How Many mA Can Pedals take?

[HolyDirt]

I'm making a power suppy/tranformer that takes in ac electricity and puts out 9vDC and 12vDC through about 7-8 output jacks( 6-7 9VDC, 1 12VDC). The outputs wont be isolated from eachother, so, how many mA should i have running to the outputs? The pedals are eq's, a wah, and a preamp, stuff like that.

[Grandor]

Re: How Many mA Can Pedals take?

I think about 300mA's for the smaller ones and 500mA's for the bigger ones should do it...

[FretFire]

Re: How Many mA Can Pedals take?

Since they won't be isolated, isn't ground loop hum a worry?

[HolyDirt]

Re: How Many mA Can Pedals take?

Since they won't be isolated, isn't ground loop hum a worry?

nope, i really dont care.

[Thames]

Re: How Many mA Can Pedals take?

Hmm...

Id be better if you could find the power consumption of your pedals (mA).

Some simple ones like Overdrives and such draw only 2-10 mA. Some more complex like modulation can draw more.. like 50-100 mA. Some others which are digital like delay and reverb can draw up to 300-500 mA!

I guess a preamp draws more current than a simple pedal. The first thing I'd do is make sure the PSU can handle the the current draw, otherwise you'll fry it.

Ground loops can occur if you dont have isolated outputs in your powersupply. However, lots of commercial ones arent isolated, like Boss, VisualSound, Godlyke, Dunlop and co.

The best isolated PSU is the Voodoo Lab Power Pedal 2.

Im using a Visual Sound 1-Spot and I dont have ground loop.

[aleclee]

Re: How Many mA Can Pedals take?

As long as the PS can supply more than the rated current, it's okay. Assuming reasonable regulation, you don't need to worry about excess current capacity.

[proxy]

Re: How Many mA Can Pedals take?

In most cases you are good as long as you have the correct voltage and enough amps. If I recall the pedal should only draw as much as it needs. As long as you have the correct power supply, there are two types, one for a single pedal and won't vary to the power being drawn and one that will when you daisy chain.

[Kent S.]

Re: How Many mA Can Pedals take?

Hmm...

Id be better if you could find the power consumption of your pedals (mA).

Some simple ones like Overdrives and such draw only 2-10 mA. Some more complex like modulation can draw more.. like 50-100 mA. Some others which are digital like delay and reverb can draw up to 300-500 mA!

I guess a preamp draws more current than a simple pedal. The first thing I'd do is make sure the PSU can handle the the current draw, otherwise you'll fry it.

Ground loops can occur if you dont have isolated outputs in your powersupply. However, lots of commercial ones arent isolated, like Boss, VisualSound, Godlyke, Dunlop and co.

+1 ...

[Kent S.]

Re: How Many mA Can Pedals take?

As long as the PS can supply more than the rated current, it's okay. Assuming reasonable regulation, you don't need to worry about excess current capacity.

+2 ...

[ArtieToo]

Re: How Many mA Can Pedals take?

Your power supply should only have one ground. It should be common to both the 9-volt and 12-volt supplies. It is, by making all the grounds in the power supply rails common to one another, that you help to eliminate ground loops in the audio lines, which is the only place that the concept of a "ground loop" is relative.

Kent, correct me if I'm wrong.

[Kent S.]

Re: How Many mA Can Pedals take?

I'd really have to see what a manufacturer is refering to when they say *isolated* , but yes, generally a central ground point is the way eliminate ground loop problems. A multi tapped transformer (shielded) with a tap at 10VAC and one at 13VAC would work, then take the AC add rectification and filtering. Maybe even higher voltage if regulation is going to be involved, as it would get regulated down to 9.6VDC and 12VDC ... that's power supply design, and that can get a little complicated ...I generally stay away from that and just buy one that fits the bill.