Cataclysm Delay -- No echo signal, but signal at input buffer and output buffer

[ItsASecret]

I've put together a Cataclysm delay and I'm currently getting no delay signal in my mix, and the pots dont seem to have any effect on anything.

The power looks good: I'm getting ~9Vdc direct from dc wall wart, 8.8Vdc on the op amp rails (I'm guessing thats after 0.2VDC drop from the shottky), my Vref is 4.4VDC (half my supply voltage), the PT2399 has a solid +5V on its power pin and pin 2 of the PT2399 is 2.45VDC (I believe that pin is expected to be half of the 5VDC supply voltage).

I've injected a sine wave so I could poke around with my scope, and here's what I'm seeing so far:

Sine wave is there across R1, and I'm seeing the same sine wave (centered around ~4.4V which is VREF) at the output of the first stage highlighted in yellow.



One I check past the coupling cap C7, the sine wave has disappeared, but I'm unsure why? It's basically no existent until you trace the circuit all the way past the final summing amp at the end of the circuit, where the sine wave is visible, pretty much untouched from the original input signal. I'll admit, I don't understand this circuit very well, so i might be missing something stupid. I've checked and rechecked my connections along that C7 path but everything looks good as far as I can tell.

 

[mcrowell75]

Long shot on an old thread. What was your solution? I’m having this issue too.

 

[Feral Feline]

It always makes me sad to see old threads come up where the OP received zero replies, let alone any help.


@mcrowell75 — Given that the OP here hasn't logged onto the forum for just over a year, I would suggest you start your own trouble-shooting thread, maybe throw in a link to this one, if you like. You are more likely to get help if others see the thread is not stagnant, but fresh.

INCLUDE: Well-lit pics of the FRONT & BACK of your build as well as all the wiring.

Cannot emphasize enough the WELL-LIT part of the equation, as that can determine the difference between ascertaining a red or brown colour-band on a resistor which may aid in the trouble-shoot. It's best to have the build UNBOXED (how else to photograph the non-component side of the board?).


I suspect you (and ItsASecret) have a short-to-ground in the delay path of your build(s). This would explain the dry signal getting through but no delay happening. Could be sloppy soldering such as a bridge, or cold solder-joint or ... make a
VISUAL INSPECTION OF ALL THE COMPONENTS IN THE DELAY PATH — are they the correct values? Are there any dodgy-looking solder-joints? Check with a continuity test between components, make sure there is continuity with related components' nets and make sure components that aren't supposed to go to ground are not going there.

A scrap of wire/solder/metal-shaving etc can get stuck under other components, such as an IC-Socket, making it very difficult to find a short, if there is one.

Anywayyyyy... enough here. Start your own thread and then post a link to it from this one. That way if anybody else has the problem, or better — a solution... they can find your thread.

Good Luck

FF