Found a mystery Phasor PCB (RE-90 etched on pcb)?

Started by Simon Owen, January 21, 2006, 04:28:27 PM

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Simon Owen

Hi, Ive found a mystery phasor pcb at the bottom of my junk pile.
It has RE-90 etched on the pcb?
4 dual opamps.
4 K66056 fets
1 2n3819
Sockets are mounted at one end.
The circiut seems to be a variation on the mxr phase 90 with the same type of oscillator as on a mutron phasor II ( two op-amp).
It isn't phasing at the moment, just get a straight signal.

Any clues on who made it?

Dan N

Google says Aria had a RE-90 phaser.

But that would be too easy...

Simon Owen

It helps if I search for phaser not phasor.
Any one have this schematic?
It might be the same as a vox super phaser or a univox phase.

Ta

Simon Owen

Finally got it working, sounds great.
The 4.7v zener had gone open circuit.
Sounds great.

Paul Perry (Frostwave)

Quote from: Simon Owen on January 24, 2006, 05:16:17 PM
The 4.7v zener had gone open circuit.

Suprising how often zeners from that era went open. Pretty disasterous when used for biasing amps, or used to supply a transistorised preamp stage. Some were temperature sensitive.. warm up, open, then cool down ready to bite your ass again :icon_mad:

Simon Owen

I have noticed that this pedal needs a clean supply.  The ripple from the unregulated wall warts donated by my work crush the phasing.  I'm in the process of cloning the mutron phasor II, with an extra 6 stages.  Oh how I will gloat when it is finished as my brother spent £250.00 on an original in October. I am using charge pumps to supply the negative voltages to simplify the PSU requirements.  I've built it modular so I can turn it into a bi-phase if all goes well.