Earthquaker Hummingbird Vero Problem

[cnspedalbuilder]

Hello, I built this circuit, which is verified at tagboard effects:
http://tagboardeffects.blogspot.com/2013/04/earthquaker-devices-hummingbird.html

Here is a schematic for it, but I am not sure it is accurate relative to the vero layout:
http://effectslayouts.blogspot.com/2015/10/earthquaker-devices-hummingbird.html

Here are photos:






You will notice that there are a couple of extra rows on top and one on the side. I kept those for a little breathing room in case I needed to hack the circuit. I tested the circuit before boxing, and all I get is the clean sound. Level pot adjusts the volume. Other pots and switch produce no audible effect.

My initial troubleshooting led to some more info:
-In another post, I learned that the 2n2646 is very finicky. Ron Neely II, being a badass, sent me another one that he tested on a couple of Vox repeat percussion circuits, so that's not the problem.
-Ron suggested that it the 2646 may be isolated from the rest of the circuit. Immediate continuity between the 2646 and connected components is good. Also, I verified that the toggle switch works as it shifts continuity b/w the 1uF and 4.7uF capacitors.
-Yes, the soldering looks ugly and I need to clean up a couple of spots--i am new to vero and making joints in those large holes is harder than my past PCB experiences. Still continuity tests along all the vero lines show separation at the cuts and continuity across the lines that are not cut. Also, there seems to be good continuity b/w transistor leads and socket pins.

-->Here are my only leads so far:
1. I did not have a 330k resistor, so I put a 220k and a 100k in series. The serial resistance checked out ~320 before installation, but on the board it tests more like 100k.

2. I tested the switch and pots. The resistance on the 25k depth pot only maxed out at about 13k. Also, when I tested the circuit, turning the pot led to weird changes in volume (normal at middle, drops toward both endpoints)

That's it. Anybody have the "GlenGarry leads"? 

I'm still early in the learning curve, so I won't be offended by simple suggestions.

[escapeplan]

Between the wiper and lug 3 on the depth pot is a 100k resistor, so the resistance there should only be about 20k when turned up. There may be some solder bridges causing you to see trouble also, causing that resistance to be even lower. As for the level pot, is the lead from lug 1 going to the top row near the collector for Q2? The level pot on this one acts like a typical voltage divider you'd see at the end of most circuits,  but here it's acting like a surrogate for the guitar volume knob at the front end, so that led me to think the leads may be hooked up wrong. The 330k resistor that you had to make from series resistors, looks like it may be physically touching the 22k resistor. Anything improved by moving those resistors out of the way? On Q1, are you sure you've got the pins oriented correctly? Hard to tell in the pic. I'll take a longer look when I have some time later.

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[cnspedalbuilder]

Between the wiper and lug 3 on the depth pot is a 100k resistor, so the resistance there should only be about 20k when turned up. There may be some solder bridges causing you to see trouble also, causing that resistance to be even lower. As for the level pot, is the lead from lug 1 going to the top row near the collector for Q2? The level pot on this one acts like a typical voltage divider you'd see at the end of most circuits,  but here it's acting like a surrogate for the guitar volume knob at the front end, so that led me to think the leads may be hooked up wrong. The 330k resistor that you had to make from series resistors, looks like it may be physically touching the 22k resistor. Anything improved by moving those resistors out of the way? On Q1, are you sure you've got the pins oriented correctly? Hard to tell in the pic. I'll take a longer look when I have some time later.

Thank you for your advice! The resistor effect is good to know. I guess that's there because they don't make 20k pots?

Solder bridges: I have not (yet) found continuity across the lines except those driven by the jumper or by the mode switch. within lines, I see continuity everywhere that is on the same continuous line, not on opposite sites of a hole, though. It's certain that the solder joints bridge across components on the same line, but that's okay, right?

Volume pot: I will double check, but both the layout and schematic show that input goes straight to level pot and signal from the pot goes to the board. I agree it's weird, it would seem like a better idea to adjust level at the end. 

other stuff:I'm not sure q1 is oriented correctly, but effect doesn't work when I flip around the transistor either. That seems to go with theory that Q1 is somehow isolated from circuit. The series resistors are above the 22K, it's just hard to see from the top view. I can take better pictures of the top of the board if it would help.

I've not yet checked the pot wiring and I rushed those joints. Is it possible a bad joint on a pot lug could disconnect Q1 from the circuit?

BTW, your pedal site is cool, and I love the logo. Reminds me of DRI back in my hardcore days.

[escapeplan]

Between the wiper and lug 3 on the depth pot is a 100k resistor, so the resistance there should only be about 20k when turned up. There may be some solder bridges causing you to see trouble also, causing that resistance to be even lower. As for the level pot, is the lead from lug 1 going to the top row near the collector for Q2? The level pot on this one acts like a typical voltage divider you'd see at the end of most circuits,  but here it's acting like a surrogate for the guitar volume knob at the front end, so that led me to think the leads may be hooked up wrong. The 330k resistor that you had to make from series resistors, looks like it may be physically touching the 22k resistor. Anything improved by moving those resistors out of the way? On Q1, are you sure you've got the pins oriented correctly? Hard to tell in the pic. I'll take a longer look when I have some time later.

Thank you for your advice! The resistor effect is good to know. I guess that's there because they don't make 20k pots?

Solder bridges: I have not (yet) found continuity across the lines except those driven by the jumper or by the mode switch. within lines, I see continuity everywhere that is on the same continuous line, not on opposite sites of a hole, though. It's certain that the solder joints bridge across components on the same line, but that's okay, right?

Volume pot: I will double check, but both the layout and schematic show that input goes straight to level pot and signal from the pot goes to the board. I agree it's weird, it would seem like a better idea to adjust level at the end. 

other stuff:I'm not sure q1 is oriented correctly, but effect doesn't work when I flip around the transistor either. That seems to go with theory that Q1 is somehow isolated from circuit. The series resistors are above the 22K, it's just hard to see from the top view. I can take better pictures of the top of the board if it would help.

I've not yet checked the pot wiring and I rushed those joints. Is it possible a bad joint on a pot lug could disconnect Q1 from the circuit?

BTW, your pedal site is cool, and I love the logo. Reminds me of DRI back in my hardcore days.

Lol, thanks, I didn't even think of the DRI logo until after I had started using mine. My punk buddies made the same comment. Lemme go back through your pics zoomed in and see is I see anything.

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[escapeplan]

I printed out the layout and compared to your pics. It looks like your cuts and all the components I could see were in the right place. Orientation of the jfet looks good. That, coupled with the fact that you're getting clean sound and the depth pot acting weird tells me that there has to be a short somewhere, a weird value resistor somewhere, or you've got a bad ujt. When you turn down the rate pot, still no luck? I'm wondering if the ujt is locked up. If working properly, you should see a build of voltage in the 1uf or the 4.7uf (depending on the switch) and when it exceeds the threshold for the emitter and base 1 to start conducting, it unloads the cap through the 39R resistor to ground. Once the cap is discharged, the e/b1 junction stops conducting, process starts again, thus the attack envelope generated by the design. There's a chance that a higher resistance where the 27k resistor is can get things rolling if the emitter junction isn't closing.Tab poking up like in your pic should be correct orientation for the 2n2646. Apparently the 2646's are finicky. Check out this site and test your ujt. www.sentex.ca/~mec1995/gadgets/ujttest.htm

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[cnspedalbuilder]

Andy, Your explanation of the circuit is super helpful. I am having trouble getting good resistance measurements wth my DMM, I think I need to replace the leads. I have tested the UJT with my transistor testor, and it reads 2 Diodes: 2->1 1.05V, 2->3 970mV. I got this UJT from theehman (ron neely II) and he tested them in the repeat percussion pedals that he builds. So I think it's good, but will retest with a voltmeter. Also will check out the capacitor voltages.

I also went through the circuit with an audio probe. What I found was that sound does not make it from input to the 2n2646. It seems to go from the path from level pot->22k->2n5457 (Q3)-> 2.2uF (C3)-->Output. Sound gets to depth and level pots but not to rate. I can get sound from Emitter at 2n5089 (Q2) but nothing from Base or Collector or from anything that is on those lines.

Another notable thing was that there is a 100k that runs from line 3 to Ground rail and another from line 4 to ground rail. Both show sound on the top side but no sound on the ground side.

Most important, I do not get sound in any part of the circuit that runs to/from the 2646.

I don't know if it's supposed to be like this or even if the audio probe is useful for this problem, but I thought I would check to see.

Thanks for your help!

[cnspedalbuilder]

Happy Independence Day. I was wondering if anyone could give me some info on voltages. I've ruled out transistor failure and I'm fairly certain that the UJT part of the circuit is not modulating the output. I'm trying to diagnose where the problem is. Audio probe info is above, and I can record voltages if someone can tell me where to check. Depth pot perhaps?

OK, I think I fixed the problem! Somehow there was a break in the path from UJT Emitter to the 5089 Base. I re-did everything along that line and subbed a 300k for the 220k+100k serial setup and it now works from the board. Thanks @theehman @escapeplan for your help!!!!!!