EHX Small Clone Vero not working

[freshmex18]

OK so now I am thoroughly confused.  Sometimes the circuit works as I mentioned above - no depth below 50% and loud clock ticking with the rate above 90%.  Then all of a sudden, the effect will stop working.  The clock ticking that is affected by the rate pot disappears completely.  If I turn the depth down to about 45%, the effect returns but with no rate ticking.  Turning the rate pot does nothing.  Other times, the effect stops working completely and all I get is clean signal.

I tried removing the 39k and the 4148 and putting the A100k pot back in and with an audio probe, I get signal at pins 7 and 8 of the MN3007.  Put the diode and the 39K back in and the effect works again.  Until it doesn't and the cycle continues.

Here are the new readings

Q1 5087

C 0
B 2.82
E 3.49

Q2 5088

C 8.87
B 2.82
E 5.16

Q3 5088

C 8.87
B 8.85
E 8.25

IC 1 4558

1 4.45
2 4.45
3 4.34
4 0
5 4.43
6 4.44
7 4.43
8 8.84


IC 2 MN3007

1 7.92
2 3.95
3 3.97
4 0
5 0
6 8.23
7 5.34
8 5.74

IC 3 CD4047BD

1 7.39
2 0
3 7.39
4 8.23
5 8.23
6 8.23
7 0
8 0
9 0
10 8.23
11 0
12 0
13 8.23
14 8.23

IC 4 LM348

1 7.23
2 7.23
3 7.15
4 0
5 0
6 8.23
7 7.85
8 7.9

[antonis]

Q2 5088

C 8.87
B 2.82
E 5.16

Not happy anymore..

[ElectricDruid]

Antonis is right about Q2.

There's one other thing that's weird in the voltages, which is that pin 1 of the MN3007 isn't the same as pins 4,5,6 and 14 of the 4047. They're supposed to be connected together directly!

It sounds like there's still something a bit odd with the LFO, what with the intermittant behaviour and ticking, but maybe lets try and fix these voltage issues before we go back to that.

[freshmex18]

Found the tiniest of solder bridges.  Reflowed and reknifed.  Circuit is back to working without crapping out (so far).  Depth knob only works from 9 o'clock on.  High pitched whine that matches the rate pot present at all positions of rate and depth knobs.  Placing a Klon in front of the pedal changes the pitch of the whine to a higher one and reduces the volume of the whine by about half.  It does not stop the ticking at max depth though.

I have discovered that turning the depth knob affects quite a few voltage readings

New voltages

Q1 5087

C 0
B 2.82
E 3.47

Q2 5088

C 8.85
B 4.09
E 3.52 with depth knob at min, fluctuating between 2.5-3.2 with depth knob at max

Q3 5088

C 8.84
B 8.7
E 7.96 with depth knob at min, fluctuating between 8.01-8.05 with depth knob at max

IC 1 4558

1 4.45
2 4.45
3 4.34
4 0
5 4.43
6 4.44
7 4.43
8 8.84


IC 2 MN3007

1 7.96 with depth knob at min, 8.05 with depth knob at max
2 3.97 with depth knob at min, 4.05 with depth knob at max
3 3.98
4 0
5 0
6 3.91 with depth knob at min, 4.01 with depth knob at max
7 4.14 with depth knob at min, fluctuating between 3.22-3.87 with depth knob at max
8 4.14 with depth knob at min, fluctuating between 3.22-3.87 with depth knob at max

IC 3 CD4047BD

1 5.17 with depth knob at min, fluctuating between 4.68-5.03 with depth knob at max
2 1.79 with depth knob at minimum, fluctuating between 0.5-1.23 with depth knob at max
3 5.16 with depth knob at min, fluctuating between 4.7-5.4 with depth knob at max
4 7.96 with depth knob at min, 8.03 with depth knob at max
5 7.96 with depth knob at min, 8.03 with depth knob at max
6 7.96 with depth knob at min, 8.03 with depth knob at max
7 0
8 0
9 0
10 3.96 with depth knob at min, 4.06 with depth knob at max
11 3.96 with depth knob at min, 4.06 with depth knob at max
12 0
13 6.47 with depth knob at min, fluctuating between 6.96-7.61 with depth knob at max
14 7.95 with depth knob at min, 8.03 with depth knob at max

IC 4 LM348

1 Fluctuating from 0 to 7.63
2 2.19
3 Fluctuating from 1.16 to 3.28
4 0
5 4.01
6 4.04
7 Fluctuating from 1.9 to 2.54
8 8.85

[duck_arse]

which is the depth pot, the one under the LM358 or the one under IC1A?

look at your vero/the layout [I'm not going to]. is the Q2 and Q3 collectors and the 180k [bottom left - nice one, a circuit with no designators] to +9V all sharing a same strip of copper?

[freshmex18]

The depth pot is the A10k under the LM358

The 100k is a trimmer

The 9V wire and the collector for Q2 share a copper strip.  A jumper connects that strip to the strip with the collector for Q3.  Another jumper connects that strip to the strip with the 180k