As the subject says.
I use SPIN CAD primarily for idea sketching. I'm looking to gain greater control over the envelope generation. I'm looking to use the pots to adjust the attack, release, and decay, but I would like to be able to program the range of each one in milliseconds.
Any suggestions?
Is it possible to adjust the behavior constants of the envelope generator?
Moderator: frank
-
Digital Larry
- Posts: 338
- Joined: Mon Nov 12, 2012 1:12 pm
- Contact:
Re: Is it possible to adjust the behavior constants of the envelope generator?
For reference, I have volunteered to answer ongoing questions about the use of SpinCAD over in the DSP section of diystompboxes.com.
At the moment, now that I look at it and dig deep into the recesses of my memory, the values shown for "Attack" and "Release" are actually the corner frequencies of the one pole low pass filters that do the enveloping. As such, the left side (which goes down to 0.51 Hz, the lowest corner frequency you can get without using extended precision techniques) is the slowest and the rate increases (rise time decreases) as you slide to the right. Given that these are really single pole low pass filters, they have an exponential response, so the "rise time" has to be defined as something we can all agree on such as 10% to 90%.
This article talks about analog filters but the concepts are the same.
https://www.signalintegrityjournal.com/ ... -rise-time
RT (rise time) = 0.35/(-3 db BW)
So at 0.51 Hz, the rise time would be expected to be 0.35/0.51 or about 0.69 seconds. You can probably make a spreadsheet which gives you the expected RT for various BW.
Now, have I measured it? No. But I think this is how it should work.
At the moment, now that I look at it and dig deep into the recesses of my memory, the values shown for "Attack" and "Release" are actually the corner frequencies of the one pole low pass filters that do the enveloping. As such, the left side (which goes down to 0.51 Hz, the lowest corner frequency you can get without using extended precision techniques) is the slowest and the rate increases (rise time decreases) as you slide to the right. Given that these are really single pole low pass filters, they have an exponential response, so the "rise time" has to be defined as something we can all agree on such as 10% to 90%.
This article talks about analog filters but the concepts are the same.
https://www.signalintegrityjournal.com/ ... -rise-time
RT (rise time) = 0.35/(-3 db BW)
So at 0.51 Hz, the rise time would be expected to be 0.35/0.51 or about 0.69 seconds. You can probably make a spreadsheet which gives you the expected RT for various BW.
Now, have I measured it? No. But I think this is how it should work.