Looking for a wide sweep 125B sized flanger

Started by Kevin Mitchell, January 24, 2020, 02:51:41 PM

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Kevin Mitchell

I want a flanger that has a very wide sweep - so wide that you don't know if it's ever going to end.
And it would be awesome if it fits into a 125 enclosure (my pedal board theme). I'm not apposed to working up a layout but it would have to be practical for though-hole DIY stuff - and fit in one box  :icon_lol:

Lay em' on me!

-KM
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Mark Hammer

Hi Kevin,

I'm going to suggest that whatever it is, it ought to have a 12-15V supply voltage.  I own a couple of Boss BF-1 flangers.  The chassis indicates a 9V external supply, but the service notes indicate a 12V supply.  It works fine with 9V, but has a wider sweep with 12V.  You will also want something with a current boost between the clock source and the clock pins on the BBD, to overcome any input capacitance on the pins.  With many standard designs that use a 310x clock chip and MN3x07 BBD, the input capacitance on the BBD's clock pins puts limits on how fast you can clock it in the absence of such buffering. 

ElectricDruid

I agree with what Mark said, and so I'd recommend things that *don't* use the MN3102 clock chip. The datasheet for that gives a 200KHz max, whereas I know from having tried it that the MN3207 can easily go to 500KHz before it starts to lose volume (x2.5 higher at least). It can go higher still if you're willing to accept a bit of volume loss (i.e. not such deep notches at the very top end). Pedals that can push it that far tend to be based on multiple paralleled stages of some CMOS buffering the clock, so that's what I'd look for. If you can get 25KHz to 750KHz you're on a 30:1 sweep which is up there with the best. 20KHz to 800KHz gives a 40:1 sweep, but 20KHz means the filters will either be very dark or the clock will be quite audible. So you choose your compromises.

I settled for a 20:1 sweep of 25KHz to 500KHz with my own Flangelicious design, for several technical reasons, including some of those above! If I can improve that in the future, I will, but it's not straight-forward.

Tom

Mark Hammer

One of my New Year's resolutions is to finally finish my PAiA Hyperflange.  IIRC, it has a sweep of 88:1.  :icon_eek:

I suppose it goes without saying that a "wider" sweep necessarily involves doing things to produce much shorter delay times.   That is, the extra "width" comes from raising the ceiling.  Low clock frequencies are easy to produce, and delays longer than 20msec don't really yield anything that one might consider flanging.  So increasing width means moving beyond the 1msec ceiling that the BF-2 is saddled with.