linear or switch mode?

[Pieoftheday]

hi all, ive got a muse none oversampling dac on the way,it does come with a power supply but if its anything like the last supplied one ill want something better, or at least one that dosnt look dangerous! so , linear vs switch mode? or dosnt it matter ? thanks jim

[Oldpinkman]

Ha!
I am slightly less ignorant as the result of some recent tests , experiences and discussions. The short answer is linear. Providing it really is linear, and doesn't just say that in the pigeon-chinese marketing blurb. It is easier to get a low noise power supply using a linear design, and so most common linear supplies are likely to be quieter than smps. But a well designed basic SMPS with regulation is going to be quiet enough in most applications.
However, done properly, SMPS can be as quiet as batteries. Its just that its a bit involved and ideally needs integration with the device in question. Rather than wait for the "b****cks" response, take a look at the latest Benchmark AHB2 amplifier, which uses an SMPS with THD plus noise better than -108db at full output.

[Welder]

Ha!
Rather than wait for the "b****cks" response, take a look at the latest Benchmark AHB2 amplifier, which uses an SMPS with THD plus noise better than -108db at full output.

Interesting isn't it. :)

[Oldpinkman]

Interesting isn't it. :)

It is. It's also the cause of the sluggish response from the Quad 405-2 and Pip repair department! :rolleyes: Impressive achievement. 130db dynamic range, and runs cool. Not heard one yet, but I doubt its shoddy...:cool:

[Arkless Electronics]

Agreed up to the bit that starts "However, done properly, SMPS can be as quiet as batteries." This needs qualifying! For a start batteries are not the quietest power source available The ultimate arbiter of overall PSU quality, taking things to the n'th degree, is the voltage regulator/s and the grounding layout (assuming there are voltage regulators in use!). Provided that sufficient smoothing and filtration is used ahead of the voltage regulators (VR) then it shouldn't really matter where the power to feed the VR comes from. The very best VR's are quieter than even batteries.... and for best results should be fitted inside the unit being powered rather than inside an external PSU box.
If a linear PSU is unregulated then the 100Hz (and sometimes 50Hz) noise can be (and often is) at a much higher level than the (usually!) ultrasonic noise from a SMPSU! Much depends on the degree of smoothing and filtering in either unit. Ultimately a SMPSU will usually be noisier as the radiated interference will often be higher and the nature of the HF noise from an SMPSU can make it difficult to filter as effectively as the LF noise from a linear supply.

So... yes usually the best is a regulated linear PSU but be be sure to be comparing apples with apples and remember it's horses for horsd'oeuvres.. I mean courses ;)


Ha!
I am slightly less ignorant as the result of some recent tests , experiences and discussions. The short answer is linear. Providing it really is linear, and doesn't just say that in the pigeon-chinese marketing blurb. It is easier to get a low noise power supply using a linear design, and so most common linear supplies are likely to be quieter than smps. But a well designed basic SMPS with regulation is going to be quiet enough in most applications.
However, done properly, SMPS can be as quiet as batteries. Its just that its a bit involved and ideally needs integration with the device in question. Rather than wait for the "b****cks" response, take a look at the latest Benchmark AHB2 amplifier, which uses an SMPS with THD plus noise better than -108db at full output.

[Oldpinkman]

I knew you'd know Jez. And I knew I have much more to learn. But I did shed a few layers of ignorance this weekend. I added a big dollop of capacitor for Alan, and made the mistake whilst discussing this with Mr J of observing that the Pip power supply seemed pretty basic in that regard. He drew a picture to explain how wrong I was! And then went on to discuss the AHB2. But as you noted, for all the loose talk, the basic point is probably true.

[bobbasrah]

There is a fair amount of hogwash spouted over SMPS, there are a lot of very well designed ones around, and a lot of circuits designed which don't care unless you feed them absolute crap on the PSU.
Suggest you trawl the forums such as diyaudio James, the Muse units etc are frequently tinkered with which will point you toward optimum solutions, even if a bit of DIY is required...

[Pieoftheday]

There is a fair amount of hogwash spouted over SMPS, there are a lot of very well designed ones around, and a lot of circuits designed which don't care unless you feed them absolute crap on the PSU.
Suggest you trawl the forums such as diyaudio James, the Muse units etc are frequently tinkered with which will point you toward optimum solutions, even if a bit of DIY is required...

Blimey !!well il see what comes with at first , dosnt look like id have to spend too much either way, thanks all