of the circuit would be appreciated.

    I had to go back to square one.  It seems I have at least one bad cap upstream. I get solid signal at the input, pin 3 and pin 1 of the first 4558, and can see it shorting to ground on the wiper of the sense pot when turned to that extreme.

   Pin 5 of the 4558 has NO signal on it. But I do get a signal at the output pin 7. It seems the coupling cap is DEAD.(C2 on the RB schem) I verified the crappy new DMM with some other known good caps which read in spec. I guess more parts need to be ordered. I really miss having old-school RadioShack and Fry's Electronics stores to go to.

What signal am I seeing downstream from the 4558? Amplified noise? An OOP signal from the differential amplifier?

I'll check it out, but I'm not cam or mic equipped.

Any suggestions as to where I should have the various pots set at this point?

   I'm going to take a break from this project for the rest of the day. There's got to be an obvious problem that I'm missing and it's making me so frustrated that I doubt spending more time on it will be fruitful. I did swap out both the MN3007 and CD4047.

   Bias adjustment is changing voltage on pin 3, from near zero to -15.5-ish V. This appears correct based on the RB schematic. I checked the 4047 for the square wave signal from 10 and 11, which it has with a frequency near 36kHz, IIRC, but I couldn't find another probe to see both at the same time. With my cheap digital o-scope, the trigger function alters the phase, so it appears as if they are IN phase, as opposed to out of phase. There's probably a setting that will help me figure that out, but the broken English that the help-guide is written in is equally frustrating, as it often contradicts itself.

   None of the signals to or from the 3007 look any different than with the original IC. Attached is the "cleanest" signal I can get from pin 7 of the NEW 3007. This is at one extreme of the bias adjustment. It's more or less the same through 30% of the travel. From there, the waveform gets considerably more deformed. With the bias set somewhere in the middle, regardless of waveform, I can get the tiniest signal at the 28/29/30 junction, but it's totally swamped in noise that's an order of magnitude greater.

I'm kinda wishing I had a part-time plumbing job. I could go for some pre-construction demolition right about now.

   I started tracing this out this morning. It's noisy, but I've got signal up to pin 3 of the MN3007.

I had to back-track as there's nothing on the R28/29/30 junction. I also tracked further down-stream to verify any wonkiness; the 4.7Uf cap is oriented properly. Signal off of pin 7 of the MN3007 is all kinds of crappy, but I'm not certain what I'm supposed to be seeing. The following three images are from pin 7 of the 3007 with the bias at one extreme, centered, and the other extreme.

I thought I was dead in the water until I got another 3007, but then remembered I DID have another one of those, and a CD4047, to boot. I'm not really certain of their operational relationship, but figuring all that out likely won't benefit getting this pedal fixed. I've got the 2 new chips in, but found I had accidentally shut off my scope. I'm letting that warm back up now.  ...and now having to run out for the GF.

Does anyone know where to get replacement CTS pots with the appropriate stand-offs for this and other EHX pedals from the same era?

P.S. I'm hoping to figure out, this weekend, how to format my posts and pics how'd I like them to show. Many works in progress. :/

I've got a scope and sig gen. I'll dig into it tomorrow. Thanks again, Scruffie.