Good post Nathan. You may be right about the CZ's envelopes being linear. I had forgotten about the CZ manual describing the rates as angles. Just out of curiosity what book about synth construction are you quoting from? I'm a synth book junky and I don't think that I've ever read a book that had any really detailed discussion about envelopes. If the rates are really angles then the time relationships would still not be linear as the elapsed time between two envelope stages would be given by: (L2-L1)/Tan(R). For a level change of 100 the time taken for angles 10~90 (in degrees) would look something like: Level Rate Angle Time 100 10 567.13 100 20 274.75 100 30 173.21 100 40 119.18 100 50 83.91 100 60 57.74 100 70 36.40 100 80 17.63 100 90 0.00 There you can see that none of the time values are multiples which they would have to be in order for linearity. Once again if the rates really are angles your envelope matching formulas would have to change to use the Level/Tan(R) calculation rather than the Level/Rate calculation. Thanks to you too for the excellent discussion! Jon -----Original Message----- From: Nathan I Smutz [SMTP:n.smutz@...] Sent: Monday, March 25, 2002 8:20 PM To: CZsynth@yahoogroups.com Subject: Re: [CZsynth] Digest Number 139 Hi Jon, Yeah, a stopwatch is pretty imprecise to measure this kind of thing. If a person wanted to try to time somthing, a pitch envelope might work best. [Linearity] The manual text actually spoke of the various rates being angles. I need to look at the manual to find out whether it says anything about the relationship between the levels. I suppose an exponential relationship between levels would be a way to produce an exponential envelope. That would make for some graininess when changing between low levels. The CZs were early digital technologly. I wouldn't be surprised if the envelopes were linear. A book about synthesizer construction (early 90s) mentioned that digital envelopes were, very often, linear. I want to make sure I was right about somthing else: If Rate represent an angle and Level relationships are linear, would I still have been right about the time relationships? If one draws a line between two parallel lines, does a 10 degree angle produce a line twice as long as a 20 degree line? And is this relationship linear? I.e. would the 10 degree line be three times as long as a 30 degree angle? [Possible usefulness of a calculator] Perhaps a calculator would still be useful even if one couldn't find the exact miliseconds involved. If the envelopes are linear, you might be able to synchronize your Amp Pitch and Wave(brightness) envelopes to end their attacks at the same time,etc. <Synchronize your envelopes> Using the [Rate x Time = Distance] equation you could make envelope's "Time" equal. 1. Find the arbitrary "Time" of your first envelope: Devide your first envelope's Distance (between the two levels) by it's Rate. This will give you an arbitrary "Time" value. Distance / Rate = "Time" 2. Use the "Time" from your first envelope to find the Rates for your other envelopes: Next, divide the Distance (Between levels) of your other envelopes by the "Time" of your first envelope to get the appropriate Rates. Distance / "Time" = Rate Thanks for the good discussion. Yours, Nathan On 25 Mar 2002 12:07:14 -0000 CZsynth@yahoogroups.com writes: > ------------------------ Yahoo! Groups Sponsor > > To unsubscribe from this group, send an email to: > CZsynth-unsubscribe@yahoogroups.com > > > ------------------------------------------------------------------------ > > There is 1 message in this issue. > > Topics in this digest: > > 1. RE: Digest Number 137 > From: "Furman, Jon W." <jfurman@...> > > > ________________________________________________________________________ > ________________________________________________________________________ > > Message: 1 > Date: Sun, 24 Mar 2002 13:43:14 -0500 > From: "Furman, Jon W." <jfurman@...> > Subject: RE: Digest Number 137 > > Nathan your thoughts are good in theory but there are a few things > that > complicate this in practice. The first is that at least my ears > aren't > sensitive enough/fingers fast enough to measure the envelope changes > with a > stop watch. Maybe you might be able to get some kind of > approximation but > I'm too deaf and slow to even come close. And the big issue is that > you're > assuming that these rate/level relationships are linear and I'm > pretty sure > that they're not (at least on most synths). That is the time > represented by > a rate of 50 going from level 1 to 100 is not 5 times the time of a > rate of > 10 going from level 1 to 100. To make matters worse level 50 is > probably not > 5 times the volume(or whatever) of level 10. See what I mean? I know > that in > the synth manuals they always draw the envelope diagrams with > straight lines > but I believe that if you were to graph those values in real life > all those > lines would be curves. > > Jon ________________________________________________________________ GET INTERNET ACCESS FROM JUNO! Juno offers FREE or PREMIUM Internet access for less! Join Juno today! For your FREE software, visit: http://dl.www.juno.com/get/web/. <http://dl.www.juno.com/get/web/.> Yahoo! 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RE: [CZsynth] Digest Number 139
2002-03-26 by Furman, Jon W.