# Phase II signal issues



## Stelloh42 (Jul 25, 2020)

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?


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## Stelloh42 (Jul 25, 2020)

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


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## Nostradoomus (Jul 25, 2020)

Post some pictures. Are you testing it in darkness?


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## Stelloh42 (Jul 25, 2020)

Nostradoomus said:


> 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?


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## Stelloh42 (Jul 25, 2020)

Nostradoomus said:


> Post some pictures. Are you testing it in darkness?


And will get some pics up after I redo the LDRs


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## Nostradoomus (Jul 25, 2020)

It should be pulsing, yes.


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## Stelloh42 (Jul 25, 2020)

Nostradoomus said:


> 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.


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## Nostradoomus (Jul 25, 2020)

Is the high pitched whine this frequency?


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## Stelloh42 (Jul 26, 2020)

Nostradoomus said:


> 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.


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## Nostradoomus (Jul 26, 2020)

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


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## Stelloh42 (Jul 26, 2020)

Nostradoomus said:


> 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.


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