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  1. #1

    Power supply again: switching vs. linear

    Hi all,

    do we really have to choose between the two alternatives
    poor switching PSU / good linear PSU?
    Isn't there any high quality switching power supply?
    For the switching PSU has its benefits: smaller, less heat, more efficient.

    Any educated guess?

  2. #2
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    It depends?

    Linn and a few other companies use switching psu, Linn are raving about their new Dynamic. so it depends on the quality of the power unit itself and if you are using a seperate dac then it will be less affected. Then again some Dacs use switching psu also.
    I personally feel that anything that gets hot will have temperature dependant effects on the output.

  3. #3
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    what it must not do is allow noise on the mains or noise it creates itself to be injected onto the power rails ...

    thats regardless of psu type

    its far easier to build a quiet linear than a switch mode at sensible prices ...imo
    Acoustician and builder of interesting cables

  4. #4
    Senior Member iPhone's Avatar
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    Power Supplies in General

    Sure a well engineered isolated Linear Power Supply is the PS of choice if somebody is building something and deciding on a PS. Having said that, we aren't really talking about designing a device or circuit but about replacing an OEM supply.

    The Squeezebox has internal switching supplies inside it so changing to a Linear PS really has no benefit over a stock OEM switching power supply because it will still be feeding internal switchers. Two reasons to replace the OEM Squeezebox PS: original PS has died, one has a ground loop noise that replacing the PS solves the issue.

    Phil and I have both tested changing the power supply and there are no differences. Save your money and move up to a Touch or Transporter if ones current Squeezebox is not high end enough. I have even tested using battery supplies with no difference and gone as far as bypassing the internal switchers with no heard differences and only the slightest measurable difference/improvement. IE, not enough difference to go to all the expense and trouble to modify and bypass all the internal switching supplies.
    iPhone
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    Living Room:
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  5. #5
    Senior Member Phil Leigh's Avatar
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    Wink

    Quote Originally Posted by iPhone View Post
    Sure a well engineered isolated Linear Power Supply is the PS of choice if somebody is building something and deciding on a PS. Having said that, we aren't really talking about designing a device or circuit but about replacing an OEM supply.

    The Squeezebox has internal switching supplies inside it so changing to a Linear PS really has no benefit over a stock OEM switching power supply because it will still be feeding internal switchers. Two reasons to replace the OEM Squeezebox PS: original PS has died, one has a ground loop noise that replacing the PS solves the issue.

    Phil and I have both tested changing the power supply and there are no differences. Save your money and move up to a Touch or Transporter if ones current Squeezebox is not high end enough. I have even tested using battery supplies with no difference and gone as far as bypassing the internal switchers with no heard differences and only the slightest measurable difference/improvement. IE, not enough difference to go to all the expense and trouble to modify and bypass all the internal switching supplies.
    +1 from me. If I thought that a few hundred pounds on a power supply would revolutionise my listening experience I would spring for it... but the tests show otherwise. Of course. you don't HAVE to believe the tests...
    You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal...
    Touch(wired/W7)+Teddy Pardo PSU - Audiolense 3.3/2.0+INGUZ DRC - MF M1 DAC - Linn 5103 - full Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters,VdH Toslink,Kimber 8TC Speaker & Chord Signature Plus Interconnect cables
    Stax4070+SRM7/II phones
    Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything.

  6. #6

    Thumbs up

    Thanks for setting me straight!

    Thomas

  7. #7
    Senior Member Greg Erskine's Avatar
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    Quote Originally Posted by thomasfoerster View Post
    Thanks for setting me straight!

    Thomas
    This is the DIY section, try it yourself and come to your own conclusions. Don't every take anyone's opinion as fact.

    regards

  8. #8
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    For me there was a major reason for going with a linear supply for my SB3, the little switcher that comes with it radiates all kinds of junk, out of the box and out from the wire to the SB3. My system at least was fairly susceptible to that junk. Going to a good linear cleaned all that up.

    I agree with the others that there is not a significant improvement in the signal coming out of the SB3, but getting rid of the switcher that came with the SB3 was big improvement in my system.

    John S.

  9. #9
    Senior Member iPhone's Avatar
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    Documented Fact, not opinion

    Quote Originally Posted by Greg Erskine View Post
    This is the DIY section, try it yourself and come to your own conclusions. Don't every take anyone's opinion as fact.

    regards
    If you are referring to my post, it is not opinion it is documented, measured, and proven fact. I was not stating an opinion, I was stating documented facts. I also have good ears when it comes to HiFi and heard no difference.

    There is no improvement whatsoever from changing out the OEM PS for any linear PS when it comes to the SB3 or Receiver.

    And anybody that says they can hear a difference is letting their emotions and brains fool their ears. The program that Phil and I have been using back this up as well as a calibration certified HP Network Analyzer and Measuring Receiver. The output recorded wave forms ARE identical using both power supplies. So it is impossible for anybody to suddenly hear better sound or deeper this or that from just replacing the OEM switching PS with another power supply, even a battery source.

    And as I stated, there are two reasons to replace the OEM supply. Ones original PS is dead or there is an issue with ones system with a ground loop or noise from the switching supply. If these two items are not an issue, nothing is to be gained from replacing ones OEM supply, period.

    This is the DIY section and I have taken a Receiver all the way down so that each voltage requirement received its own battery supplied voltage. About as pure as it gets. The recorded output waveform was slightly different reflecting a slight improvement in audio quality. I didn't hear this improvement but it was on the graph. IE not worth the time, trouble, and expense of going to all the trouble for so small an improvement that ends up not even being able to be heard. The reason I did it was I had the time and wanted to see for myself. And it also proved that if going to that extreme was no difference, no way changing to just a Linear PS was going to make any difference.

    Documented and proved many times over by multiple methods that there is nothing to be gained from replacing the OEM PS unless the two above problems already exist.

    If it makes somebody feel better about their music to spend 2/3 the cost of a Squeezebox on a new linear PS then that might have some value to that person, but their Squeezebox plays and sounds the same as mine with the OEM PS.
    iPhone
    Media Room:
    ModWright Platinum Signature Transporter, VTL TL-6.5 Signature Pre-Amp, Ayre MX-R Mono's, VeraStarr 6.4SE 6-channel Amp, Vandersteen Speakers: Quatro Wood Mains, VCC-5 Reference Center, four VSM-1 Signatures, Video: Runco RS 900 CineWide AutoScope 2.35:1, Vandersteen V2W Subwoofer

    Living Room:
    Transporter, ADCOM GTP-870HD, Cinepro 3K6SE III Gold, Vandersteen Model 3A Signature, Two 2Wq subs, VCC-2, Two VSM-1

    Office: Touch with Vandersteen VSM-1s
    Kitchen: Touch in-wall mount w/ Thiel Powerpoint 1.2s
    Bedroom: Squeezebox BOOM
    Bathroom: Squeezebox Radio
    Around the House: SliMP3, SB1, SB2, SB3
    Ford Thunderbird: SB Touch, USB drive
    Ford Expedition: SB Touch, USB drive

  10. #10
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    Quote Originally Posted by iPhone View Post
    If you are referring to my post, it is not opinion it is documented, measured, and proven fact. I was not stating an opinion, I was stating documented facts. I also have good ears when it comes to HiFi and heard no difference.

    There is no improvement whatsoever from changing out the OEM PS for any linear PS when it comes to the SB3 or Receiver.

    And anybody that says they can hear a difference is letting their emotions and brains fool their ears. The program that Phil and I have been using back this up as well as a calibration certified HP Network Analyzer and Measuring Receiver. The output recorded wave forms ARE identical using both power supplies. So it is impossible for anybody to suddenly hear better sound or deeper this or that from just replacing the OEM switching PS with another power supply, even a battery source.
    As they say, people who speak in absolutes are always wrong.

    You have not established that there is "no improvement whatsoever" to be had from improving the power supply. You have, however, established an upper bound on the improvement that might possibly be obtained. This upper bound is determined by the quality and suitability of your test equipment and configuration.

    Could you kindly discuss the noise floor and noise spectrum you measured with the two power supplies?

    (In other words, "put up or shut up". )

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