New Rapture Tutorial Available

The Filter Modulators Page

http://www.catherinefasci...ed/RF/Rapture%Cut1.jpg

doesn't work , either wrong link or image missing.. i'm guesing it's the % causing tyhe issue in the filename.

funny enough I got the synths book today as well.. seems I have a lot of reading to do.

no worries, it's fine now.. reading simons book at the moment.. well some of he chapters, since I don't have the sampler.

chad


Hi David,

Thanks for sharing! 

My first comments so far:

"Although this is getting a bit ahead of the discussion, it’s a good time to mention that we can get slopes of greater that 36 dB-per-octave by placing two filters in series."

It's also possible to get very high resonant filters by increasing the resonance depth within the modulation matrix for a single filter. (using the CC127 mod matrix trick) 

-  Open mod matrix
-  Assign source as CC127
-  Assign the destination as your Filter Resonance
-  Set Depth to +40 (you now have an instant +40 dB on your filter)
-  Repeat the assignments as necessary on the same filter for uber-self-resonanting style filters, just don't forget to enable a limiter somewhere in your output.  =)

I guess this means that a later statement that resonance value is bound between 0 and 40 is in error.  I confess I focused mostly on cutoff modulation and gave resonance modulation only a cursory treatment.  I'll revisit this and possibly revise the tutorial when I get a chance.  Thanks.

Ya I was trying to suggest that the Mod Matrix can be used in a way to expand parameter caps within each element.  Using resonance is just one example. 

For fun you should try negative depths on a 'Volume LFO Depth'. 

Open your matrix and enter the following modulations:
-  CC127 | Volume LFO Depth 1 | - 6.0dB
-  CC127 | Volume LFO Depth 1 | - 6.0dB (twice for good measure)

-  Now load up a funky shaped LFO in the AMP LFO and set your sync to 1/8ths or 1/4s. 

b rock

I guess this means that a later statement that resonance value is bound between 0 and 40 is in error.

It isn't an error, David.  You cited the range of a Resonance control under default conditions.  I believe that Chad was simply pointing out another cool feature to exploit.
 
CC127 -> Resonance slots in the Matrix can add up to 40 dB more Depth per slot.  You can keep adding multiple slots with identical values ... Eventually, you'll get to a parameter value 'cap' that Rene has programmed in to protect us from ourselves.   Another variation on this particular theme is to use the KeyTrack widget as a 'master' control over a Modulator.
 
Click on the KeyTrack widget for 'focus', then use the Page Up / Page Down or Up / Down arrow keys on the Qwerty to adjust the base value range.  That type of action moves both KeyTrack nodes up & down simultaneously.  It will work with any Modulator's KeyTrack control.  I like to use the widget in the Amplitude Modulator as an Element's master volume control.

I've done some further experimentation and the results I get (that is, what I hear), is that the internal cap is 40, period.
 
Try the following:
1. In an empty program, select a waveform (I used several with the same results), select a DSP config., select 2LP for the filter type, set the cutoff to something that accentuates the resonance setting throught the dial range.  Set the resonance setting to max.
2. Copy and paste E1 to E2, and set the E2 resonance to half (20dB).
3. Provide a mod. matrix entry where CC1 is mapped to E2 F1 resonance.  Set the depth to 40.
4. Play with E2 solo-ed.  For me, I hear sound changes in the lower half of the mod. wheel position.  But after the halfway point, the sound doesn't change.
5. Compare E1 with E2.  To me they sound identical for any mod wheel position at or above the halfway point.
 
So, I can't help but conclude that you can't nudge the resonance value above 40 ... that is, internal truncation to 40 is done after any mod matrix assists.  Anyway, that's my story and I'm sticking to it. 

chad

If you left your Cutoff Freq for the 2LP filter static you may not be able to hear a difference for that particular test.  But if you move or modulate the Cutoff knob for that filter with 80 dB of resonance vs 40 you'll definitely be able to hear the difference.  You can do this with a single element, to keep things easier.  And anything past 80 dB the self oscillating becomes very apparent when changing the cutoff freq.  Easy to see within a spectrum analyzer as well.

Although now you've peaked my interest of what the 'cap' really is. 
 

OK, your method does indeed produce some extreme behavior.  I'm going to speculate that there is checking and truncation to the max value of 40 in some places, but whether intentionally or otherwise, it's inconsistent.  Specifically, if you force an extreme resonance value with the mod. matrix and twirl the cutoff dial, you get over-the-top sounds while holding the key down, just as you promised would happen.  But if you let the key up and depress it again, it seems to revert to a sound that produced with the resonance value trimmed back to 40.
 
Perhaps we can agree this behavior is a "feature".  I'm not going to agonize over figuring it out, as the effect isn't one I'd be interested in applying to music (assuming I ever get around to actually creating some music, rather than playing around with the synth to discover all of its potential).