DAC PSU required?

[muggo]

I've just bought an SMSL M3 DAC/amp for driving my headphones. It cost £46 on eBay.
My main system has no headphone socket so I've setup another Pi Mk 1 running piCorePlayer 3.0.1. Squeezelite is ver 1.8.4-762. Output setting is iec958:CARD=DAC,DEV=0. Connection is via USB.
It sounds quite good, but I suspect my Sennheiser HD470 headphones are the weak link.

However, if I plug an external PSU (2.1 amp) into the DAC, I can't tell any improvement in the sound. The DAC is obviously being powered by the Pi (2 amp input), but I'd have thought a PSU running to the DAC should sound better.
Can the Pi be configured to supply signal only to the DAC? I imagine separating power & signal would give a better sound.
Any advice welcome.

[Julf]

I'd have thought a PSU running to the DAC should sound better.

Why?

I imagine separating power & signal would give a better sound.

Again - what makes you imagine that?

Most DACs have more than adequate internal power regulation/filtering.

[muggo]

Why?



Again - what makes you imagine that?

Most DACs have more than adequate internal power regulation/filtering.

I thought it was generally accepted wisdom that decent power supplies lead to better sound.

[Julf]

I thought it was generally accepted wisdom that decent power supplies lead to better sound.

Pretty much all "generally accepted wisdoms" tend to be wrong. Especially audiophile ones.

[garym]

I thought it was generally accepted wisdom that decent power supplies lead to better sound.

Only by the folks that sell overpriced and unnecessary power supplies (and a few of their victims that suffer from the normal human nature of "rationalization" based on their post purchase biases).

[alfista]

I thought it was generally accepted wisdom that decent power supplies lead to better sound.

What makes you believe the DAC doesn't have a decent enough power supply then?

[muggo]

What makes you believe the DAC doesn't have a decent enough power supply then?

Because it cost £46 & is made in China so I imagine some corners will have been cut.
It has a USB port for signal & also one for power. Why would it have two if one was enough?
Anyway, my query was about if a Pi can just send signal & not power. The thread has been diverted into whether power supplies in hifi are a waste of time.

[garym]

Because it cost £46 & is made in China so I imagine some corners will have been cut.
It has a USB port for signal & also one for power. Why would it have two if one was enough?
Anyway, my query was about if a Pi can just send signal & not power. The thread has been diverted into whether power supplies in hifi are a waste of time.

You should change the thread title. It is asking whether a PSU is required for a DAC. It turns out that is not your question. Probably should mention Pi in your subject and be more specific in order to get Pi users to notice that they might have something to add to thread.

[muggo]

You should change the thread title. It is asking whether a PSU is required for a DAC. It turns out that is not your question. Probably should mention Pi in your subject and be more specific in order to get Pi users to notice that they might have something to add to thread.

Done

[Man in a van]

@muggo

One can buy usb devices that block the power supply part and pass through only the data and ground.

Some dacs need the power supply to "handshake" with the computer.

It is possible to insert a piece of tape over the power part of the usb connector to stop the power supply.

Google is your friend.

[muggo]

@muggo

One can buy usb devices that block the power supply part and pass through only the data and ground.

Some dacs need the power supply to "handshake" with the computer.

It is possible to insert a piece of tape over the power part of the usb connector to stop the power supply.

Google is your friend.

Thank you for the advice.