Constructional Difficulty: Easy
This is our hugely popular version of the classic four stage OTA based phaser. Wonderfully lush and smooth, its similar in sound to the phaser used by Jean Michel Jarre on Oxygene and Equinoxe albums.
The unit includes a useful internal low frequency oscillator with accompanying bicolour LED. The centre frequency of the phase shifter can also be controlled by an external control voltage. Thus allowing envelope generators to be used to sweep the phaser to create filter type effects.
The PCB is laid out to accept four high quality Spectrol pots:
Frequency: this controls the frequency of the two notches created by the phase shift network.
Emphasis: this accentuates the feedback signal within the phaser to create a deeper effect.
Modulation: A simple attenuator to adjust the level of the internal LFO or incoming CV.
LFO rate: adjusts the speed of the LFO.
The internal LFO produces a triangle wave output which is also available from a front panel socket. This allows you to use the internal LFO for other modulation purposes. The LFO signal is automatically routed to the modulation depth pot when no jack is inserted in the CV input. The new issue board allows a choice of inverted or non-inverted waveforms. Thus two Equinoxe units can be used for stereo phase panning.
The unit is designed to work with standard MOTM/Oakley signal levels, although it could be easily converted to be driven from other sources including an electric guitar.
This unit is also made by us, in small format, as the RS400 Phaser for the Analogue Systems' Integrator modular.
Sample Downloads
1. Classic swirling chords similar to that heard on the Jean-Michel Jarre Album 'Equinoxe'. This particular sample was played on a Korg Polysix with standard string patch and ensemble mode on. equ-01.mp3
2. Single sawtooth wave from an Oakley VCO used as the raw input. The phaser is swept upwards manually by the Frequency pot. Emphasis is at 75%. equ-02.mp3
3. Three sawtooth VCOs feeding the phaser. The frequency is being swept on every note by an external EG triggered by the keyboard gate. Emphasis at zero. No other filters are used. equ-03.mp3
4. Three VCOs, one tuned an octave up. Again the phaser is being swept with an EG. This time the attack time is set to a medium amount so you can hear it sweeping upwards. Emphasis set to 100%. equ-04.mp3
5. Slightly filtered pink noise is fed into the phaser. Using the inbuilt LFO to modulate the frequency of the phaser. Emphasis at 100%. A little digital reverb has been added to the final output. equ-05.mp3
A rear view of a completed Oakley Equinoxe fitted with the older style issue 2 printed circuit board. The new issue 3 boards are similar but use a different OTA chip as the CA3080 is now obsolete.
Prices
Equinoxe issue 3 PCB
.................................... 19GBP
Equinoxe pot kit ...............................................
13GBP
Equinoxe pot bracket kit
................................... 4GBP
The Pot Kit contains the correct type and quantity of Spectrol 248 potentiometers to complete 1 module.
The Pot Bracket Kit contains the correct type and quantity of Oakley-Spectrol pot brackets and extra Spectrol nuts required to complete one module.
Click here for full price list and ordering details. All prices include VAT at UK rates. Shipping and postage is additional to these prices.
Downloads
Use 'save as...' button to download and view the files. IE users need to right hand mouse click and then choose 'save as'.
Front Panel database
A Schaeffer front panel can be made for a 1U wide, 5U high panel. The database can be found here Equ.fpd
To read this file you will need a copy of 'Frontplatten designer' from Schaeffer. The program also features on-line ordering, so its now even easier to buy your panels from Scheaffer.
The company are based in Berlin in Germany and will send out panels to anywhere in the world. Delivery to the UK normally takes around ten days. For North American users you can also order your Schaeffer panels from Front Panel Express.
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