Small Stone - no phase effect

[taeagan]

Hello again.  I built a Small Stone board based on this layout:

http://tagboardeffects.blogspot.com/2016/05/electro-harmonix-small-stone.html

When I engage the effect I get no phasing.  I get a slight decrease in volume and tone.  In other words, I just get a slightly quiter, less trebley version of the bypassed signal.  Again, I've quadruple checked the layout, solder bridges, polarities, and so on.  Here are the voltages:

13700 chip on the top left:
1 - varies from 1.1v to 1.2v
2 - 3.6v
3 - 3v
4 - 3v
5 - 4.8v
6 - 0v
7 - 4.8v
8 - 3.6v
9 - 1.8v
10 - 2.8v
11 - 7.9v
12 - 2.8v
13 - 3v
14 - 3v
15 - 3.6v
16 - varies from 1.1v to 1.2v

13700 chip on the upper right hand:
1 - varies from 1.1v to 1.2v
2 - 3.5v
3 - 3v
4 - 2.9v
5 - 7.1v
6 - 0v
7 - 0v
8 - 1.3v
9 - 4.1v
10 - 5.3v
11 - 7.9v
12 - 5.3v
13 - 3v
14 - 3v
15 - 3.6v
16 - varies from 1.1 to 1.2v

LM324:
1 - 1.5v
2 - 3v
3 - 2.6v
4 - 7.8v
5 - 3v
6 - 3v
7 - 3v
8 - varies all over the place
9 - 3v
10 - 3v
11 - 0v
12 - varies from 0v to 3.4v
13 - varies from 2.1v to 2.4v
14 - varies all over the place

BC337:
E - 7.8v
B - 8.5v
C - 8.6v

This is another circuit that I just don't know really well, so I don't really know if these voltages are appropriate or not or where to start looking for the problem.  Appreciate the help.  

[Alex]

I haven't built it but the first thing I can see pin 5 & 7 of the upper right 13700 should have the same value.
Was it a writing mistake? Did you add the link?

[taeagan]

Thanks!  That certainly solved one problem, but not all of them.  I looked over the damn thing a million times and still missed that link.  I added it in, but now all I get out of it is a loud oscillation.  The speed control varies the speed of the oscillation, so something is trying to happen.  But now no signal from the guitar, just the sine wave type oscillation.  Any other ideas?  

[taeagan]

Anyone have any thoughts on why I'd get the oscillation in my output signal with nonew of the input signal? Thanks.

[Travis]

Does it change when you adjust the trimmer? Does it go away when switched out of the "color" mode?

[taeagan]

It stays with the switch in either position and the trimmer doesn't seem to have any appreciable effect. Frankly, from the schematic, I don't really understand this circuit all that well. What does the trimmer even do in this circuit?

[taeagan]

Some clarification...

The trimmer does have some minor effect.  If I crank it all of the way up, the volume of the oscillation increases.  For the first roughly 3/4 turn, there's no impact.  In that last quarter turn, it increases the volume of the oscillation.

The switch seems to increase the rate of the oscillation when the rate pot is turned up.  I didn't notice the switch having any impact when I had the rate pot turned all of the way down, but that could just be my lousy perception.  

Also, I am getting the dry signal through when I hook a guitar up and strike the strings.  It's like before - no phase effect, just the guitar signal with slightly less volume and treble.  

[taeagan]

OK, so here's another lead...

I have the board hooked up to my little test rig where I have an audio probe.  If I touch the lead of the audio probe to pins 1, 3, 4, 5, 10, or 11 of the LM324, the oscillation is gone and I get a decent sounding phase effect.  I'm totally at a loss because from what I can tell pin 4 is the +VDC on the chip and pin 11 is ground.  

[taeagan]

As I continue to troubleshoot this, I'm seeing something in the layout that doesn't make any sense as compared to the schematic.  Reading left to right and top to bottom, there's a link in column 13 that links rows 17 to 21.  Among other things, it links pin 2 of the LM324 to pin 6.  However, these two pins are not linked in the schematic (OP1A- and OP1B-):

http://s853.photobucket.com/user/bernardduur/media/Schematics/SmallTone.jpg.html

It would seem to me that there is a missing cut in the layout - right above the one in the very bottom row.  This would isolate pin 2 from pin 6.  Pins 6&7 would be linked and connected to the 1k resistor which goes to the 3u3 cap and out.  Pin 2 would then only be connected to the 15k and 18k resistors as in the schematic.

Can someone take a look and verify?  If I'm right, how would anyone have successfully built this?  

[Alex]

The cut is missing.
Don't know how it has been verified.
Should be ok now.
Did you try to add the cut?

[jghfslk]

I was also getting the oscillating noises.  I added the cut and now it seems to be working just fine.

[taeagan]

Yup, I added that cut and it sounds great!  Thanks for the help!

[realitycontrol]

Hey, I recently finished this board.
Was originally working from an old saved image of the layout without the cut and was receiving the oscillating siren noise.

Even after making the missing cut I am finding that I am receiving a similar oscillating sound with the pedal turned on.

If I take the input out the sound dies down to silence. As soon as I plug something in it starts again.
When I send a kick drum into the pedal it almost sounds as it the oscillation is resetting. Can get some funky effects out of it but I've definitely mucked up somewhere.

Should I start a new thread or post my voltages & images into this thread?

[realitycontrol]

Never mind.
I missed the 18k resistor connecting pins 1 and 2 of the LM324.
Working just fine now!