Can I power 2 OD circuits with one battery?

[Ben Lyman]

A key player wants me to build 2 independent distortion pedals in one box with 2 input jacks and 2 output jacks for his split keys/dual amp setup.
Can I hook both circuit boards to one battery snap?
Or do I need to install two battery snaps?

[GoranP]

that's what i used to do a lot, separate circuits in one enclosure, shared dc jack. once in a while you might want to look into power filtering and/or decoupling.

[duck_arse]

if you put an R/C filter in the supply of each effect, it will be one less thing to worry about if the squeals start.

[Mark Hammer]

Yes.  Do note the current consumption of each circuit, since your battery may not last long.  Most 2-transistor distortions don't need much.  I suppose the only real concern would be assuring that the dynamic response of one circuit is impacted on by the current draw of the other.  But that would depend on the specific circuits involved.

Probably the more critical matter is keeping the leads from the one away from the other so that oscillation doesn't develop.  As distortions, they ARE both higher gain circuits, which elevates the risk if you aren't careful.

[Ben Lyman]

Ok, thanks. I was thinking of using the Electra Distortion or Ursa Minor from Small Bear or a FF because those are the only 3 effects I've ever made.
Iwas going to run a 1k res series w/100uF cap off each +9v lead for each circuit. Is that "decoupling"?
I could just install a DC Jack and tell the guy it's the only way to run it, if you guys think that's better.

[esdiezy28]

I believe he means to run those those leads with the V+ in different directions, so they arent near each other inside. A 1k resistor in series, with a 100 if cap will filter out some power supply sound issues you might have, but I'm not sure if that is ideal

[MrStab]

1k would only give you 9mA per circuit, which is probably fine for the most part, but be careful not to run any LEDs from the circuit-sides of those resistors. 100 ohms is probably enough, to be honest.

you should also consider putting a small non-polar film or ceramic cap in parallel with the 100uF cap, to help with the poor impedance of electrolytic caps. loads of people don't bother with that, but it can help with stubborn voltage sags.

[Ben Lyman]

Thanks MrStab, I am still trying to learn how to figure out how to calculate the proper resistor values for this part of my pedals. I think (hope) I am starting to get it now.
btw, JUNKATRON! JUNKATRON! Love it!

[MrStab]

no problem Ben. thanks a lot for checking out the tune! didn't expect that! lol

more often than not, i'd say people omit any series resistance with the power supply to effects, but especially in a 2-in-1 effect, i'd say it's a very good practise to prevent problems that may arise if the same adapter is used for even more effects or if the battery starts dying.

Ohm's Law! it's so universal it's almost annoying.

[duck_arse]

Ohm's Law! it's so universal it's almost annoying.

imagine how tough life was before the law was passed.

[MrStab]

i guess they didn't always need it, back when they had.... Tube Steamers.

*tumbleweed*

[PRR]

>> Ohm's Law! it's so universal it's almost annoying.
> i guess they didn't always need it, back when they had.... Tube Steamers.

Ohm's Law applies to steam in tubes too.

(Only at VERY low velocity; at some point fluids go turbulent and an exact solution is impossible. That is why nobody believed Georg Ohm at first; few fluid problems are as simple as electric resistance at practical current levels.)

[MrStab]

i definitely wasn't expecting that ^. makes sense with my limited understanding of the "everything is a resistor" thing and conductivity of water.

i'll need to read more on that transitional period in understanding between steam/pure-mechanical and electronic technology, i don't doubt it shaped the direction and expectations of experiments (for better or for worse). actually, it's vaguely relevant to this very day; with a lot of predictions in Back to the Future Part II being based on paradigms that would inevitably be phased out. lol

/deviation