Click removal.
Hello everybody, I have just made an extremely simple scheme just to check how generators work and how can I apply them in future. Everything is fine, except for a very distinctly heard clicks at the beginning and at the end of the sound. Is there any way to eliminate those clicks? In a PC audio editor I would simply ensure that the generated segment starts and ends with zero points, but here I do not know what to do.
Follow up question, is there an fft filter in SS, like one in, say Adobe Audition? Which makes it possible to completely eliminate certain frequencies?
Skfir,
When I loaded your circuit, it switched a 1200Hz tone on and off (between 0 Hz and 1200 Hz), rather than shifting between two nonzero frequencies. When your 1 Hz square wave brings the VCO input to zero, the VCO "stops where it is" at a DC output somewhere in its sine wave. Perhaps this effect, shown below, is causing the audible clicks:
Assuming you wish to create a 50/50 on-off tone at a single frequency, you can avoid the clicks by running your VCO at the constant desired frequency, and instead using a "slew multiplexer" to switch the tone on and off. "Slew" devices in general are how to get rid of clicks in SigmaStudio. Typical results are shown below (amateur radio buffs would recognize this as a good RF envelope to minimize "key clicks").
I attached the circuit producing this envelope for reference, but there's many ways to do the same thing. You'll have more fun coming up with similar results yourself (while making and fixing the mistakes we all have gone through in the process).
BTW -- Sigma DSP is not set up for frequency-domain stuff like FFT, see https://ez.analog.com/docs/DOC-1671
Bob
Got it! So many ways to do the same thing, Thanks mate!
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