Pedal powering question

C

claxor

Power User
Guys,

I have a few pedals that I'm using with the Axefx 2, and one of them has weird power requirements. I want to use one Voodoo Labs pedal power of some kind to power them all. The weird pedal is the Mooer Slow Engine, which requires 9VDC @ 128 mA. If I connect this pedal to a 9VDC labeled with 100 mA will I damage the pedal? Does the pedal power connection HAVE to be higher than the pedal's requirements? (in this case, should it be connected to a 200 or more mA?)

product

Thanks for your advice!
 
It needs 128. If you give it 100, that's not 128, what it needs.

I just searched google and it seems that no permanent damage will happen to the pedal, but it may not work at all or not work well or may break your power adaptor or may cause a fire from heating up.
 
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Ok, one more question: if you use a cable coupler (connecting two power connections into one pedal) you can double the voltage (two 9VDC's together making one 18VDC connection), but what is the affect on the mA's? Does that double as well? i.e., two 9VDC's @ 100 mA each together making one 18VDC @ 200 mA? Or would it lower the mA to 50 mA?
 
Your pedal says it needs 128 mA of current. That may be a minimum requirement, or it may be a ballpark figure.

DC power supplies are weird things. With no load, they usually put out more voltage than they're rated for. As the pedal draws more current, the voltage drops. Most power supplies are capable of delivering more than their rated current, but at reduced voltage.

What that means is that there may be very little mismatch between your pedal's 128 mA rating and your power supply's 100 mA rating. It's worth a try. It might work just fine, or it might not. In any case, you won't damage your pedal by supplying it with too little power.

As long as the rated voltage matches your pedal—and the polarity matches—you should be okay.
 
claxor said:
Ok, one more question: if you use a cable coupler (connecting two power connections into one pedal) you can double the voltage (two 9VDC's together making one 18VDC connection), but what is the affect on the mA's? Does that double as well? i.e., two 9VDC's @ 100 mA each together making one 18VDC @ 200 mA? Or would it lower the mA to 50 mA?
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I haven't seen a manufactured coupler like that, but if it works as advertised, the mA capacity of the combination will be equal to the mA capacity of the pedal with the lowest rating (in other words, you won't get double the current capacity).
 
Rex said:
I haven't seen a manufactured coupler like that, but if it works as advertised, the mA capacity of the combination will be equal to the mA capacity of the pedal with the lowest rating (in other words, you won't get double the current capacity).
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Meaning, two 9VDC's @ 100 mA each together will make one 18VDC @ 100 mA still?
 
claxor said:
Meaning, two 9VDC's @ 100 mA each together will make one 18VDC @ 100 mA still?
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Yes, but with one great big maybe: Depending on how the power supplies are wired internally, you might not get 18 volts when you connect their outputs together. In fact, you could wind up shorting out the whole mess.

If you have something that needs 18 volts, get an 18-volt power supply. On the other hand, if you're hoping to get better performance out of a 9-volt pedal by hitting it with 18 volts, you run the risk of breaking something permanently.
 
I just had a look at the Mooer website to find out what the Slow Engine is all about. Apparently, it's an envelope modifier that cuts off the attack, similar to the Boss Slow Gear. Gotta say that the manufacturer's description is the funniest bit of Chinese-to-English translation I've seen in a while:

Like a guitarist control the volume knob ,cut off he sound head,
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By the way, the Axe-Fx can do everything the Slow Engine can do. You could save yourself the bother of finding the right power supply for it.
 
claxor said:
Meaning, two 9VDC's @ 100 mA each together will make one 18VDC @ 100 mA still?
Click to expand...
One more maybe...you're talking about connecting the two supplies in series, right? That's the only way that voltage will double—provided there are no internal wiring issues as I mentioned above.

Connecting them in parallel would—in theory—provide double the current without doubling the voltage. But unless both power supplies are very well balanced, you could wind up drawing way more current than the power supplies were designed for, along with the possibility of current flowing backwards in one one the power supplies.

Before I ramble on any further, maybe I should ask how you're planning to connect those power supplies together.
 
Well, for the 18 volts question, I was planning to power a Pigtronix Infinity Looper, which runs at 18 VDC @ 300mA (manual)
 
Unless you're absolutely sure how your power supplies are wired internally, and absolutely sure that they'll play well together, don't connect them together to try for a different output voltage. There are just too many ways that could go bad in a hurry. It's worth it to actually get the right power supply.
 
Rex said:
DC power supplies are weird things. With no load, they usually put out more voltage than they're rated for. As the pedal draws more current, the voltage drops. Most power supplies are capable of delivering more than their rated current, but at reduced voltage.
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This is true for unregulated power supplies. I personally would never use an unregulated power supply with any type of audio circuitry. Their output is not only unregulated but more importantly they usually have poor filtering too which can lead to hum.
 
claxor said:
Guys,

I have a few pedals that I'm using with the Axefx 2, and one of them has weird power requirements. I want to use one Voodoo Labs pedal power of some kind to power them all. The weird pedal is the Mooer Slow Engine, which requires 9VDC @ 128 mA. If I connect this pedal to a 9VDC labeled with 100 mA will I damage the pedal? Does the pedal power connection HAVE to be higher than the pedal's requirements? (in this case, should it be connected to a 200 or more mA?)

product

Thanks for your advice!
Click to expand...

The Pedal Power 2 has two outputs (5 & 6?) that can put out 250mA each. You can also get cables that allow you to connect two outputs into one to double the voltage or the current (one or the other, not both at once), i.e. 9VDC 200mA, or 18VDC 100mA. Or pair 5 & 6 together and you can have 18VDC 250ma or 9VDC 500mA.

That said, you might want to look at the Voodoo Lab website and go through their other products. The Iso 5, Mondo, 4x4, Digital... I'm pretty sure they'll all capable of delivering the 128mA you need through a single output without any trickery required. But of course they all have their differences, so you'll have to figure out which best suits all your requirements. Or look elsewhere even.

As for whether you can underpower it. Well, with a draw that high I'm guessing the pedal is digital. A quick bit of Googling says the original Boss SG-1 needed... 4mA. Unless Mooer have wildly overstated the figure, or have just plain got it wrong... yeah, probably best to just give it what they say it needs.
 
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