Noise from PSU of digital sources

[matt49]

It’s at least theoretically possible that a streamer might inject noise from its PSU into the system. So for instance, if you have a digital source (PC or NAS or streamer) connected by USB or SPDIF to a DAC, some noise from the digital source’s PSU could be carried through the power line of the USB or through the SPDIF cable.

So I’m wondering if the following would be a way to find out whether it’s a real issue in your system: pause the music and turn the amp’s volume up to max. Is there anything coming through the speakers? If not, then noise from the PSU isn’t an issue.

Does this make sense?

I just tried it on my system and couldn't hear a dicky bird.

Matt

 

[abacus]

Noise comes in many forms, and power supplies whether digital or analogue can cause it if poorly designed, however the mechanics are well understood so it should not really be a problem these days, plus most manufactures quote the noise levels of their products so it is easy to compare.

Hope this helps

Bill

 

[matt49]

Noise comes in many forms, and power supplies whether digital or analogue can cause it if poorly designed, however the mechanics are well understood so it should not really be a problem these days, plus most manufactures quote the noise levels of their products so it is easy to compare.

Hope this helps

Bill

I fear you've missed the point.

 

[Frank Harvey]

They could be hearing noise produced by their amplifier's PSU...

 

[unsleepable]

If I raise the volume of the amplifier all the way while in pause, I hear some white noise from the speakers. I have to put my ear right on a speaker to hear it, though.

 

[andyjm]

It’s at least theoretically possible that a streamer might inject noise from its PSU into the system. So for instance, if you have a digital source (PC or NAS or streamer) connected by USB or SPDIF to a DAC, some noise from the digital source’s PSU could be carried through the power line of the USB or through the SPDIF cable.

So I’m wondering if the following would be a way to find out whether it’s a real issue in your system: pause the music and turn the amp’s volume up to max. Is there anything coming through the speakers? If not, then noise from the PSU isn’t an issue.

Does this make sense?

I just tried it on my system and couldn't hear a dicky bird.

Matt

It makes perfect sense - by definition, if you cant hear any noise, then there isn't any.

 

[matt49]

It’s at least theoretically possible that a streamer might inject noise from its PSU into the system. So for instance, if you have a digital source (PC or NAS or streamer) connected by USB or SPDIF to a DAC, some noise from the digital source’s PSU could be carried through the power line of the USB or through the SPDIF cable.

So I’m wondering if the following would be a way to find out whether it’s a real issue in your system: pause the music and turn the amp’s volume up to max. Is there anything coming through the speakers? If not, then noise from the PSU isn’t an issue.

Does this make sense?

I just tried it on my system and couldn't hear a dicky bird.

Matt

It makes perfect sense - by definition, if you cant hear any noise, then there isn't any.

Yes, that's what I thought. Good news then: another theoretical worry I can cross off my list!



Matt

 

[davedotco]

It’s at least theoretically possible that a streamer might inject noise from its PSU into the system. So for instance, if you have a digital source (PC or NAS or streamer) connected by USB or SPDIF to a DAC, some noise from the digital source’s PSU could be carried through the power line of the USB or through the SPDIF cable.

So I’m wondering if the following would be a way to find out whether it’s a real issue in your system: pause the music and turn the amp’s volume up to max. Is there anything coming through the speakers? If not, then noise from the PSU isn’t an issue.

Does this make sense?

I just tried it on my system and couldn't hear a dicky bird.

Matt

It makes perfect sense - by definition, if you cant hear any noise, then there isn't any.

Yes, that's what I thought. Good news then: another theoretical worry I can cross off my list!



Matt

Of course a noise signal that is inaudible in it's own right could have an effect on the music signal in some way, some kind of intermodulation perhaps.

Just playing devils advocate here, for example, out of band noise 'draining' a dacs power supply to the detriment of the music signal..... :?

Happy to be shot down on this one.

Anyway Matt, don't you have an 'upgraded' psu for one of your Sonoses (Soni?).

You should be telling us...........

 

[matt49]

Of course a noise signal that is inaudible in it's own right could have an effect on the music signal in some way, some kind of intermodulation perhaps.

Just playing devils advocate here, for example, out of band noise 'draining' a dacs power supply to the detriment of the music signal..... :?

Happy to be shot down on this one.

Anyway Matt, don't you have an 'upgraded' psu for one of your Sonoses (Soni?).

You should be telling us...........

I may have unintentionally given the impression that I have a problem with noise in the system. As far as I know, I don't. I was really just interested in establishing whether any noise that might be there and might be subtly degrading the SQ, could be heard by pausing the music and turning the wick up to max.

The background is that I'm trying to eke the most that I can out of a simple front end consisting of a NAS drive connected by USB to the Devialet. USB cable contains a 5V power line, and it's possible (in theory at least) for noise from the upstream device to be carried down the power line into the DAC (though if the DAC is properly galvanically isolated this ought not to be a problem).

So as you see, just a little experiment to see how clean the digital source is.

Anyway Matt, don't you have an 'upgraded' psu for one of your Sonoses (Soni?).

You should be telling us...........

Yes, Dave, though the one with the upgraded PSU is currently at the holiday cottage (for rather boring reasons I won't go into). The one I'm using here is the 'standard' Cullen-modded Connect.

So I have two sources going into the Dev: NAS via USB and modded Sonos Connect via SPDIF. I can run them in parallel and switch instantaneously between them. I suspect it's not really a fair test though, because the NAS via USB sounds louder; I'd need to level match the sources.

If you want to get classical with the plural of Sonos, it should be 'Sonoi' (c.p. 'hoi polloi').

Matt

 

[andyjm]

Of course a noise signal that is inaudible in it's own right could have an effect on the music signal in some way, some kind of intermodulation perhaps.

Just playing devils advocate here, for example, out of band noise 'draining' a dacs power supply to the detriment of the music signal..... :?

Happy to be shot down on this one.

While it is possible, it is unlikely. There are all sorts of scenarios you could come up with, but given most modern amps are pretty well designed, if you can't hear any noise from the speakers then the EMI coming from another PSU is probably having no effect.

 

[davedotco]

Of course a noise signal that is inaudible in it's own right could have an effect on the music signal in some way, some kind of intermodulation perhaps.

Just playing devils advocate here, for example, out of band noise 'draining' a dacs power supply to the detriment of the music signal..... :?

Happy to be shot down on this one.

While it is possible, it is unlikely. There are all sorts of scenarios you could come up with, but given most modern amps are pretty well designed, if you can't hear any noise from the speakers then the EMI coming from another PSU is probably having no effect.

Good. I find myself troubled by 'prospective' issues, just my nature I think.

On another thread I explained how I hear the image shift if speaker cables are of different lengths, this is 'real' but of course occurs only if I know the lengths are different. All in the mind of course, but even knowing and understanding this I still hear the image shift.

Crazy huh......... :doh:

Matt. Maybe Sonos has latin roots, not having a classical education, I wouldn't know...... :?

 

[matt49]

Matt. Maybe Sonos has latin roots, not having a classical education, I wouldn't know...... :?

Yes, Sonos is an invented word consisting of a Latin root and a Greek ending. It looks like the Latin sonus (plural soni), meaning 'sound'. But they've given it a Greek -os ending, the plural form of which would be -oi (which is why I suggested sonoi on the analogy of 'oi polloi' , a transliteration from Greek).

I hope Greek and Latin count as 'hard' subjects in your view!

Matt

 

[davedotco]

Matt. Maybe Sonos has latin roots, not having a classical education, I wouldn't know...... :?

Yes, Sonos is an invented word consisting of a Latin root and a Greek ending. It looks like the Latin sonus (plural soni), meaning 'sound'. But they've given it a Greek -os ending, the plural form of which would be -oi (which is why I suggested sonoi on the analogy of 'oi polloi' , a transliteration from Greek).

I hope Greek and Latin count as 'hard' subjects in your view!

Matt

Very much so in every sense.

I managed just a couple of years of elementary latin, but then I was at a 'technical' grammar school, all maths, science and modern languages.

I would have loved a classical education but as we all know, proper education is wasted on the young.

 

[wilro15]

My power amps seem to produce a very slight hiss/crackle sound. You can only hear it with your ear close to the speaker with no music playing. It still happens if I disconnect the DAC/preamp too so fairly sure it is power amps.

Have also tried an "expensive" mains cable (Copperline Alpha) and an RFI/EMI filter multiplug but I still get it.

Its one of those little things that gnaws away at the back of my head because I know it is there.