In other words, what the FET gates see is a combination of the default bias setting from the trimmer, PLUS whatever the LFO adds on top of that. That resistor sets the amount of LFO current fed to the FETs, and is summed with what comes off the trimpot. This will provide variable offset to move where the phasing occurs in the spectrum, from lower and gurgly to higher and swirly.Ģ) Right beside that 1M resistor is a 3M9 resistor connecting the 15uf cap to the same 'blue' trace where the 1M resistor goes. Replace that with a 510k fixed resistor in series with a 500 pot, using as a variable resistance.

So here are some options for achieving a broader range of sounds out of the basic design, and making more like what you get with a 3 or 4-knob phaser.ġ) There is a 1M resistor coming off the trimpot, feeding the gates of all the FETs. The resonance/feedback was also a compromise setting, as was the range of where the sweep occurred. The width of the sweep was a compromise for something that worked reasonable well for fastest and slowest speeds (one usually wants a narrower sweep for faster speeds). As such it was designed to provide a number of compromises.