Question about Leslie speaker simulation DSP

[SciNote]

When I check the manual of these new CTS keyboards, I see how the DSP effects can be customized.  With the Leslie speaker simulation, I see that one of the parameters you can adjust is the acceleration/rate-of-change of the speeding up or slowing down of the Leslie speaker effect.  My questions is, when and how would this be used?  There is no button on the keyboard to change the Leslie/rotary speaker speed, so when would a Leslie speed-up/slow-down effect come in to play?

 

I'll add that I have an old CTK-691 from about 2003 that has this same feature, and I never knew how it would be used on that keyboard, either.  I assumed that it might be something that would be used if the keyboard was being controlled through MIDI, but I never looked into it.

Edited February 4, 2022 by SciNote

[Brad Saucier]

I suggest searching for videos on organ playing techniques, specifically those using the rotary speaker setup.  The speed is manipulated live for a musical effect during a performance.  You can assign this speed change effect to a knob on CT-S500 or 1000V, assuming that's the models you're asking about.

[SciNote]

I learned how to play keyboard on organ, so I am familiar with the operation of a rotary speaker and how it is used during a performance.  My question is related to exactly how this speed-up and slow-down effect is applied to the sound.

 

Now, I've been looking at the manual, and I see the parameter details of the rotary speaker effects on pages EN-293 and EN-294 (for rotary and drive-rotary) in the CTS-500 manual.  Maybe I just did not see this clearly stated in the manual, but I'm now thinking that you can assign any of these listed parameters to the knobs to adjust during a performance while Active DSP is switched on and set to a DSP mode that includes a rotary speaker module.  So, for the rotary effect, the parameters listed are rotary speaker type, rotary speed (fast/slow), rotary speaker stop, rise acceleration, fall acceleration, slow rate, fast rate, vibrato/chorus, wet level, and dry level.

 

So, if you can set any of the above listed parameters to the knobs, then I'm curious about the rotary speed (fast/slow) parameter.  If this is assigned to a knob, does rotating this knob simply toggle between slow and fast modes?  In other words, does this mode simply treat the knob as a two-position switch, where rotating the knob to one part of its sweep is "slow", and the other part of its sweep is "fast"?

 

If so, then that is a good feature, and then I can see how the rise and fall acceleration effects would come into play.  I originally thought that you could only change the speed of the rotary speaker just by directly setting the speed with a knob, where the continuously variable sweep of the knob would directly correspond to the rotary speed, and that the rate of change of the rotary speed would just be dependent on how fast you turn the knob.  In that case, your left hand would be occupied adjusting the knob to get the speed-up and slow-down effects characteristic of a real Leslie speaker.  But if you can simply "snap" the knob left or right while playing to instantly switch between fast and slow modes, while letting the keyboard handle the rotary speed ramp-up and slow-down after you "snap" the knob to the desired speed, then you can much more easily play the keyboard like a real organist, and just quickly use your left hand to select speed modes, and then go back to using your left hand for playing the keyboard while the keyboard ramps up or slows down the rotary speed.  I'll really have to get my hands on one of these keyboards to test this out.

 

Of course, even if this is the case, this does not explain how these parameter settings work in my old CTK-691, as this keyboard does not have any kind of live-control knobs or buttons to change the parameters while playing, but that is a discussion for another day and another part of the forum.

Edited February 5, 2022 by SciNote

[Brad Saucier]

7 hours ago, SciNote said:

If this is assigned to a knob, does rotating this knob simply toggle between slow and fast modes? 

 

I misunderstood your original question, apologies.   Yes, that's exactly how it works.  The knob acts like an on/off button.  The target rate for each end of the speed spectrum can be configured by adjusting "slow rate" and "fast rate".  

[pjd]

Hi Bob --

 

Fancy meeting you here? 😀

 

Works as Brad described it. I just set this up on CT-S1000V. I didn't like the default acceleration or fast rate in the Amp Organ 1 voice and changed it. BTW, the rotary sim includes chorus/vibrato. (Nice.)

 

Active DSP assigns DSP parameters to the knobs. If Active DSP HOLD is enabled, the knobs will retain the assignment after leaving the Active DSP screen. Everything can be and is saved to a registration and/or a MY SETUP location including the new parameter values.

 

When rotary speed is assigned to a knob, the speed changes somewhere in the middle. So it isn't necessary to spin the dial from full left to full right, or vice versa. Of course, it would be great to have rotary speed assigned to the foot pedal. (Maybe in an update?) Knob 3 has BRAKE to stop spin. (Nice.) 

 

I've got a new post on my site about this: http://sandsoftwaresound.net/casio-ct-s1000v-quick-tips/

 

All the best -- pj

 

[c0l0rad0an]

My CT-S500 arrives in a few days, and I plan to try using PEDAL 1 to step thru the 4 slots of a registration bank, wrapping from 4 to 1.  I'll dedicate all 4 slots to an organ patch. Slots 1 and 3 will have rotary speed SLOW; slots 2 and 4 will be FAST. If this all works, each pedal press will toggle the speed of the rotary.

"Think it'll work?

 It would take a miracle!"

[c0l0rad0an]

A couple discoveries about the CT-S500:

 - The PEDAL 1 jack does not seem to sense pedal polarity. (What non-sense is this?  )

 - Using PEDAL 1 to sequence thru Registrations changes the Bank number when stepping directly between slot 4 and slot 1. That makes sense, and might be obvious to most people, but my reading of the manual led me to think that the Bank number would remain fixed.

 

Unproven and perhaps misguided thoughts about Leslie speed control (besides using a Knob):

 - Layer a slow-speed organ patch with a fast-speed organ patch and crossfade between them via MIDI. It won't give the acceleration/deceleration, though.

 - Use VIBRATO Rate as a poor substitute, and control it with MIDI.

 - Use the servo motor from an Arduino kit and mechanically link it to "the Knob". For extra credit, fashion a miniature human hand as part of the linkage. Control the servo with a processor, or a simple 555 circuit inside a footswitch body. Crazy, I know; but notice how similar "Lester" and "Fester" are...

(Feel free to attempt the use of reason and logic (not the DAWs) to dislodge these musings.  )

[Tbone55]

This topic answered some of the questions I had about the Leslie rotary effect. I just got my px-S3000 about 2 weeks ago and have been working my way through some of the features I'm likely to use.

 

I still need to play around with the accel and decel rates as right now I don't feel it's quite right. I'll add that I am used to playing an organ through a Leslie cabinet using a Leslie pre amp pedal so I do have experience with this effect. 

 

So if knob 1 controls turning the Leslie effect on and off what, if any, function does knob 2 control? Curious minds would like to know 😁.

 

 

[Brad Saucier]

On the PX-S3000, "knob sets" are predefined.  For the rotary effect, "DSP Parameter" is the knob set being used.  Knob 1 and 2 are targeting two of the most likely used parameters you'll find under that particular DSP effect.