My setup is Computer>UPnP via 10G spec optical Ethernet>Streaming Device>Optical USB Cable (no copper thru connection)>DAC. DAC power and power injection to the DAC end of the USB cable are from LPSs.
Acting on a recommendation from another forum, I substituted an inexpensive ($30 US) medical grade power supply from the company CUI for the power supply that originally came with the streaming device. Because it is medical grade, though it’s a switching power supply (as was the original power supply), it complies with a spec that provides for very low leakage current.
I feel subjectively this has resulted in a small improvement in sound. Of course any such subjective impression must be taken with due skepticism.
When I replaced the power supply that came with the DAC IFi Neo iDSD 2 with the iFi IPower Elite 12V, there was a good improvement.
But as you wrote, these are subjective impressions.
I also use an Ifi Power Elite on my Fanless PC and it is a good update, you can Say subjective if you want… But in fact that IS not why dogmatics people do not want to accept the influence of power supply that it is subjective
Since I haven’t measured anything, it’s of course necessarily subjective. I don’t want to steer people wrong, so while I’m happy to talk about a very inexpensive power supply that may be helpful, I also want to be sure to mention I can’t give any assurance beyond a listening impression.
Certainly it’s objectively true that we’d like to reduce system noise. Whether and to what extent this particular supply may do so beyond the one that comes with the Fitlet3 would have to be the subject of measurement.
Regarding switching mode power supplies, here’s a quote from a manufacturer in another forum, and the reason I emphasized this is a medical grade supply with very low specified leakage current:
"However, the real evil of an SMPS are the leakage currents (common-mode AC pumped onto its DC output) which are primarily a byproduct of the required ‘Y’ capacitor that sits directly across the transformer windings of every SMPS. These leakage currents are also broadband—from 1KHz up to many megaHertz—very spiky, and sometimes fairly high in level. And they perniciously form loops between networking and audio gear—and the leakage from multiple components (connected via any digital, power, or analog cable grounds) interact with each other.
“This is the true primary cause of sonic disillusionment with the use of SMPS.”
Not possible to trade - 5v vs. 12v. At less than a tenth the cost of an LPS and with a low leakage current spec, I’m happy with the SMPS in this application.
Absolutely perceived sound quality will always have a very large subjective element. I like to try to do as well as possible with the objective elements that can be controlled, like noise and jitter. Luckily, whatever little I’ve been able to do in that direction has resulted in a system through which I really enjoy listening to music.
Yep, I do know that, though it’s also considerably more expensive than the $30 CUI. If I’ve seen leakage current measurements or specs for the Elite I don’t recall them. Anyone else know?
The heart of the problem is the scale of the leakage capacitance, which can be in the range of hundreds of pF for larger system power supplies. An elegant solution is to use a separate isolated DC-DC converter with extra-low coupling capacitance powered from a system voltage. This approach provides the relatively small power requirements of the sensitive analog audio stage. An isolated DC-DC converter with a typical coupling capacitance of 10 pF or less can keep common mode current to a very low level. The original intended application for such converters is to power gate drivers, where the low capacitance gives immunity to the high dV/dt levels in high-side drives. Alternatively, many smaller regulated and unregulated isolated DC-DC converters could potentially be used, with their coupling capacitance significantly lower than what is seen in larger AC-DC supplies.
…And they perniciously form loops between networking and audio gear—and the leakage from multiple components (connected via any digital, power, or analog cable grounds) interact with each other.
