Walwart vs regulated power supply for external soundcard.


2010-12-02 8:21 am
I lost the original walwart for my Extigy external sound card.
I found a few other 12v's laying around, and they worked fine.
While I was looking up power supplies, I had read about people using small 2 amp, 12v regulated power supplies. The cheap walwarts are supposed to be switching power supplies and are not clean.
Is it worth buying a low amperage, low priced 12v regulated power supply?
Power Supply Regulated 3-12 VDC 2A 6-Way 120-536
I am curious if anyone has any experience using a regulated power supply. I have hear of people getting them for thier dacs, with good results.
I don't mind paying the money to squeeze out any sound quality I can.
In my experience it sometimes does, it depends on the device. One quick way to find out is to use a 12V SLA battery. It's a convenient and easy low noise DC source, if you can hear the difference between the SLA and the cheap wall wart, a better supply might be worthwhile.

You could do a lot better than the supply you linked to, it doesn't look that great.


2010-12-02 8:21 am
Any tips on how I determine if a regulated power source is decent quality? I only need 1 amp or less, and that one is 2 amp... The price only goes up as the amperage goes up...
I am not familiar with brands. I have one right now that is "12 volt", but puts out 13.8. I am worried about the extra voltage on a device that is built for 12v, and it's a 7-10 amp and I don't need that much. I mainly use it for testing car audio stuff.....
I will have to set up a test to see if I can hear a difference.
The cheap walwarts are supposed to be switching power supplies and are not clean.

Not all wallwarts are switchers. The obvious way to tell the difference is that transformer supplies feel quite substantial, but switchers feel almost empty. If the supply feels quite solid it's probably not a switcher.

Transformer-type supplies are often unregulated. They run a higher voltage when lightly loaded, this dips down to the nominal voltage when the load approaches the max. output they are intended for. This can be a problem if the device you are running is a light load, you might be exposing it to overvoltage. OTOH it's not uncommon for there to be an onboard regulator, perhaps more than one. Your soundcard has 5V sections, if these run off the supply as opposed to the computer, then there will be a regulator.

You can use a 13.8 volt supply safely by building a 12V regulator on a small PCB (perfboard) using a low-dropout regulator such as the MIC2941.

The board has survived up to now and you seem happy enough with the sound, so you might not want to bother.
The supply you have that puts out 13.8V at 7 to 10A sounds more like a 12V lead acid battery charger. They're marked 12V, as they're made to charge a nominally 12V battery, but they actually supply 13.7 to 13.8V, as that's what you need to charge the battery.

The best supply you'll get is one you make yourself or buy as a kit that's made to supply very low noise DC. It's a project, so again I reccomend you try a battery first to see if it's even worthwhile.


2010-12-02 8:21 am
Thanks for the link, and knowledge...
I am playing around with an old Extigy external sound card I had forgotten about, and found in a box in storage.
It greatly improves the sound quality of my PC over stock, and is a million times better than the internal card on my laptop! This hissing on headphones was really freaking annoying. Now it's dead quiet, and louder too...

My question on power supplies is more of a generalized need for powering anything else I can use on my music server in the future.
I may build a new computer with an ITX small board that uses a laptop style brick PSU. I am going for small and efficient. No fans... I may even try building a carpc that is 12v... I can go solar with it. I am in SoCal...
My current computer is so old I can't find much of anything for it as far as upgrade parts. It works perfect, and sounds great with flac files and the Extigy is used only for the optical output. I am using the internal dac on the cheap yahama receiver. I may get a minidsp in the summer, and I will use that as the dac which will then hook up to the external processor input on the receiver. I can use a linear power supply on the minidsp as well.
Until I improve my speakers, I am not too worried about hearing the improved sound. I am working on speakers right now...

Here is the power supply I currently have...
I just went online, and says it's a low noise linear power supply.
Maybe I should just build a 12v regulator for it as counterculture mentioned.

A retail store I worked for had them in displays for powering some car audio 12v stuff. They were in the warehouse and not used much at all. They were nice enough to let me have one. I use it to test car audio stuff... I guess I had not considered using it, as it's not 12v and didn't want to make more stuff for it. I am going to check a local electronics place that sells bench power supplies. I want to see if they sell low noise regulated supplies.

I will try the battery technique after I fix up my speakers and will better be able to hear any dynamic and quality difference. My speakers are loud and efficient, but lacking in clarity/imaging right now. Do you think my headphones will work well to notice a difference in power supplies? I will try that as well...