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Rev2 Karplus

Rev2 Karplus
« on: March 12, 2019, 10:40:55 AM »
Hey guys, Someone recently turned me onto the fact the Rev2 would be a worthy source of some Karplus Stong type synthesized sounds. Here is a demo of some fooling around with the idea.

In short, Karplus Stong synthesis uses a tuned short delay for sound generation. You have to feed a tiny blip of sound into the delay first just to trigger it.

It takes a fair amount of fine tuning and experimentation to get things that sound good but here is a quick write up of how to get to the starting point for these kinds of sounds.

-Turn OSC off and noise all the way up.
-Set amp sustain to 0 and decay like 3
-Turn on the mono or stereo delay with the time at 0 and feedback at 100
-Create a keynote modulation for the delay time with an amount of about 5

Of course this is just a starting point to be fine tuned. All of the parameters I listed in bold are prime targets for manipulation and fine tuning of this sound. Fun stuff! Enjoy

https://clyp.it/btfscizp (sound demo for those not logged in)


« Last Edit: March 12, 2019, 10:55:55 AM by philroyjenkins »

Re: Rev2 Karplus
« Reply #1 on: March 12, 2019, 11:59:03 AM »
Interesting concept.
Don't you think you somehow turned the analog synth into something totally digitallish  ;D

Re: Rev2 Karplus
« Reply #2 on: March 12, 2019, 12:54:22 PM »
Interesting concept.
Don't you think you somehow turned the analog synth into something totally digitallish  ;D

Heh, you kid but TBH some of my favorite sounds on the Rev2 lean towards the digital side of things.

https://clyp.it/klhu4x50 - https://clyp.it/4imonf3c

I try not to care about things like analog and digital and just focus on discovering sounds and areas of exploration that are usable to me (even if sometimes in a noisy/chaotic way.)

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Re: Rev2 Karplus
« Reply #3 on: March 12, 2019, 01:11:35 PM »
Thatís what Iím talkiní bout...more nasty sounds out of the REV2! 
DSI Prophet Rev2-8, Moog Subsequent 37, Roland Alpha Juno 2, Korg Minilogue XD, Novation Bass Station 2, Korg Poly 800, Roland JX 03, BOSS VE500, MOTU Micro Lite, Antelope Audio Zen Tour, iMac 2016, Logic X
www.syzygyxmusic.com
https://syzygy-x.bandcamp.com

Re: Rev2 Karplus
« Reply #4 on: March 12, 2019, 03:43:24 PM »
Thatís what Iím talkiní bout...more nasty sounds out of the REV2!

Ayy, one more just for you!

https://clyp.it/ucw44wdm - foolin around with one of my go to aggressive patches. A bit exaggerated here but I really just wanted to show this specific kind of snarl the rev2 could pull off. Tamed down a bit and it makes a great burnt 808.

Who says digital distortion can't be useful? I love the rev2 distortion on a self osc filter, especially when you involve audio out as mod source on that same cutoff to help make things a bit more organic and interactive to your playing.
« Last Edit: March 12, 2019, 03:47:09 PM by philroyjenkins »

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Re: Rev2 Karplus
« Reply #5 on: March 12, 2019, 06:00:25 PM »
Hell yah Philroy that Pat h is fuckiní sick!  I love hearing hard edged sounds from the REV2 cause itís rare that Iím hearing them in any demos people make, itís usually softer ambient style patches which are great and all but the board is so capable of nasty sounds too, which is why I love the REV2, such a vast style of sounds
DSI Prophet Rev2-8, Moog Subsequent 37, Roland Alpha Juno 2, Korg Minilogue XD, Novation Bass Station 2, Korg Poly 800, Roland JX 03, BOSS VE500, MOTU Micro Lite, Antelope Audio Zen Tour, iMac 2016, Logic X
www.syzygyxmusic.com
https://syzygy-x.bandcamp.com

Re: Rev2 Karplus
« Reply #6 on: March 13, 2019, 08:02:10 AM »
I try not to care about things like analog and digital and just focus on discovering sounds and areas of exploration that are usable to me (even if sometimes in a noisy/chaotic way.)

I like this attitude-- let your ears be your guide!  Although the Karplus-Strong algorithm is inherently digital, it was approximating something that was previously done with analog filters & delays.  Your creation seems less like an approximation of K-S than an expansion on the forms that K-S was originally mimicking.

Back in the mid 80s when K-S was devised, it was special because good digital filters couldn't be done in real-time with cheap general-purpose CPUs.  In its simplest form, K-S is computationally inexpensive: All you do is take the average of two consecutive samples and feed them back into the delay line. It produces a decaying tone whose period is set by the length of the delay.

The first implementation of K-S I saw was in 1988 or 1989 on a NeXT computer!

I love hearing hard edged sounds from the REV2 cause itís rare that Iím hearing them in any demos people make, itís usually softer ambient style patches which are great and all but the board is so capable of nasty sounds too, which is why I love the REV2, such a vast style of sounds

When I first got my Rev2 a few months ago and cycled through the presets, it seemed there were a lot of hard-edged patches.  It's just that they aren't hard-edged in a way that's particularly musically-useful or suited to combination with other sounds.  That may be why people making demos focus on the ambient ones.

Re: Rev2 Karplus
« Reply #7 on: March 13, 2019, 08:10:38 AM »
Nicely done, philroyjenkins! I love hearing the REV2 do unexpected things. I've gotten some similar sounds while using a Max for Live device I designed to degrade parameters over time. The timbral possibilities in this machine probably exceed the number atoms in the universe, or at least the number of atoms in a medium sized piece of fruit. :-P

Re: Rev2 Karplus
« Reply #8 on: March 13, 2019, 08:24:51 AM »
Love that "Burnt" one.  Sounds like playing an instrument made of radio tower guy-wires. 

Re: Rev2 Karplus
« Reply #9 on: March 13, 2019, 09:24:57 AM »
I try not to care about things like analog and digital and just focus on discovering sounds and areas of exploration that are usable to me (even if sometimes in a noisy/chaotic way.)

I like this attitude-- let your ears be your guide!  Although the Karplus-Strong algorithm is inherently digital, it was approximating something that was previously done with analog filters & delays.  Your creation seems less like an approximation of K-S than an expansion on the forms that K-S was originally mimicking.

Back in the mid 80s when K-S was devised, it was special because good digital filters couldn't be done in real-time with cheap general-purpose CPUs.  In its simplest form, K-S is computationally inexpensive: All you do is take the average of two consecutive samples and feed them back into the delay line. It produces a decaying tone whose period is set by the length of the delay.

The first implementation of K-S I saw was in 1988 or 1989 on a NeXT computer!

Very cool stuff! I appreciate this bit of history. I deal a bit with max4live and this makes me think it would be pretty trivial to whip up a K-S device.

Nicely done, philroyjenkins! I love hearing the REV2 do unexpected things. I've gotten some similar sounds while using a Max for Live device I designed to degrade parameters over time. The timbral possibilities in this machine probably exceed the number atoms in the universe, or at least the number of atoms in a medium sized piece of fruit. :-P

Thanks bud. I've been meaning to check that device out from ya!

I'm working on an arduino midi patch changer for the Rev2 with a simple 9 digit keypad to enter the patch numbers instead of using the program knob. To be honest I really only need one bank of patches and I prefer remember a numbering system to a naming one. 1-9 will be my favorites, 10-19 basses, 20-29 pads etc etc.

Anyways, I plan on adding in a special code entry to the keypad that will completely randomize every midi cc. Thought you'd appreciate that bit.

Love that "Burnt" one.  Sounds like playing an instrument made of radio tower guy-wires. 

Thanks man! That wiggle in pitch is thanks to the audio out mod source. Its become one of my favorite ways to add a bit of organic interactivity to an otherwise static patch.

I've been following your efforts to better approximate VCO behavior on the Rev2 and I just think its frickin awesome that this synth has this much potential for such varied experimentation on seemingly opposite ends of the sonic spectrum.


Re: Rev2 Karplus
« Reply #10 on: March 13, 2019, 10:57:42 AM »
Very cool stuff! I appreciate this bit of history. I deal a bit with max4live and this makes me think it would be pretty trivial to whip up a K-S device.
If you want the full description, I found Karplus & Strong's original 1983 article is free online: https://www.jstor.org/stable/3680062

Re: Rev2 Karplus
« Reply #11 on: March 13, 2019, 11:08:49 PM »
Thanks, yet another sonic landscape to explore. This is a lot of fun!
DSI Prophet Rev2 16 voice, Arturia Drumbrute Impact, Tascam DP-008 EX

Re: Rev2 Karplus
« Reply #12 on: March 16, 2019, 01:54:56 PM »
Nice. Karplus was one of the fun things about the (Poly)Evolver and its availability on the Rev2 was one of the things to convince me convert.

Re: Rev2 Karplus
« Reply #13 on: March 24, 2019, 09:42:16 AM »
Nice!

Though some basic / more traditional functions still lack a little bit on the REV2 for playing a polysynth live (things like more than 4V chord memory and also the lack of a HOLD RELATCH option, please DSI, not on ARP only!), I really enjoy this synth more and more because of it's great balance between sound quality and flexibility.

This Karplus-related idea is nice and shows that the REV2 is capable for some weird sound design also, making you turning knobs and being surprised and inspired each time you use the synth...

I always find myself starting from an INIT patch, ending up with at least 5 very different 'versions' of that sound! :-)

I use a Strymon DECO or other tape / tube FX or FX plugin to give the REV's sound some more warmth and 'analog' vibe and to tame the bright filter / oscillators a little. Together with some additional HW or plugin FX, possibilities are endless...


With this karplus method I accidentally created a nice evolving beat / percussion loop. One minute later I was creating some very weird  sounds that might be useful for a project later this year or just to get some special FX samples from...

Again, possibilities are almost endless with this beast.

Thanks for sharing this great tip!





Re: Rev2 Karplus
« Reply #14 on: March 25, 2019, 08:38:35 AM »
Nice!
This Karplus-related idea is nice and shows that the REV2 is capable for some weird sound design also, making you turning knobs and being surprised and inspired each time you use the synth...

Exactly man. I first got into synths because I really liked that meditative place you reach of becoming one with the sound. Tweaking it in real time and being totally surprised at times while still maintaining control over the general shaping going on.

There was an awesome quote I've heard attributed to Brian Eno (but who really knows) that goes something like "Synthesizers replace the need for skill with the need for judgement."

I've always loved this idea. Its kind of like the synth is doing its own thing and we are merely setting the boundaries in which it can operate.

Re: Rev2 Karplus
« Reply #15 on: March 25, 2019, 08:43:37 AM »
Nice. Karplus was one of the fun things about the (Poly)Evolver and its availability on the Rev2 was one of the things to convince me convert.

Oh man, I'd love to spend some time with a Poly Evolver one day.

Re: Rev2 Karplus
« Reply #16 on: March 25, 2019, 03:21:26 PM »
One of my favorite quotes: 
"Creativity is allowing yourself to make mistakes, art is knowing which ones to keep" - Scott Adams?

Nice!
This Karplus-related idea is nice and shows that the REV2 is capable for some weird sound design also, making you turning knobs and being surprised and inspired each time you use the synth...

Exactly man. I first got into synths because I really liked that meditative place you reach of becoming one with the sound. Tweaking it in real time and being totally surprised at times while still maintaining control over the general shaping going on.

There was an awesome quote I've heard attributed to Brian Eno (but who really knows) that goes something like "Synthesizers replace the need for skill with the need for judgement."

I've always loved this idea. Its kind of like the synth is doing its own thing and we are merely setting the boundaries in which it can operate.