Do your PSU's hum or buzz?

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Post by JohnLRice » Tue Oct 07, 2008 11:20 pm

Muff, matthias and all,

I stand corrected! :oops: My Power One is not 'dead quiet' :rip: as I said earlier. It's only 'near dead quiet'! :ghost:

To hear it's faint hum took being in my studio at 2AM (no traffic) with nothing else on, holding my breath and putting my ear in an empty module opening.

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Post by flight » Fri Oct 10, 2008 12:08 am

Okay, I did a little more research. Apparently, if you want a PSU you can pick up with one or both hands, it's gonna hum a bit. The eddy currents and hysteresis present in the transformer require substantial reinforcement to overcome so, aside from acoustic shielding, there will be noise. The level is also somewhat relative to the current capacity of the unit (assuming equal build quality). The warning sign of a failing winding is the harsh buzz.

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Post by goiks » Thu Nov 13, 2008 12:03 pm

whew. that's a relief. i was hoping a slight hum was normal. isolating the ps from the wooden case (mousepad material) also seems to help to not amplify the vibrations through the wood. i recently built two cases w/secondhand powerone hbb-1.5 power supplies ($16 each, with shipping!), and they both hum. now i'll feel ok building the third.

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Re: Do your PSU's hum or buzz?

Post by XPump » Tue Feb 25, 2020 2:56 am

Cheap DIY Pwr?

I had a bunch of not too ancient 19vdc switching power supplies from laptops which
where sitting around unused.
I refurbished a couple by using Step Down Regulators from from Parts Express
7A DC 60V Adjustable Step Down Regulator NC Power S 320-615

Put this all in a 8”x5”x 13”plastic housing

I like the built Volt/Current displays
I have put a 3amp amp draw on it for some 20 mins and its worked fine so far
with no discernible noise in modules.
The Laptop power supply’s rated +5amps..regulators are rated for 7 Amps
so its good for a couple 168hp rows .
I’m curious to see how it goes after a few hours but haven't had the time yet

Im considering adding 1 or 2 small fans .. I think using 120AC fans will introduce less noise than the DC versions eating up the amps
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Re: Do your PSU's hum or buzz?

Post by EATyourGUITAR » Thu Feb 27, 2020 7:04 am

besides the necrobump...yeah I settled on laptop bricks. why? because they were %100 FREE. and I can put linear regulators on 15v DC no problem. not a lot of heat to get from 15v to 12v. I used this connector

I don't think I would use that step down board from parts express. I prefer to just buy a linear regulator and heatsink. I design my own PCB and bus board because it just works out better than anything I could buy that fits my case. I have only 6U but I fit a power supply, bus board, long spring reverb in a portable case.

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