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How to Modify SMPS Output Voltage

I’ve got a number of iFi iPower and iPowerX power supplies with factory set voltages of 5V, 12, and 15V. I’m tying to power two devices that require 3.6V and 7.6V. Currently I am using some cheap store bought voltage regulators to take the iFi 12V power supplies down to the desired voltages. I got to thinking that if I could modify the iFi output voltages to the desired voltages, then I wouldn’t need the cheap voltage regulators - fewer lower quality devices in the power chain should improve sound quality. Does anyone know how to do this? I contacted iFi and they said their devices aren’t adjustable nor will they sell me custom voltage units. On some power supplies, it’s as easy as opening the device and adjusting a pot. In other cases, you can switch out a resistor to modify the voltage. I’m okay with voiding the warranty. Does anyone know if this can be done and if so, how to do it? Thank you.

128x128mkgus

Showing 3 responses by erik_squires

erik_squires
15,662 posts
 

I guess my big question was why a PS1 needed to be upgraded. :-)

As a hobbyist though you may have a lot more fun/success if you built your own linear power supplies.  A good pi filter and regulators can do marvels for noise.

erik_squires
15,662 posts
 

Why are you getting so expensive / exotic with these supplies?  An off the shelf wall wart would be $30 or less.  You don't need super low noise supplies.

You are right.  A VR would be a much better solution than a R divider, but depends on current draws. 

erik_squires
15,662 posts
 

DIYaudio is a better source for these types of questions.

What exactly are the devices you are trying to power? They may be OK with slightly higher input voltages.

Of course a cheap solution is a resistive voltage divider. I’m sure you can find calculators online that let you take into account the device current.

If you are willing to take things apart then build your own linear power supply.

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