Is it possible for a power supply to affect sound quality?

[Superdad]

On 6/18/2020 at 4:55 PM, SJK said:

Can a linear supply actually make any difference? 

 

44 minutes ago, StephenJK said:

If you, and so many others actually went back and read the OP, it was with a detailed and specific focus on outboard linear power supplies only, not that you seem to know or care. 

 

And, how any linear power supply based on an old school breadboard diode/filter network could or would compare to some overpriced boutique variation that does the same thing for tens or hundreds the cost. 

 

Hi Stephen:

As I stated several times prior, digital audio circuits respond VERY favorably to power supplies with very low broadband output impedance. 

Your "old school" diode/filter network will not compare in that regard to some of the better offerings focused on that.

You can read a bit about our designs at: https://uptoneaudio.com/products/js-2-linear-power-supply or https://uptoneaudio.com/products/ultracap-lps-1-2

(We are not into "snake oil" when it comes to power supply design. If we were we would not spend so much to build them!)

Or you can read a this good post from Paul Hynes:

 

[fas42]

Refreshed my awareness of a good book on the subject, which details the degree of precision one has to keep in mind to properly understand and measure what's going on in circuits, https://www.picotest.com/images/download/power-intergity-book-sample.pdf

 

.

 

 

[Clockmeister]

Gents

 

It's only a power supply, everyone is entitled to there own views whether for or agsinst  the premise, Some quote from experience others rebutt due to their own thoughts and beliefs.

 

My personal experience of building numerous psu' s and the resultant listening indicates to me it is a worthwhile venture, others may not feel inclined to do so.  No problem personal choice. Do I get offended by this ? Hello no people will do what they feel us correct for them. Life is to short to get overly worried about a transformer in a much metal box

 

[feelingears]

Well if anyone feels more voices/votes is more legit, then +1 for power. Paying for quality power has paid enormous emotional sonic dividends over the years. In fact I have considered power the most important factor in my system for a long time, and power especially opened my ears with digital signal quality five or six years ago. YMMV.

[Abtr]

On 6/25/2020 at 7:35 PM, John Dyson said:

Assuming product quality isn't perfect, and is the reason why noise suppression might be helpful -- it might be a good thing to put a slight distance between the device and the suppression filter (ferrite) -- just because the equipment is probably not well shielded.

...

Hi John. I use a 7.5V SMPS to provide clean 5V power to the USB input of a DDC (Schiit Eitr). I inserted a small, LT3045 based, 5V regulator board (ldovr.com) in the output power cable of the SMPS at about 4 inches from the end. Do you think a ferrite bead should be placed before, or after the regulator board? Thanks.

[John Dyson]

42 minutes ago, Abtr said:

Hi John. I use a 7.5V SMPS to provide clean 5V power to the USB input of a DDC (Schiit Eitr). I inserted a small, LT3045 based, 5V regulator board (ldovr.com) in the output power cable of the SMPS at about 4 inches from the end. Do you think a ferrite bead should be placed before, or after the regulator board? Thanks.

Prescription over such a long distance -- I am honestly not sure.   Here is a long distance solution, without directly looking at or understanding the 'patient': -)., since more worried about noise getting to your audio circuitry, I'd do the ferrite between the regulator and the audio.  A ferrite is a last ditch type thing, where grounding (ground planes, keeping everything equal potential) and sheilding are the first lines of defense.   But, the regulator is not likely upset by a bit of switching noise, but your audio is -- so for a first guess,  I'd probably put the ferrite closer to the audio.  Also, the pure contemporary audio circuitry and ferrite are very likely to have zero possible interaction.

 

John

 

[Superdad]

1 hour ago, Abtr said:

Hi John. I use a 7.5V SMPS to provide clean 5V power to the USB input of a DDC (Schiit Eitr). I inserted a small, LT3045 based, 5V regulator board (ldovr.com) in the output power cable of the SMPS at about 4 inches from the end.

 

The problem I see there is that you are introducing copious amounts of leakage (common-mode AC traveling over DC connections) from use of an SMPS--and that's going tight into the USB input of your Schiit device.

 

And for anyone who does not think is an issue, look no further than the clever folks at Schiit:

For any of their products which run from an external supply, they put the rectifying diodes and regulators inside the component--and include an external 6V AC transformer wart instead of an AC>DC SMPS.

Unlike with an SMPS--where 'Y' capacitors right across from primary to secondary are required--the only coupling capacitance of Schiit's small transformer is whatever small amount passes on the windings.

[sandyk]

1 hour ago, Superdad said:

 

The problem I see there is that you are introducing copious amounts of leakage (common-mode AC traveling over DC connections) from use of an SMPS--and that's going tight into the USB input of your Schiit device.

 

And for anyone who does not think is an issue, look no further than the clever folks at Schiit:

For any of their products which run from an external supply, they put the rectifying diodes and regulators inside the component--and include an external 6V AC transformer wart instead of an AC>DC SMPS.

Unlike with an SMPS--where 'Y' capacitors right across from primary to secondary are required--the only coupling capacitance of Schiit's small transformer is whatever small amount passes on the windings.

 It is possible in many cases to improve performance by earthing the 0 volts side of an SMPS supply, but where there is a power amplifier used which uses an IEC 3 pin mains socket with the chassis earthed, it may be better to use a 10 ohm (or thereabouts) resistor to mains earth instead, as it may result in a minor Earth loop. Doing this instead with my STB resulted in a small but worthwhile improvement via Coax SPDIF Out over a direct  earth.

[John Dyson]

7 hours ago, Superdad said:

 

The problem I see there is that you are introducing copious amounts of leakage (common-mode AC traveling over DC connections) from use of an SMPS--and that's going tight into the USB input of your Schiit device.

 

And for anyone who does not think is an issue, look no further than the clever folks at Schiit:

For any of their products which run from an external supply, they put the rectifying diodes and regulators inside the component--and include an external 6V AC transformer wart instead of an AC>DC SMPS.

Unlike with an SMPS--where 'Y' capacitors right across from primary to secondary are required--the only coupling capacitance of Schiit's small transformer is whatever small amount passes on the windings.

Depending on power levels, the external transformer has certain safety aspects also.  On equipment where power levels are low enough, in the old days, we'd choose transformers that are a safety barrier (before wall warts were as common as today.)  Such devices can also create a layer of isolation like suggested about the small transformer (which should probably be shielded also.)   For super high quality and safety - take a look at what medical equipment suppliers are doing, they HAVE to be expert at relatively low noise & safety.

 

John

 

[Abtr]

20 hours ago, Superdad said:

 

The problem I see there is that you are introducing copious amounts of leakage (common-mode AC traveling over DC connections) from use of an SMPS--and that's going tight into the USB input of your Schiit device.

 

And for anyone who does not think is an issue, look no further than the clever folks at Schiit:

For any of their products which run from an external supply, they put the rectifying diodes and regulators inside the component--and include an external 6V AC transformer wart instead of an AC>DC SMPS.

Unlike with an SMPS--where 'Y' capacitors right across from primary to secondary are required--the only coupling capacitance of Schiit's small transformer is whatever small amount passes on the windings.

It's just an experiment. The SMPS actually feeds 5V to Eitr's USB input as well as to a 5V coax to toslink converter. Both have their own voltage regulator. The zero volt side of the output of the SMPS is connected to Earth. In fact, it's your own (Uptone audio) 7.5V SMPS.

 

I'm planning to compare this setup to a similar setup with the SMPS replaced by a 7.5V LPS (Zero zone). And I may try your LPS-1.2.