putting 2 cicuits in one box?

[southtown]

is this cool? i.e to save on enclosures and jacks ect can u put 2 circuits mounted on a piece of veroboard and run em off the same ebattery... maybe 2 batterys in parrallel so they last longer?

[nelson]

Yep, its cool. Many people do it. Battery wont last as long....might be a good idea to use a toggle switch to have the added option of one or the other circuit or in series.

[Mark Hammer]

This question comes up a couple of times a year, and the answer doesn't really change.

Many of your favourite pedals - with the exception of ultra-simple single-transistor things - already ARE several circuits in one box.  We just THINK of them as one effect because it takes all those parts to make that sound and we're so used to seeing them all in one box with one name.  For instance, many of the fuzzes sold by Boss and especially DOD are really fuzzes and equalizers built into the same board/chassis.

The larger/critical question is not whether it is possible, but whether the options that would make pairing two or more things up into one box:

a) are well planned out
b) possible to fit in the chassis with sufficient room to get at them and use them reliably
c) might result in wiring that could put noise control in jeopardy

A companion question is d) whether a single 9v battery is sufficient to power both circuits.

"D" is easily solvable if you generally use an external power source anyways.  A great many digital pedals that CAN be used with a battery consume more current than 3 or 4 analog pedals.  Of course they don't last long when powered by a puny 9v, and neither would a box containing a couple of analog FX that were not designed for super low current consumption.  If your only need for battery power would be for very short periods, a single 9v as a backup could be fine (some companies design digital FX around being usable with battery power for short periods so they can be demoed in music stores without having to hunt for a wallwart).  I'm not so sure that a pair of 9v batteries in parallel is a great idea unless they are both replaced at the same time.

The greatest advantage of single FX in individual boxes is not only that they have their own batetry but that pedal X can be placed before or after pedal Y, or even placed after pedal Y and Z.  Once you stick an effect into a chassis with something else, you either need to provide some means of being able to change the order of things or else content yourself with a single order.  A single order may be perfectly acceptable for YOUR sound, or if you are a prolific enough builder that you plan to make other pedals with some of the things in your "two-fer" box available elsewhere in your signal chain.  BUT, if this is your only compressor, or only vibrato, or only autowah that you plan on having, is that the ONLY place where you might want to stick it, or can you think of others?

Is there a way of having your cake and eating it too?  Yes.  If the chassis is big enough to support it, you can stick some "normalized" switching jacks on the rear skirt for each of the FX in the box.  In other words, if nothing is plugged into those jacks, it's like they aren't even there.  "A" goes to "B", and you don't have to lift a finger.  If you want to insert something between them, or change their order, you need only insert patch cords into them and they instantly behave AS IF they were two completely independent FX that just *happen* to be sitting in one box.  The battery thing may still be an issue, but the sequence/options thing isn't.

Atthe very least, people often want the capacity to do the following in multiple FX floor boxes:

a) bypass the whole thing, regardless of state of each effect
b) bypass/engage the individual effects
c) insert something between the effects...and bypass that
d) know what's on and what's off

That can all be done easily.  Can it be done in a 1590BB?  Not always.  If your intention is to use a bigger box, you may be able to have it al.  If you had your sights set on a small pedal-board-friendly chassis and you're not using surface-mount technology and custom switches, you may have to forfeit a few choices from the ideal list.

[RDV]

http://www.generalguitargadgets.com/pdf/two_in_one_wiring.pdf

RDV