Please help me find a power supply

A

Adam P

Well-known member
I have a "lunchbox"-style rack unit with several digital delay and digital reverb units mounted in it, except unlike most lunchboxes which provide power to the units, this one is merely a frame, and each unit runs off its own wall wart power supply. I bought the whole thing used and it came with one wall wart adaptor. I picked up a daisy chain power cable from pedalboard.com so that I could run more than one unit simultaneously, but erroneously forgot to check the amp draw of each unit. Turns out that each one runs 15v 400ma, and my power supply was only rated for 15v 600ma, so running two units at the same time fried it pretty quickly.

I have a total of three each of the delay and reverb units that I'd like to be able to run all at once, if possible. They're all 15v DC 400ma. The three reverb units say 8w each, while the delays are 2w each. I'm thinking that a 15v 3 amp AC adaptor would work, but I'm not sure if this is correct, and I'm also not sure how the wattage comes into play.

Can someone direct me to an inexpensive AC adaptor that will power my units without frying them? Thanks.
 
search for mouser or parts express online

call them up and have one of their customer service techs hook you up...
 
I searched their sites but wasn't able to find much. This is partially due to the fact that I don't know exactly what it is I'm after. Thanks though.

Any other thoughts?
 
Adam P said:
I have a total of three each of the delay and reverb units that I'd like to be able to run all at once, if possible. They're all 15v DC 400ma. The three reverb units say 8w each, while the delays are 2w each. I'm thinking that a 15v 3 amp AC adaptor would work, but I'm not sure if this is correct, and I'm also not sure how the wattage comes into play.
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The 8 watt reverb units would actually draw closer to half an amp, so the existing supply is a bit underpowered for these... while the delays power would be more than adequate for the 200 milliamps that these draw.

The total wattage of all units would be (8*3)+(2*3)=30 watts
30 (watts) / 15 (volts) = 2 (amps)

So yes... a 15 volt, 3 amp supply would be perfect
 
Adam P said:
I have a "lunchbox"-style rack unit with several digital delay and digital reverb units mounted in it, except unlike most lunchboxes which provide power to the units, this one is merely a frame, and each unit runs off its own wall wart power supply. I bought the whole thing used and it came with one wall wart adaptor. I picked up a daisy chain power cable from pedalboard.com so that I could run more than one unit simultaneously, but erroneously forgot to check the amp draw of each unit. Turns out that each one runs 15v 400ma, and my power supply was only rated for 15v 600ma, so running two units at the same time fried it pretty quickly.

I have a total of three each of the delay and reverb units that I'd like to be able to run all at once, if possible. They're all 15v DC 400ma. The three reverb units say 8w each, while the delays are 2w each. I'm thinking that a 15v 3 amp AC adaptor would work, but I'm not sure if this is correct, and I'm also not sure how the wattage comes into play.

Can someone direct me to an inexpensive AC adaptor that will power my units without frying them? Thanks.
Click to expand...


8W & 2W are ~533mA & 133mA respectively. Therefore the total current draw should only be ~2A (all units powered).

Power(watts)÷E (voltage, this case 15v) = I (current). After doing the math, I'd'recommend (at least) double the current value when selecting the power supply. This will reduce how warm the supply will get when powering all 6 effects
 
Thanks for both of your replies.

When I do a Google search for 15v 3a AC adapters, most of what I see are units made for Toshiba laptops. Is there any reason that one of these wouldn't work, or are all 15v 3a AC adapters created "equal", for lack of a better term?

If a power supply for a laptop would work, what are the potential ramifications of using the power supply from my old laptop, which is 20v as opposed to the 15v required by the units?

Thanks again.
 
There's a company named mPATHX (mPATHX.com) which is meant to replace wall warts and is rack mountable. I imagine it is rather expensive (and may be overkill for your needs), but I don't know that for sure. May be worth checking out at least.
 
Adam P said:
Thanks for both of your replies.

When I do a Google search for 15v 3a AC adapters, most of what I see are units made for Toshiba laptops. Is there any reason that one of these wouldn't work, or are all 15v 3a AC adapters created "equal", for lack of a better term?

If a power supply for a laptop would work, what are the potential ramifications of using the power supply from my old laptop, which is 20v as opposed to the 15v required by the units?

Thanks again.
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15V is 15V, as long as it can supply the current. Although one supply might provide cleaner power than other, it's hard to say without testing. Whether or not that matters is up to the boxes receiving the power.

Don't feed the units 20V though. Best case scenario, their regulators will shed the extra voltage as excess heat (5V * 2A = 10W). Worst case, the units can't handle the extra voltage, and you fry something.

You could build an external regulator to drop the voltage, but once you get to that point, you might as well build a power supply at the proper voltage.
 
Wow. While that unit certainly does look intriguing, I suspect it might be a bit overkill for what I'm looking for at present. Definitely something to keep in the back of my mind though.

Edit: Thanks, Jon.
 
MOFO Pro said:
:D By a razer slim margin of 18 hrs... damn that was close :rolleyes:
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Not too bad....I posted this from my blackberry and let me tell yah, it ain't that easy. The last time I did it it took like 20hrs. It would appear that I'm getting better. :):p;)
 
Simman said:
Not too bad....I posted this from my blackberry and let me tell yah, it ain't that easy. The last time I did it it took like 20hrs. It would appear that I'm getting better. :):p;)
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I tried to access this site from my blackberry just once... I just plain gave up...
 
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