debugging zombie chorus, help very appreciated

[lopsided]

Hi guys,

I'm building the zombie chorus but it doesn't chorus. As a relatively newbie builder I assume my MN3007 might be broken , but I know it's often a false assumption. So I would really appreciate anyone more experience taking a look at my problem.

Effect type: Zombie Chorus from this schematics http://www.geofex.com/PCB_layouts/Layouts/zombie.pdf . I do it on perfboard using the layout from the galleries, but I've corrected the various mistakes, so now it's just like the schematics.

Effect problem: First I didn't get no sound at all. Then I've noticed a bad connection from U1 op-amp to ground so I've corrected it. Now I'm getting sound but no chorus at all.

What I've tried: Dubblechecked the schematics to layout to perfboard conversion and did not find any other mistakes. I know they sometimes appear, when you check it for tenth time, but for now I'm assuming I'm having it right.

Did an audioprobe. The audio signal goes through the first opamp to the 3rd pin of the MN3007 but doesn't go out from the 7th. I can hear a noticeable pulse on the pin 6 of th MN3007 reacting on the speed and depth pots. It's just a pulse no real audio signal (similar to a pulse tube tremolo in my combo does, when just turned on but with completely pulled down volume).

The voltage on th MN3007 is
1 - 9,14
2 - 4,53
3 - 5,50
4 - 0
5 - 0
6 - 4,58
7 and 8 behave in a way i don't understand, when I've measured them they had 4,12 but slowly raisin in about 0,01V per second way over 5V. when I unplugged the battery and plugged it again it took on from where it stopped. Next time I measured it was bellow actually bellow 4 and raising. I believe this isn't normal.

My hypothesis : From the pulse coming from the 4046, which is reacting on the pots, i conclude that the lower half of the schematics works correctly. (I know this does not necessarily need to be so; I am not quite sure if the audio signal is not supposed to go through the 4046 too , ).
So the problem is supposed to be in the MN3007 or somewhere in it's neighborhood.
Could the notgrounded opamp when i first powered the circuit damage the MN3007?

I'm going to check the whole thing again this evening, but if anyone had a useful thought on this in the meantime, I would be very grateful.

Thanks a lot!

l_s

[lopsided]

so I have spent three evenings looking and the circuit and haven't found a mistake. so I gave up an ordered another MN3007. I think I'm going to find the problem now .
It will either work with the new IC or I'll have a spare chip for my future builds and the certainty that the problem is elsewhere.
If anyone had another idea what might be wrong I'd still appreciate it.

l_s

[wakeuptone]

I built one but no sound at all.  I check U1 is function and had signal on Pin 1, 7  I'm also suspect U2 (MN3007) out of order too.  I will find the new MN3007 and try it

[wakeuptone]

Ok.. I found my error.  U3 pin 4 does not ground.  

Now, it's working but Depth and Speed not enough and ticking sound when speed at max.  I will deticking per http://hammer.ampage.org/?cmd=lt&xid=&fid=&ex=&pg=4

[lopsided]

so I've got a new chip yesterday. Tried it and it works! Wonder if my first chip was broken or if i damaged it by not grounding the opamp, when i first powered the circuit.
Speed and depth seems just alright for me. Actually I find only the first half of the speed and the second half of the depth pot useful for me, but I am getting quiet what I was hoping for.
As for the infamous ticking. I have tested the circuit only on my small home solid state. When my computer was off I've heard no ticking at all. When I turned on the comp I got some ticking but only when I wasn't grounded. When i have touched the strings the ticking as much as disappeared. Let's see how it's going to behave at the rehearsal in a room full of amps. Maybe then I'll look for the deticking mod.

l_s