Power Supplies -

[cademan]

What is the amperage output of the wall warts that came with your dac and preamp?

Take your volt meter and make sure the voltage is the same and that the output connections are inner positive and outer negative. If things look the same, it shoudn't hurt them any.

As meantioned, the Oscope should tell you what you want to know. Oscope both the wall warts and power supplies and compare the two.

You might get some hum or hash or maybe not. Won't hurt to try.

 

[made in china]

DAC and Tube01 preamp.

!
It'd be hard to believe that the cheapo wall warts that came with these devices, especially a $30 Tube01 preamp would be any better than these. To prove this, I posted the question of how to test them to ensure that they have clean output, and then I'd compare them to the ones that came with the devices. I figured testing was the best way. Still, I'm not sure what to look for when I to test them, which brings me back to my original question!

How much current does your device need?

As for the wall warts....IF they were linear, it's very possible that they have clean output. Doesn't take much to get a linear to be "clean".

 

[Catmanboo]

As for the wall warts....IF they were linear, it's very possible that they have clean output. Doesn't take much to get a linear to be "clean".

Switching supplies, as previously mentioned, internally switch or recognize input voltage to match output voltage required. This circuitry can raise holy hell in radiated noise into the house / building wiring. I.e. the 5 volt switching wall warts for my satellite radio docks MUST be unplugged when not in use if I want to use any AM radios or my HF transceivers which have switchable noise filters, but a bit can still get through. Switching supplies don't use step- down transformers,hence their light weight.

 

[made in china]

Switching supplies, as previously mentioned, internally switch or recognize input voltage to match output voltage required. This circuitry can raise holy hell in radiated noise into the house / building wiring. I.e. the 5 volt switching wall warts for my satellite radio docks MUST be unplugged when not in use if I want to use any AM radios or my HF transceivers which have switchable noise filters, but a bit can still get through. Switching supplies don't use step- down transformers,hence their light weight.

Whilst the modern switching supply can self-select a wide range of input voltages, these PS's are not called "switching" because of that. In fact, the first generations of switchers were either fixed input voltage, or would have a switch you could select.
They are called switching because they "switch" input power off/on at a very high frequency, (many switchers convert input AC to DC prior to the switching stage) which has multiple benefits, mainly that the inductors/transformers they do use can be much smaller. Here's a good read:
https://en.wikipedia.org/wiki/Switched-mode_power_supply

But the frequency at which they switch creates a tremendous amount of noise, both radiated and in the output. Putting a scope on it is OK, but more telling will be how the devices respond to that noise. Every switch mode power supply can cause different issues with different equipment.