How practical is this?

[jimbob]

Im thinking about building "mr EQ" but i only have spst stompswitches from an amp channel selector instead of the ones listed (for the top 3 toggles). Would this work or be worth doing.

[Mark Hammer]

Yeah, it would work, but it may be a waste of stompswitches unless you have an aboding need for these particular resonant boosts.  The other thing is that stompswitches always need space, and to do that you have to have either very few on a smaller chassis, or else a bigger chassis.  I could see 2 on a 1590B with some smart space use, and MAYBE a trio on a 1590BB if you planned out everything perfectly and staggered them, but that strikes me as a whole lot of work for really what amounts to very little real utility.

You'd be better off to go pick up a 16-pin (8 way) dipswitch like you see on the old SansAmp, pop a hole in the chassis of a 1590B, file it out a bit to make room for the dipswitch to pop through the top, and stick a normal DPDT or 3PDT stompswitch in the chassis for bypassing.  With 8 SPST switches, you could not only do what the schem shows, but also change the cap values of some key components.  Much easier to plan pedal (as opposed to PCB) layout for if you ask me.  Hell, for that matter, you've still got a pair of invertors left over.  You could use them to add even more stages, maybe even a preset overdrive that you could bypass/engage with a toggle.

[jimbob]

great ideas- i forgot about space..i think ill hold out till i get the time to ge the parts i need.

thanks Mark

[jimbob]

what about this idea Mark- The spst switches i was going to use  were from a Peavey 3 channel selector. maybe i should use that as the enclosure and drill o hole for a pot and leds, and leave the footswitches alone. It would certainly be enough room.

[nelson]

Its a waste of good switches.

[jimbob]

I would normally agree but could i use spst footswitches for?

[nelson]

Something that needs a footswitch rather than a toggle, one example would be Moosapotomus mod to the Hogs foot, turning a bass boost pedal into an overdrive...handy to have footswitchable. EQ is usually set and left......sell them...... buy some toggles, they are much cheaper. lifting diodes out of a diode clipper............. Many many better uses.

[octafish]

I would normally agree but could i use spst footswitches for?

Superfuzz notch switch

[Mark Hammer]

Some of you have heard this story a bazillion times, so you can tune out now.  In the late 80's, I made myself a rack-mount multi-fx unit with patch-able modules.  For switching, I used the 4016-based CMOS switching modules from the Anderton EPFM books.  Yeah, I know, not straight wire, yadda-yadda-yadda.  But here is where they excel.  These switching modules use a SPST latching footswitch to do their business.  Why is that good?  Because you can easily parallel a momentary SPST footswitch with it for ultra-efficient punch-in/punch-out effect switching.

Case in point.  Classic ZZ Top song: "Cheap Sunglasses".  Classic riff with a ring modulator.  Normally, if one was using a ring modulator pedal with either a FET-based momentary switch or a DPDT/3PDT stompswitch, you'd have to step on the pedal twice to do your 7 or 8 quick notes and go back to regular tone.  If you have an electronic switch that has a parallel latching SPST and momentary SPST switch, you can either step on the latching one if you want the effect to stay on while you shake your spandexed ass at the little ladies in the front row, OR you can put your foot on the momentary switch for the riff and immediately cancel; the effect the moment your foot comes off.  Not something you'd want to use for every effect, but something that comes in pretty handy for some of the more dramatic or cataclysmic effects.  I also used to use it for momentarily feeding my signal to a delay line whose output was always normalled into a mixer.  If I felt like having a note/riff here or there echoed, I'd just step on the momentary switch for those coupla notes, take my foot off and go back to regular playing while the delay line spilled out the repeats one I was done.  Here, I guess, the cardinal example would be some of Jimmy Page's riffs in "Whole Lotta Love".  Very easily accommodated live with this switching system.

And it requires an SPST latching stompswitch.  THAT is why I am telling you this.  There are some very good uses for an SPST stompswitch, so don't waste them.

[jimbob]

I agree - why waste them