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Rare but cool FX: Modulated delay, multitracking via multitapped delay, vibe, Pixellator, vocorder, rando-wah, random LFO

These are rare effects, not widely known, yet closely related to well-known effects.

Analog Man presents the Super Rand-O-Matic

tonefrenzy mp3 sample of Randomatic

Modulated delay

Listen to the vocals in the Rush album Signals. The echoed voice is sometimes delayed more, sometimes less, and correspondingly, the pitch of the echoed signal decreases and increases. It was done so subtly there, you practically have to be on psychedelics to notice it. It's very trippy. But don't try it before a saturated power tube, or intermodulation distortion will break the clarity of the amp tone. The DigiTech 2101 and I presume the next generations, 2112 and then 2120, can do this.


Unlike chorus, there is no pitch shifting. Unlike standard echo, there is no feedback to form another echo. Each echo is as loud as the original signal, and the same pitch. It sounds like several guitarists, in tune with each other, playing at nearly the same time. Brian May achieved this, with clear saturated-amp tone, by taking the signal from one tape-delay head and sending it to cranked amp #2, and sending the signal from yet another tape-delay head to amp #3. This is how he avoided intermodulation distortion. However, you can simply mic a cranked amp, and send it to a multi-tapped delay stage in the DigiTech processor; that will preserve the clarity of the amp tone.

The Zoom 505 multifx mini floor unit has "doubling", which I assume is this, but only with a single delayed [and nonrepeating] signal, not 2 like Brian May. We need tripling, not just doubling.


Vibe is old and well-known, sort of as a rumor: it's "new" as far as becoming widely available with multiple manufacturers, like happened with tremolo -- there is now a renaissance. The UniVibe is a modification of the phaser. In a phaser, each phasing stage is tuned to the same frequency [is that the freq. of moving through the audible cycle?]. In a Vibe, each stage is tuned to a different frequency. I might have this backwards. Maybe the effects books or sites explain it.

Vibe shootout Guitar Player. April 1996. Winner: Prescription Electronics Vibe Unit. Practical winner: cheap, recommended: Voodoo Labs MicroVibe - I demo'd that, it definitely sounded like Hendrix at Woodstock, rather than a phaser.

Also called "rotating Leslie speaker". Here's one of those:

SongWorks Little Lanilei Rotary Wave Speaker

The AX2 modelling amp and other new multifx products have a "rotating speaker" effect, in addition to a phaser.

Date: Sat, 21 Nov 1998 00:15:07 -0800
From: Scott Lehman
Organization: Harmony Central
To: Michael
Subject: Principles of vibe/Leslie?

> What is the relationship of chorus, flanging, phasing, and vibe? Vibe as in Uni-Vibe, sometimes called: vibrato, rotating speaker, Leslie cabinet.

I don't know exactly what the designers put into the rotating speaker/leslie effect, but it's definitely some sort of phasing, maybe with more than one filtered copy of the input to sort of sound like the multiple speakers.

Vibrato can be produced by a variable length delay. When you're decreasing the delay time, it's kind of like playing a tape back at slightly higher speed, and as the delay time increases, the pitch is lowers like when your finger on a cassette wheel to slow it down.

Phasing, flanging, and chorusing are closely related. Let's start with phasing. The idea is to create notches in the frequency response by altering the phase of the input, and then adding it to the original input. You create the phase change with an allpass filter (or more often a chain of 4 or 6 of them.) The allpass filters are changing over time so that the notches move. The flanger is one specific kind of a phaser. We can consider a plain delay to be an allpass filter, and then sweep the delay time. A very short delay produces a whole bunch of notches when you add it to the original input signal, and when we change the delay time, the notches sweep all together. That's how a flanger works. Chorus is essentially the same as the flanger, but the delay times are longer (say 20ms. or so) which is perceived more like a doubling by the ear, like multiple instruments are playing in unison (they don't all strum at precisely the same time.) Also, in a chorus there's usually no feedback applied around the delay element.

I have some detailed articles explaining these effects.

> I am interested in a new type of auto-cycling wah: rando-wah. I am not interested in envelope filtering here, but a variation of auto-wah cycling. I wonder if the Digitech 2120 has a variety of LFO curves too choose from: not just the classic sine, square, triangle, but also, random/unpredictable. As when I put 3 phasers in series, slow, and out of sync, for unpredictable warping.

I actually haven't heard of that, but it sounds cool. I've seen chorus done with a random delay, rather than a typical LFO, which might be a more realistic model of two people playing in unison. The 2120 only has a sine, triangle, and two other waveforms which look kind of like a comb filter and the negative of it. Of course it could probably be mapped to a controller, but I don't think it can do random.

I've been working on an audio processing program for a while to sort of play with stuff like this. It's hardly complete, but with some more building blocks, it could do some interesting stuff. If you have some ideas on cool effects, I'd like to hear them and maybe try to implement some of it.

> Please take a look at my site.
> http://www.amptone.com -- Amp Tone and Effects Placement. Covers low-power

I know we have the site listed. Lots of great stuff! I know some people in the Forum loved it.

| Scott Lehman slehman at harmony-central.com |
| Harmony Central Musicians Resource - http://www.harmony-central.com/ |
| "We didn't want a victory, we just wanted to fight" - New Model Army |


Designed by Nine Inch Nails (a Goth/Industrial band) and DigiTech.

DOD floor processors with Pixellator

Sounds like direct guitar reproduced by a horribly lo-fi, 4-bit sound card, then run through distortion.

Co-designed by Charlie Clouser of Nine Inch Nails.

This is an effect developed by NIN and DigiTech together. It is a form of undersampling. It sounds like a crappy 8-bit soundcard, or 4-bit soundcard, with an irritating digital whine or thin buzz or whistle behind the sound. Really sounds awful, in a digital lo-tech way, before distortion. Sounds very similar to ring modulator. Heard in a DOD floor multifx unit. Look for "Pixellator" in the effects charts on the DOD floor units. TEC 4 - This model features 15 analog distortions, 15 effects like the pixellator, ring modulator, chorus, reverbs, delays, flange, EQ and more while using up to 7 of these effects at once......30 user programs, 30 factory programs, built-in chromatic tuner, headphone jack, etc. $169.95 list. Our normal price $136. Our special price $115.00. - http://www.pulseonline.com/dodrt.htm

G10 Rackmount Guitar Effects Midi controllable ultimate effect unit with all of DOD's great effects built-in....like the great pixellator and ring modulator effects. Use up to 7 outrageous effects at one time. Huge easy to read LCD display. Chromatic tuner. list $299.95 Pulse's Price.......$239.99

VOFX A first for vocalists. Apply your vocal effects in real time (as compared to artificial time?)....Plug your mic into the XLR input, then choose to add from one to 7 simultaneous delay, reverb, chorus, flange, phase shifting, tremolo, EQ noise gating or compression effects.....and even DOD's Pixellator, Ring Modulation and Mic Drive. 30 user and 30 factory programs offer the best in storage ability. list $299.95 Pulse Price.......$254.49

official VoTec info

DOD TEC4 BassTec - DOD has also recently released two new full-featured, multi-effects floor pedals. First is the TEC4 BassTec ($189.95), a bass guitar preamp/processor pedal board featuring 30 factory presets including a Noise Gate, three band EQ, Auto Swell, Pitch Shifter, Ring Modulator, Reverb and Multi-Tap Delay. One really cool new effect is the "pixellator," which is a digital undersampler designed to degrade the signal (this should be popular for all of you working in industrial, techno and rap). Another unique feature is something called "psychobass," which puts an amplitude envelope on phasers and flangers to create a bass-synthesizer type effect. The Tec4 also offers 30 user-definable presets for making and storing your own custom effects. --Edward Tywoniak

DOD TEC8G - And finally, from the same TEC family of processors, comes the TEC8G ($299.95) floor-controlled multi-effects processor. The TEC8G is a follow-up product to the TEC8 with the difference being the addition of a "grunge" circuit that emulates the sound of your favorite cabinets. The TEC8G includes an Expression Controller pedal with a slightly right-angled skew designed to be more ergonomically playable. The unit also includes a "jam-along-jack" that allows you to play along with a CD or cassette. The TEC8G comes with a full compliment of sound effects including some interesting ones like Analog Wah, Pixellator, and Grind Distortion. DOD, 8760 Sandy Parkway, Sandy, Utah 84070; Tel: 801-566-8800, Fax:801-566-7005 -- Edward Tywoniak


Using the voice to modulate an instrument sound. Uses EQ filtering, I think.

DOD VoFX stereo vocal fx pedal. $300 VoTEC, similar, $200. "VoFX: A first for vocalists. Plug your mic into the XLR input, then choose to add from one to 7 simultaneous delay, reverb, chorus, flange, phase shifting, tremolo, EQ noise gating or compression effects.....and even DOD's Pixellator, Ring Modulation and Mic Drive. 30 user and 30 factory programs offer the best in storage ability. list $299.95 Pulse Price.......$254.49 -- http://www.pulseonline.com/dodrt.htm

Digitech Talker. Voice/instrument interface. Vocorder effects and talkbox effects. $230. Guitar Player July 1998.
support at digitech.com Digitech.

Several Vocorder links

Amptone.com ultra gear-search page

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