x0x:envelopemods
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x0x:envelopemods [2007/10/26 10:00] mat_s correction of "Gate On Forever", addition of "VCA Envelope On Forever" |
x0x:envelopemods [2016/01/28 18:05] (current) |
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| The self-described accent sweep circuit in the devilfish 303 it not as simple as what I described below. There are a few things going on. First, there is a buffer circuit inserted in line between D24(+) and the junction of D24(+)/VR7-PIN2/R119 (however you can do it without the need for the opamp or any buffer). Also, depending on the mode, fast, normal, or slow there is a cap or cap+resistor placed in line with C13. Simply changing C13 does work but there is an inherent change in the overall amount of the envelope sweep signal if this change is not compensated for. For example, with the stock setup with accent all the way up and resonance all the way up and C13 at the stock value of 1uF the accent sweep may peak at 6v - giving a big change in cutoff frequency If C13 is increased to make the sweep speed slower the sweep may peak now at only 3v, for example, if level change is not also compensated for. | The self-described accent sweep circuit in the devilfish 303 it not as simple as what I described below. There are a few things going on. First, there is a buffer circuit inserted in line between D24(+) and the junction of D24(+)/VR7-PIN2/R119 (however you can do it without the need for the opamp or any buffer). Also, depending on the mode, fast, normal, or slow there is a cap or cap+resistor placed in line with C13. Simply changing C13 does work but there is an inherent change in the overall amount of the envelope sweep signal if this change is not compensated for. For example, with the stock setup with accent all the way up and resonance all the way up and C13 at the stock value of 1uF the accent sweep may peak at 6v - giving a big change in cutoff frequency If C13 is increased to make the sweep speed slower the sweep may peak now at only 3v, for example, if level change is not also compensated for. | ||
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| ==== Accent Sweep Speed ==== | ==== Accent Sweep Speed ==== | ||
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| |to TB303 ground | |to TB303 ground | ||
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| + | NOTE: the solution above is quite elegant and has the lowest parts count BUT you save exactly ONE capacitor. Since caps are cheap I suggest to use 3 caps - this way you can try different cap values until you get a combination that you like. I used a 0.47uF cap for FAST, the stock 1uF for NORMAL and a 100uf (!!) for SLOW. The somewhat high value for the SLOW cap makes for a quite interesting effect: the cap gets charged by consecutive "accent bursts" and the accent goes higher and higher and higher with each new hit over a long timeframe (it takes ~10 seconds to reach its peak!!). Nice if you also increased the Accent range! | ||
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| CategoryMods | CategoryMods | ||
/home/ladyada/public_html/wiki/data/pages/x0x/envelopemods.txt · Last modified: 2016/01/28 18:05 (external edit)
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