DIY SynthesizersInterfaces and sub-systemsDIY Audio Efects
Go to the HomepageWhat's up Doc ?Go to the Linkpagem.bareille

WARP633 - Ring Modulator




The Warp633 is a Ring Modulator /Warper based on the 4 quadrant multiplier chip AD633 made by Analog Devices.
This module is inspired by Roman Sowa's Ring Modulator schematic upgraded with a "Divide / Multiply " mode selector. The Multiply mode provide all classic RingMod sounds and applications :freq doubling, VCA, etc... The "Divide" mode is a true waveshaper of the outer space. It is "Easy Clipping "

A "Z" input is also available to add offsets for advanced clipped sounds ...X and Y inputs are fitted with attenuators. There is a MIX pot (dry/wet) between the Y direct and the processed signal. It allow bypassing the ring modulator a very smooth way and it work in all modes.


The WARP633 module compute the following simplified equations according to the mode switch position.


Out = (X.Y).m+Z

Out = (Y/X).m+Z

X,Y = signal inputs carrier and modulation ( ac/dc ,10Vpp)
m = gain factor - require one extra potentiometer (option)
Z = input to add extern modulation/offset to the output (option)

Prototype picture - Clic to enlarge


The Multiply mode is the basic wiring of the AD633 for asymetrical signals. The divide mode is made by wiring the AD633 into the feedback loop of an opamp (U2A)

Note that many parts are optional and can be forgotten if you want to build a low cost version ...

  1. RV3/RV4 and their associated resistors can be removed if you do not care that much about offsets ...In this case , inputs X2 ,Y2 must be grounded.
  2. Same thing with the AC/DC switches on X,Y inputs ...
  3. The Z input must be grouded if unused.
  4. J100/R16 are to implement a "gain factor" potentiometer and for experimental purposes ( filters LP/HP etc..check AD633 datasheet).

Other thing ... The schematic shows NE5532 opamps , it is a generic symbol , and the Warp633 will work fine with a lot of dual op-amps. I advise good ones for this module, the AD633 worth them ...The prototype is fitted with a pair of OP275 ( Analog Devices )

Pcb & Smd adapter ...

It is a small module, very simple to build, only few parts are required. Indeed i advise you to use good quality op-amps and to put a socket for the AD633 ... Power supply can be +/-12V or +/-15V.


The pcb is single side with Spectrol pots footprints ( 3 pots /short size ). It is designed for the AD633 in DIP8 format , but as the AD633 in DIP8 package can be hard to find in the future, i have drawned a small adapter to use the SOIC with a classic DIP8 socket. Here is this adapter layout and how to solder the AD633 on it ... It is only valid for the AD633, do not use it to convert other SMD chips to DIP8 ...

The real adapter look like this when finished ...

Front panel

Here are suggested front panels designs in 5U format, 3 or 4 pots versions :


And the sound ?

Here are sound clips using the Warp633 combined with other modules. Provided by Raphaël from Paris.

  1. Warp633 + Buchla291 clone loop ( mp3)
  2. Warp633 Guru (mp3)
  3. Warp633 + Polivoks vcf clone - Loop1 (mp3)
  4. Warp633 + Polivoks vcf clone - Loop3 (mp3)
  5. PaisleyWarp Loop ( mp3)
  6. GroDivide (mp3)

Following files are made with an electric guitar and the MiniWarp633. The guitar is first passed through a Direct Input ( DI) preamp, to get a transparent line level... The DI-preamp do not overload/clip the sound in any way. The preamp output go to the Warp633 'Y' input.A VCO/LFO is connected on the 'X' input .Sine, triangle or pwm waveforms are used at various frequencies. The sound is directly recorded at the Warp633's output.

All the clipped /distorded /detuned sounds are coming from the Warp633 module. Samples have just been normarlised when necessary ...Please be aware that i am not really a guitar player so i did what i could...

warp633guitar1.mp3 Clean slow tremolo (sine)
warp633guitar2.mp3 Clean rapid tremolo
warp633guitar3.mp3 HF mod ring mod
warp633guitar4.mp3 Hard detune ring mod
warp633guitar5.mp3 Searching the tune ... Hard ring mod (tri)
warp633guitar6.mp3 Soft div mode - BF mod + overclip( tm ;)
warp633guitar7.mp3 Div mode - distortion box style ....
warp633guitar8.mp3 Ring mod + pwm + guitar ....S&h style
warp633guitar9.mp3 Div mode distortion , another one...
warp633guitar10.mp3 div mode fuzz style + cut mod...



Warp633 pcb + Construction manual
is available on order

Marc Bareille © 2004-2007