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Re: A-127 Triple VCRF calibration procedure

2011-04-20 by Tim

> The exact measuring procedure is a bit more complex for filters that do not
> have available self-oscillation. You need a measurement equipment that gives
> you the frequency response of the filter and how it changes with the control
> voltage (combination of a frequency modulated sine wave over the audio range
> as audio signal and an envelope follower at the filter output which gives
> you the filter response curve).

Yes, I have been doing this manually, because of that lack of self-oscillation!

> After that the absolute frequency
> of the filter is adjusted to the desired value (i.e. the frequency if all CV
> inputs are zero Volt and the manual control is fully CCW).

It is what these values are for the factory setup-up of the A-127 that I was really wondering about - e.g. is the cut-off range set to 8 -> 4096Hz, or 16 -> 8192, or 32 -> 16384 or ... what?

Thanks again,
Tim

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