Phase II signal issues

[Stelloh42]

Okay - so I just built up a Phase II phaser and it turns on, passes signal in bypass, etc. I subbed a couple of parts since Tayda was out of A25k pc mount pots, so I used an A50k for the rate knob and they were also out of TC1044 voltage ICs, so I used an ICL7660 instead. When the effect is engaged, there is only a subtle hint of phase and the internal yellow LED doesn't seem to pulse at any rate no matter how I set the trim pots or turn the rate knob. Also - when the rate knob is maxed, there is a high pitched whine.
Any ideas on what might be causing this?

 

[Stelloh42]

Also - I definitely didn't attach the LDRs at the right angle. Going to need to redo those. Just looked at another post regarding that and I need to get mine closer to the LED

 

[Nostradoomus]

Post some pictures. Are you testing it in darkness?

 

[Stelloh42]

Post some pictures. Are you testing it in darkness?

There is some light contamination happening with the status LED and the LDRs. I'm going to re-angle them so they are closer to the yellow LED and then cover them so there is no outside light interference. This is my first build with LDRs - do you know if the yellow LED is supposed to pulse visibly?

 

[Stelloh42]

Post some pictures. Are you testing it in darkness?

And will get some pics up after I redo the LDRs

 

[Nostradoomus]

It should be pulsing, yes.

 

[Stelloh42]

It should be pulsing, yes.

Thanks - the only variation in the brightness comes from adjusting the trimmer that controls it. The external pots don't affect it all. So I'm going to check all my part values. I also have the right voltage regulator IC on the way. I'll post here if I get the issue solved. Thanks again.

 

[Nostradoomus]

Is the high pitched whine this frequency?

 

[Stelloh42]

Is the high pitched whine this frequency?

It is - and it drops off when I roll the rate knob all the way down, which is really the only evidence that the pot is doing anything.

 

[Nostradoomus]

Well that just shows you’ve got a dodgy charge pump chip...doesn’t explain the rest!

 

[Stelloh42]

Well that just shows you’ve got a dodgy charge pump chip...doesn’t explain the rest!

Yeah - that one is IC7 - one of the two parts that I sub'd - I seem to recall reading somewhere that the chip I used can do this. The correct one from the BOM is on the way and I'll start running down all the other issues once I get that one sorted. Thanks again.