Может что-то и меняется, но только не щёлчок
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Q: My tremulus lune that I built is clicking (or popping or ticking) to the rate of the LFO. Everything else works, but the clicking sound is annoying! What can I do?
A: First off, check, double check all your soldering. A simple bad joint can leave a filter cap out of circuit and cause this problem. Or a reversed electrolytic (blue cylinder) cap will do it too.
Next, try to locate the problem: put a 0.1uf cap temporarily across the gain pot (or gain trimpot). If the clicking goes away, then you've probably got high-frequency oscillation in the audio stage: (i.e. the problem is the photocell or the TL072 circuitry).
If it doesn't go away, its probably the LFO circuit or the powersupply (i.e. the 4558 or powersupply).
PROBLEM IN THE LFO CIRCUIT:
-Try replacing the 4558 IC.
-Try replacing the 10uF cap by the 4558.
-Try increasing the value of the LFO smoothing cap. It's the .0l uF (103) capacitor across pins 6 and 7 of the 4558. Go up to about .022 uF, .033 uF, or even .047 uF until the ticking goes away. The only thing with is that it will limit how fast the LFO can go. The waves kind of smear together at faster speeds.
-If the clicking only is heard when Smoothness is turned to square wave, then put a 0.01uF cap across Smoothness 1 and ground.
PROBLEM IN THE POWERSUPPLY:
If you're using a battery, try using a power adapter or vice versa.
If that doesn't work, then solder a 100 uF capacitor across the power supply rails directly underneath the 4558.
If you're using an external gain pot instead of a trimpot on the circuit board, try using a fixed resistor in the gain loop for higher than normal gain (try a 10K or a 22K at first), then control the volume with a 100K audio taper pot at the output.
PROBLEM IN THE AUDIO STAGE:
Do this test to see if it's the photocell:
Set your gain pot so that the output volume is close to the bypassed volume. Now take the pot out of the circuit and measure it with a meter. If it's between 10k and 100k then your photocell is probably OK.
If the meter shows less than 10k, then the second op-amp stage is getting loaded at the output too easily (at least thats what i think is happening, anybody understand?....) Or if the meter shows greater than 100k, the feedback loop is too high in resistance, and therefore invites oscillation too easily (Again, thats a guess as to whats happening...) In either case, replace the photocell.
Make sure you're using a TL072, not a lower grade opamp. The 4558 isn't critical, you can use a TL072 for that too.
Но оно похоже применимо только если щелчки постоянны.
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Если шумы я ещё готов потерпеть, в сравнении с полезным сигналом они не так заметны (да и в конце концов предполагал на что иду, собирая 9-вольтовый урезок), то резонансные пиканья раздражают.
