HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

I was prompted by a comment of Fretless's relating to the potential to improve the performance of a DAC I had my eye on by adding a Linear Power Supply, to investigate the subject further. Needless to say this prompted some googling and 'research', in the hope of obtaining some sort of enlightenment on the benefits. Predictably (I suppose), what I found was no consensus and a deal of contradictory information and opinions, the general message being that the design concept (my phrase) was perhaps less important than how it was implemented. So - how does the HiFi Subjectivist hive mind feel about the merits of each? And, is there a reasonably priced PSU of either type that anyone feels inclined to recommend that would improve the performance of the stock one for a CA Dacmagic Plus? Thanks.

There is no right answer. However, if you use a linear power supply from a reputable vendor then you are more likely to get a satisfactory result.

Suck it and see?

I use an SBooster PSU for my DacMagic DAC, which is fairly expensive. Tomanek in Poland make good LPSU's and from AliExpress I have a Weiliang Audio power supply, which is also fine and pretty cheap.

Switched-mode PSU's do NOT work well with BMU's.

I use Sboosters for the DAC, Mscaler and streamer in the main system. They provided a considerable improvement in SQ, particularly the bass. They were worth the extra expense over the two MCRUs I was using which are now in the second system.

I don't think the importance of PSs for digital source components can be underestimated, as with amplifiers.

I had a bad experience with the standard switch mode supply of a Project CD player.
All was fine until I replaced my phono stage with a Parasound unit (which incidentally has an inbuilt linear supply). As soon as I used the phono stage I encountered noise similar to that from unshielded phono cables. This stopped as soon as I disconnected the power lead from the CD player. Speaking to Analogue Seductions, who supplied the Parasound, it is not uncommon for problems like this with switch mode power supplies which are often built/designed down to a price. Rather than the expense of a linear power supply I found earthing the CD player case solved the problem.
So, yes switch mode power supplies can cause noise.

Also consider the failure rate of SMPS vs LPSU. Transformers in linear supplies rarely go tits up. That only leaves rectifiers and smoothing capacitors. Easy to fix or service. Regulators usually stay in the main box near their load (or should do).

Most switch mode are landfill when they fail. I wouldn't know where to start trying to fix one. Although linear are much heavier and more expensive to make and ship I would say they repay (your pocket and the planet) with their longevity .

Interesting responses - thank you all. Food for thought, for sure.

Interesting indeed, another option is a battery. I found that a Poweroak K2 battery that supplies a USB 5 V DC signal to the Chord Hugo2 DAC, much better than either a switched or linear PS. The same battery will also supply 12 V or 20 V , its also rechargeable whilst supplying

Nearlymusical wrote: ↑Fri Dec 02, 2022 9:03 pm Interesting indeed, another option is a battery. I found that a Poweroak K2 battery that supplies a USB 5 V DC signal to the Chord Hugo2 DAC, much better than either a switched or linear PS. The same battery will also supply 12 V or 20 V , its also rechargeable whilst supplying

I was going to make a similar point, a high capacity battery will provide the cleanest power but, there has to be a but. But the internal resistance of a battery my inhibit its ability to deliver current quickly enough for transients when powering amplification. However for a pre-amp or DAC it would probably be ideal as transients don’t demand much current at line level.

There is also the consideration as to the type of battery. The relatively large capacity of a car battery may look attractive but they are designed to deliver high current for a short duration but as a result aren’t happy with low current over an extended period. A Lithium Ion battery might offer an attractive solution.

Probably the best arrangement for an amplifier might be a linear PSU stabilised by a suitable battery. For a source component a battery alone could provide several hours operation but… Batteries have lives measured in charge cycles, used every day for a year the life could be around 13 or 14 months. Li-ion batteries need protection circuits, especially over discharge protection, which has to be between the battery and the load. Richard wouldn’t be impressed!

There’s no one simple answer but a linear PSU, with or without battery stabilisation, is probably the best compromise.

I did use a large 5V/3A powerbank for a Pi-based streamer for a while, this was soundwise better than a switching wall-wart but not as good as an LPSU with transformer.