Mini phase 45

I started this mini Phase 45 so long ago I cant remember when. It wasn’t working, so I pushed aside and forgot about it. I found it again, and decided I would get it working.

There was sound but no phasing when the circuit was engaged. My first guess: the oscillator was not oscillating. I tested this idea with the multimeter. Turns out the voltage was cycling at IC 2 pin 7. So much for that theory!

If the oscillator is oscillating then, the control voltage was not changing the phase! This theory suggested the the two FETs were not doing their job. When FETs are a problem its often the pins!

Turns out the board was designed to use 2N5457 the original Phase 45 used 2N5952 which is what I had used. Looking up the parts I found the pins are backwards!

  • 2N5457 – DSG
  • 2N5952 – GSD

After a few minutes with the soldering iron and the desoldering tool we had some phasing!

I got this board from I’d recommend it if you wanted to fit a Phase 45 into a small space. Overall I’m not a fan of building pedals into 1590A sized enclosures.





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