2 pedals, one enclosure...one 9v?

[tomer629]

If I build 2 pcbs in one enclosure, can they share 1 9v battery? Will either pcb be starved for power (like a voltage sag mod) when both are turned on, or will it just drain the battery faster, and give each pedal all the power they need?

[bluebunny]

Go for it.  The battery doesn't know what it's connected to - one circuit or eight (it's all one circuit, btw).  Assuming the power requirements of that whole circuit can be met by the battery, you're good to go.

[Jdansti]

What the bunny said. Two boards effect circuits will drain your battery faster than one, but if the power consumption of the boards is like 99% of the circuits you find on this forum, your battery will still last a very long time.

One way to think about it is let's say that you have a Tube Screamer circuit and it draws X mA. Two Tube Screamers will draw 2X mA. If X=10mA, then both circuits being powered simultaneously would draw 20mA. That's still pretty low power consumption. However, if you connected 100 Tube Screamers to one power source, they would collectively draw 1000mA (1A) which would be a substantial draw on a 9V battery.

[chumbox]

As others have mentioned, go for it.  Like a lot of others I've done it and it works totally fine.  Depending on what you put in the enclosure it will often draw less current than just one super whizz bang delay pedal would.

[GiovannyS10]

I really do not recommend you use battery for feed two pedals same time.  At least, of course, if you have money to spend with new alkaline batteries.  But answering your question, the others said all. If you want, you can. But the battery will go faster.

I would will use a dc power supply. 

[tomer629]

Thanks for all the responses.

I am not concerned with battery life, as long as both pedals have all the power they need to function properly.

I looked at the pcb's I have and am thinking of going with a bluesbreaker + ocd. Both AION pcbs. The OCD uses a charge pump to get to 18volts. Would I still be able to have both pedals on at the same time? Im really clueless as to how much power a typical stompbox draws, and how much a 9v can provide. Hoping to learn more once I get my multimeter from amazon.

[PRR]

> 2 pcbs in one enclosure, can they share 1 9v battery?

If I have two headlights in my car, can they share one 12V battery?

Yes, it is possible to over-do it. The off-road deer-hunting truck with 37 spotlights in all directions may flatten its battery fast, or even burn-up wires. Two hungry effects on one battery will be double the hunger and half the battery life. But many-many effects don't use much power. If you have been living on batteries, you probably already know which ones need a new batt every break and which ones only need a batt for Christmas.

[antonis]

I would will use a dc power supply.

Maybe with a little care for avoiding ground loops and hum-noise problems..

[duck_arse]

if all aion pedals use 4k7 for the led CLR, you can save yourself some juice just by doubling or tripling+ those values (to personal taste/functionallity, natch).

[tomer629]

if all aion pedals use 4k7 for the led CLR, you can save yourself some juice just by doubling or tripling+ those values (to personal taste/functionallity, natch).

I considered this, but figured the power saved would be negligible. Anyone know if this makes a noticeable difference? Are we talking .1% power saving or 5% or more?
I'm not familiar with how much power a LED draws and how that factors into brightness.

Is there a way to test how much power a LED is drawing with a multimeter?

[strassercaster]

Man its not that i hate batteries at all. I hate buying them. I have spent thousands on batteries in my life hell i spend almost 100 bucks at xmas with three kids ha ha. There is no cleaner power than a battery but now days a onepot is so cheap and for 30 bucks you can get a one spot and a daisy chain . Delays chorus and flange use a lot of juice. univibes use a ton with the light bulb. I dont think the charge pump will be too bad depending on the micro amps being drawn by the circuit.circuit Changing the voltage  with a charge pump probably wastes 5-10 percent of your power via leakage and draw from the charge pump and assoiciated components but its not going to make much of a difference if its a circuit that has minimal micro amps. my guess would be for example you would get 15 hours at 9v you would probably get 13/14 hours via charge pump for the same circuit at 18 volts.

[duck_arse]

ask Mr Ohm. he says that you tell the led how much power it is going to draw, via the choice of resistor. let's say your led drops 1V7, which it will do no matter what current you put through it*. so you've got to drop 9V - 1V7 across A resistor. how bright do you want the led?

work out the current (I = E/R) when the resistor is 4k7. then work out for a 22k, like I use with a superbright. now assume your pedal (sans led current) draws 2mA.

is the saving worth it?

and to test how much the led is drawing, measure the voltage across the current limit resistor, and again ask Mr. Ohm.


* within specs, natch.