What does the stereo spread knob do on the mono flanger?

[Joe Bfstplk]

Question in title:
What does the stereo spread knob do on the mono flanger?

 

[sprint]

Nothing as far as I can hear/see on a stereo width meter

edit - it does seem to yield some phase cancellaton behaviour when I move the knob around but it's not adding any width.

 

[Larzz]

"it's a trap..."

 

[Bakerman]

Mono types use a stereo block configuration, like stereo types but with LFO phase 0°. Stereo spread does the same thing as in other types: sets the output panning of the two delay lines generated from input L & R signals. With a mono input signal and LFO phase 0° this doesn't really do anything (except reduce the true mix % when pan absolute value > 100% due to inverted signal in opposite channel). To hear any* other effects from stereo spread adjustments, a stereo input signal and/or nonzero LFO phase value is required.

*Phase reverse = left or right will also make stereo spread have an audible impact, but without one or both of the other elements above, the effect will be identical to some mix/level adjustment and/or opposite phase reverse setting.