Duo-Phase vs Bi-Phase

bengarland

Active member
I'm new to building pedals, so apologies if this is an obvious question...

I ordered the Duo-Phase PCB and it seems that it is missing a couple features of the Bi-Phase (I could be wrong...)

  • Sine/Square wave selector for LFOs
  • Pedal inputs (and accompanying toggle switches)

Is there any way to hack it to add these features?

I'm assuming with no Sine/Square switch that it's hardwired for Sine wave?

Anything else I should know about this particular board / build compared to an original Bi-Phase?

Please be generous with your answers, since I'm new to this and still trying to wrap my head around all of the jargon...

Ben
 
It also seems like there's no knob to select the source for Phasor B Input. Is this able to be done manually based on how the cables are connected on the rear? e.g. how would I patch it so that Phasor A is the Input for Phasor B? Is it as simple as literally running a short 1/4" cable from the Output of A to the Input of B?
 
The Duo-Phase doesn't do square wave LFO or have an expression pedal input.
Technically you could add an isolated switched 1/4" jack to substitute the Rate pot when a pedal was plugged in, but I haven't tried this.

Both of the wiring diagrams in the build doc would give you series operation. (Phaser A > Phaser B)

The diagram on Page 5 is hard wired, so it would always behave this way.

The diagram on Page 6 allows you to use each side independently if you wanted, but when only using the outside pair of In/Out jacks the two phasers would be internally connected (via the switched 1/4" jacks).
 
Like @PedalPCB mentioned above: Has anyone tried to add an expression jack at the Rate Pot?
Yes I have and it works great for me. I do happen to have a suitable expression pedal with I think a 10K pot when I measured it, and that works fine for me. So I guess you gotta check or modify an expression pedal to have a ballpark close pot value to the B25K. I have the expression jack mounted on a switched jack, so when expression pedal is not connected it just works as normal with dashboard pots.
 
Yes I have and it works great for me. I do happen to have a suitable expression pedal with I think a 10K pot when I measured it, and that works fine for me. So I guess you gotta check or modify an expression pedal to have a ballpark close pot value to the B25K. I have the expression jack mounted on a switched jack, so when expression pedal is not connected it just works as normal with dashboard pots.
Could you post some pictures of your completed build with the expression mod? I am thinking about doing this myself.
 
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