Delay / FX / Distortion Alternate Firmware Dev. Page

Now Available Free!

Play this file into CV in: http://www.freshnelly.com/sdsvco/SDS_VCO_DelayDistFX_V1.00.mp3

This new firmware under development is so interesting, I've decided to dedicate a separate page to it!

There will be 16 different modes, selectable with the WAV knob and indicated by the LED's as with the original VCO firmware. There are two groups, non-distortion & distortion FX. SOme of the distortion FX will be based on the "DistPic" project I did for a personal on-stage box a couple of years ago (that is still underway!) and others are brand new because of the more powerful processor in the SDS_VCO.

So on the WAV list are:
-non-distortion FX-
0-LoFi (8 bit) 3-tap fixed delay (3 knobs controls taps)
1-Phase shift CV controlled phase over 1->100mS
2-Freeze Gate controlled 100mS audio capture. By Gate input
3-Karplus Strong - tuned to CVin 1V/oct
4-Doubler/Pitch with variable sample rate but always doubles
5-Tremolo - semi-clock synced for variety
6-Hi-Fi (12 bit) Delay: Size, rate, feedback. CVin can control size so can re-arrange order
7-Compressor/Expander - fattens notes and percussion, voice etc
-distortion FX-
8-10 Bit Bit Crusher down to 1 bit with VCA control (Auto-level, adj. floor)
9-Stutter binary delay + Phaser
10-Cube distortion - extremely high gain
11-Wave folder: adjustable level(phase), delay offset(shift), 8 different types (folds, vector, ring)
12-High Pass distortion-mixes only high pass as distortion, brick wall HPF
13-Sub Follower - makes a (complex) bass line for your synth passage by  PLL locking
14-Phase x N Distortion (up to 8 layers of phasing)
15-FM LFO: Audio in rate shifted by internal LFO controlled by CVin offset

There isn't much of a manual (3 pages) for this firmware alternate, well beyond the above list, as there aren't any "options" (to keep it simple!) to set etc.
There is no MIDI output if you have the expansion as this is basically pure audio, but don't rule it out completely!

Below are samples made during testing..




Here's a few samples of the SDS_VCO Distortion/Delay Firmware during & after development


The much sought after Karplus Strong delay effect has found a home amongst the 16. It started out rather rough, but with a few refinements seems to be improving!
(see below)
SDS_VCO_pitchShifter.mp3 + Phasing

Can you believe there's a pitch shifter in the SDS_VCO!?
I'm not sure feasable this will be to make variable beyond just doubling everything, but it may be possible. I did have it in 5ths at one point.The grain size is variable as is the buffer size.
The second half of the sample is a simple phasing test.

 The Reflex LiveLoop has a stutter effect, but sounds fairly different than this but the method is almost identical. A binary value (from the knob) is laid over the sample address nulling some of it so the quality degrades in a selective way.
It sort of sounds like a speaker getting fried!

I was right, Karplus has improved! Now it would be nice if it would follow a CV input @ 1V/octave.

There is a variable buffer size, but may take that out..


 It won't win any awards for reproduction quality, but it's a nice little delay with near 100% feedback that can be built up at different rates, has a variable buffer size, and will eventually be trigger sync-able.
Keep in mind there's no audio anti-aliasing hardware here. Not bad for 12 bits!

The Freeze Mode is proving to be fun! This is Jean-Paul being twisted by a random gate to freeze vocals. The sample rate offset is lowered to let a CV sequence alter it. The buffer size is also varied sometimes. If this had been more synced it would have been more in time but gives an idea of what can be done with freeze mode.


In getting the Karplus into 1V/Octave CV Input range I recorded this. The RIT_M was simply cycling through a CV sequence offset to match the key I'm in on the piano. I played and sang live as I've never done this before!

At one point I came around to vary the RIT_M's CV as a refrain. Sounds not bad!


Hi-Pass distortion is a digital "brick wall" hi-pass that can have distortion applied to get a raspy & sharp spikey sound. Ramp type waves work well with this mode, but also percussion can be "noise-ified" on the snares and hats than re-mixed back with the original (not inside module) to exaggerate those elements. BTW, mp3 does this great injustice, it sounds so much better live!



I thought that tremolo would be boring but it turned out to be pretty good. The ATK knob sets the tremolo speed then a clock is applied. Locking to the clock is attempted by holding the tremolo's LFO state, so rhythms can happen.


The CV in @ 1V/Octave Karplus Mode modification is complete. This also works with some other modes such as phase and stutter. Any mode the uses DCY knob for rate control. Tuned phase anyone?!

Just before releasing the FW Alternate, I decided to add T/G input control over audio on several modes, but others such as #0 LoFi triple delay use it to restart the playbuffer. The gate length changing will drastically change the delay until it completes the buffer. If you can, pan over to the right channel to remove the original audio.



Re: Alternate Firmware Delay/FX/Distortion:
When I set out to create this firmware alternate, I had ideas to base it on a previous distortion board I use primarily with electric guitar. It is an 8 bit processor with only 20MHz speed (PIC).
The RIT_M's processor is much more powerful and runs at 96MHz so the results have been far beyond my expectations. For the past week I have been scrambling to finish this alternate as I really want fellow SDS_VCO owners & DIY'ers to experience it!

I believe the sample rate is around 21KHz which isn't bad considering the amount of raw processing (no Codec's here!) that is going on with most of these modes. Only WAV#5, 13,14, & 15 are left to do. The tremolo will likely be replaced by some other idea as that's boring and anyone (everyone) with a VCA & LFO can do that until the cows come home already.

March 27th
I have managed to almost double the sample rate. It turns out the ADC's were bottle-necking the flow so once a charge/discharge acquire balance was achieved the true rate jumped to 38 KHz. This is good news but some of the Modes (delay ranges, Hi-Pass, phaser) will need to be adjusted to account for the new higher sample rate! It's sweet sounding though and those synth/percussive highs don't Nyquist the hell out of the chain anymore (well they still can if desired!)

March 30th 2018: Release Day!
After some final changes to the T/G input function on Modes that don't use it I have released the Delay/FX/Dist Firmware as V.1.00 !
The only issue that has come up so far is "sluggishness" of the controls when inputting a lower frequency ramp or triangle wave in pure form. This is because the program is trying to find a "flat" area to do the knob and CV input scan that won't affect the audio quality at such a high sample rate. This will be fixed once I find a nice balance for each mode, but in the meantime if the controls become sluggish, just don't use that mode with spiked waveforms.

Delay/FX/Distortion FW Alternate 3 Page Manual




VCO Owner's Manual

2017 DIY Build Manual   DIY MIDI Sheet

SDS_VCO Calibration Procedure

BareBoard DIY Build Manual

Percussion V.1.00 Guide

PureMIDI Beta Guide


 Audio Firmware Updates
SDS_VCO Firmware Page

NEW! Percussion V.1.00 Firmware
Turn your SDS_VCO into a percussion module!
16 tunable parameter percussion sounds

NEW! PureMIDI beta Firmware
Turn your SDS_VCO into an 8 Channel
T/G & CV & knobs to MIDI Controller!

NEW! Delay/FX/Distortion Firmware
Turn your SDS_VCO into an FX processor!
16 different types of delay/FX/Distortion



Contact: sdsvco@freshnelly.com



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