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Projects => Build Reports => Topic started by: Aleph Null on May 23, 2023, 05:11:17 PM

Title: Special Sauce — Chorus, Vibrato, Doubler, Slap-Back Delay (with Demo)
Post by: Aleph Null on May 23, 2023, 05:11:17 PM
Special Sauce is for when your tone needs a little something extra. It's a PT2399 based delay with envelope controlled pitch modulation that does chorus, vibrato, doubling, or slap-back delay.

(https://live.staticflickr.com/65535/52920423293_6df0b75bfa_c.jpg) (https://flic.kr/p/2oCp18g)

The board is mounted to a wooden standoff with hot glue. It sounds precarious, but it's the best way I've found to mount vero builds.

(https://live.staticflickr.com/65535/52919964876_3f51c29800_c.jpg) (https://flic.kr/p/2oCmDRw)

This circuit is tuned for short, bright delays ranging from 30–150ms or so. The short delay time meant I could use the first CMOS stage of the PT2399 as an input buffer instead of for filtering. A Mosfet at the output supplies 0—35dB of gain. The real trick here is using the voltage on pin 8 as an envelope follower (as discovered by DeadAstronaut). Instead of applying the pin 8 voltage directly to pin 6, I used it to control a 2N5089 set up as a voltage sink. This makes the pitch bending much more pronounced, especially at shorter delay times.

(https://live.staticflickr.com/65535/52919964031_c3ce80aaaa_c.jpg) (https://flic.kr/p/2oCmDAX)

Here's  a short demo:



Here's my layout, if anyone else wants to build it.

(https://live.staticflickr.com/65535/52920124164_6021895cdd_c.jpg) (https://flic.kr/p/2oCntcS)
Title: Re: Special Sauce — Chorus, Vibrato, Doubler, Slap-Back Delay (with Demo)
Post by: jimilee on May 23, 2023, 06:03:29 PM
Man, that's really cool. Nicely done.
Title: Re: Special Sauce — Chorus, Vibrato, Doubler, Slap-Back Delay (with Demo)
Post by: zombie_rock123 on May 23, 2023, 10:23:45 PM
Awesome design! The doubling is super sweet. Love that the range is useful on everything, I never manage that  ;D
Title: Re: Special Sauce — Chorus, Vibrato, Doubler, Slap-Back Delay (with Demo)
Post by: Aleph Null on May 24, 2023, 03:16:13 PM
Quote from: zombie_rock123 on May 23, 2023, 10:23:45 PM
Awesome design! The doubling is super sweet. Love that the range is useful on everything, I never manage that  ;D

Thanks! It was definitely hard to resist the temptation to add more range to the "Detune" control, but if I want octave drops on sixteenth-note repeats, I'll get my Clari(not) out.
Title: Re: Special Sauce — Chorus, Vibrato, Doubler, Slap-Back Delay (with Demo)
Post by: gordo on May 24, 2023, 11:54:26 PM
And what a cool demo!!
Title: Re: Special Sauce — Chorus, Vibrato, Doubler, Slap-Back Delay (with Demo)
Post by: jessenator on May 25, 2023, 12:43:49 AM
Really slick work! I dig that doubling effect also.
Title: Re: Special Sauce — Chorus, Vibrato, Doubler, Slap-Back Delay (with Demo)
Post by: Aleph Null on May 25, 2023, 09:05:05 PM
Quote from: gordo on May 24, 2023, 11:54:26 PM
And what a cool demo!!

Thanks! I didn't want to futz with video editing software, so I had to find a way to do it in one take without any fancy title cards or captions. I also didn't want to yammer into the camera. My favorite demos have always been of the "less talking, more rocking" variety.
Title: Re: Special Sauce — Chorus, Vibrato, Doubler, Slap-Back Delay (with Demo)
Post by: Boba7 on May 28, 2023, 12:37:28 PM
Wow that's really cool, and there are so many sounds with such a simple (dare I say elegant!) design!
I'd love to hear more vibrato (full wet, minimum delay) samples with various depth settings!
Amazing job, thanks for sharing!
Title: Re: Special Sauce — Chorus, Vibrato, Doubler, Slap-Back Delay (with Demo)
Post by: LaceSensor on May 30, 2023, 08:40:34 PM
so, this is sick, hey
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