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... sorry...with IC2 and IC3 both removed I get clean dry signal in IC2 pin 16...and mute in pin 16 IC3...In fact I get clean dry signal in IC2 pin 16 with or without IC3 installed

I'll check again...

hi !
Removing both IC2 and IC3 I don't hear any signal at IC2 's pin 16...mute. With only IC2 removed I get clean signal in pin 16...
I don't know if this can help but I'm posting some pictures from the solder side...do I have to de-solder the delay pot to show a clearer view?





...looks messy but its only the flux...
Again, thank you for your patience...

So...
I put together a probe and I have done some testing...
With fdbk all the way down and delay and mix pot at noon, no ghost, mod and path engaged...

R8 : (C4 side) clean dry signal, (R41 side) mute
R21:(C29 side) Faint delay signal, (Out side) mute
R12: (C10 side) faint delay signal, (IC2 side) normal? Delay signal
R11: (C10 side) faint delay signal, (IC2 side) mute
R10: (C5 side) mute, (IC2 side) dry signal
R9: mute in both sides
R18: (C16 side) faint fuzzy signal, (IC3 side) distorted gated delay signal
R17: (R14 side) faint fuzzy signal, (IC3 side) muted (i guess, I forgot to note this one )
R16 : (IC3 side) delay signal
R15: (IC3 side) mute

...sides are taken from the layout. Not sure if I'm doing this right, In any case I'll do some more testing tomorrow...
Thank you !

thanks for your replies, I will check with an audio probe as soon as I build one and learn how to use it...
Just one detail :I have soldered a on-off-on switch for  "ghost" ...but I guess that that is not the source of the problem.

  sorry...I did not know what an audio probe was...all this years building effects, I guess I was just lucky...
Right now I'm reading RG's article on how to make (and use!) a probe.

I checked all resistors, nothing wrong here. I know that it is difficult to check a resistor value that's allready soldered in a circuit, but having another ZP working helped me to compare...I usually check all resistors with a multimeter before solder...the same with caps, so I was pretty sure that the problem wasn't there.

yes, r45 is omitted as noted in ZPSDX documentation update...
I'm checking resistors values one by one, but still not finding the source of this problem...

more pics, now with IC4 and R28 installed...(to many pictures? )

I hope this will help...









C18 is a 2n2 Panasonic's cap (I did not have any more boxed ones)
C22 and C11 were changed to electrolytic
IC4 (removed) has a 16 pin socket which I put by mistake, so R28 is socket ed (removed in the picture)...

I'm taking a few pictues right now...i'll post'em in 5 min.
Thank you again !

me again...
Let me try to explain a little better the problem...With feedback knob all the way down I get 1 repeat that sounds very distorted and gated, sounds allmost farty. Delay pot does work, it delays the farty sound and mix pot does what it does, increases the level of the flatulence  ...As i turn feedback up, that single farty repeat turns to a motorboarding sound...like a long fart...I can tell that modulation works to as I can hear that the noise (the farty sound) wobbles (and led indicator is blinking and varies as I turn up the rate pot).
Slam does work too.
As suggested, I removed one at the time ICs 5, 3 and 2. The noise stopped when I removed IC3...getting only dry signal.
I tried changing all ICs and transistors, change all caps around IC3, checking diodes and caps orientation, solder bridges...and nothing...Next step is, I guess,to remove pots to check if there is not something wrong under them (but I doubt it)...

With all this frustration I forgot to mention that the first one sounds awesome.

What should I check next?
In any case thank you for your help and your patience, I know is not easy to read such a complicated description from somebody that actually do not speaks English very well... (spell check does miracles)

update: the noise is gone when i remove IC 3
...audio probe..? way out of my skills 

sorry...i did not answer completely...With the Mix knob all the way down the noise disappears and my dry signal sounds fine...

Hi !!!
Yes, motorboarding in all settings. By the way the rate led works.
I allready checked for solder bridges, electrolytic caps orientation and everything seems fine...

Hi !
I'm Pierre, this is my first post here...but I was reading around for a while...
Yesterday I build my first Zero Point SDX which worked right away; as I had a spare board and enough parts to build another one, today I decided to do it. The only thing different with this one is the caps, I wanted to try some Wima caps to see if they would make any difference in the sound. This one don't work  
The sound is gated and there is an aw full motorboarding noise...I can tell true the noise that control knobs do what they are suppose to do, as well for the switches...

I have done some voltage readings in the IC's if it can help :

IC1
1  4.77v    5  9.54
2  4.77      6  4.78
3  4.75      7  4.78
4  0.01      8  4.15

IC2 and IC3 same readings
1  5.02        9  2.52
2  2.5         10  2.52
3  0.01       11  2.52
4  0.01       12  2.52
5  1.28       13  2.52
6  2.45       14  2.52
7  0.28       15  2.52
8  0.80       16  2.52

IC 4
1  4.77        8  4.77
2  4.77        9  4.77
3  4.68       10  4.75
4  9.54       11  0
5  2.34       12  4.75
6  4.77       13  4.77
7  4.77       14  4.77

IC 5
1 between 2 and 5?
2 4.77
3  4.54
4   0
5  9.54
6  between 2 and 7 ?
7  4.54
8  3.97

Any toughs?
Thank you !!!