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Current Lover-clock noise?

Started by march500, February 17, 2015, 05:03:12 PM

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march500

I'm trying to deal with some faint but annoying high pitched clock noise. Seems to be an issue that comes up a bit with the more complex builds. I'm using the v3207 chip. I subbed a 560pF capacitor in place of the 680pF on the output of the chip just because I didn't on hand. Other than that I'm getting about 8.2 volts on pin 4 of the delay chip when the doc says it should be about 7.6v. I'm using a boss psu (9.6V) Would that account for the higher voltage or should that not matter?
One other question regarding the correction on the board at D4. Should it's lead be soldered just at C6/D5 junction or where the anode lead goes through the board as well. Right now I just have it terminated at C6/D5.
Thanks in advance to anyone who's got any hints.

march500

Checked out a earlier post in the forum and swapped in 47k resistor at R12 in place of the 82k... Did the trick. The high pitched whistle is gone! The substitution seemed to give a little more "play" in the bias trimmer. Note: I also put the proper capacitor in at C7.

luks999

Thats actually very helpful, thanks :)
actually i dont really have a noise, but the effect start sounding strange when the clock trimpot is turned up. so i left it nearly about fully counter-clockwise and im happy with the overall

thought the 82k has only effect on the bias? good to know :)

march500

I think it does just affect the bias but I couldn't dial in any decent sound before I swapped that resistor.