+ Reply to Thread
Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 33

Thread: New pi stuff

  1. #11
    Join Date: Jan 2015

    Location: Leeds

    Posts: 164
    I'm Dave.

    Default

    Quote Originally Posted by sq225917 View Post
    I run a Mytek Brooklyn DAC currently. I expect this to be better in every measurable parameter, the PSU will crap on the Brooklyn, the dac chips, clocks and input options are more flexible and its not knackered by MQA.

    What dac are you currently running, anything left field?
    Don't laugh... I'm running a Pi2B and IQAudio DAC+.
    I bought it after reading Marco's "Analogue Dinosaur" thread and was shocked how good it was. Prior to that nothing had beaten my old TDA1541 based CDPs, including Auralic Vega, Benchmark DAC2, Audiolab MDAC and a few others.
    The Pi/IQ combo is very sensitive to its PS and I tried quite a few types and configurations. Oddly enough (digital lottery!) I prefer the IQ powered by the (supposedly nasty) 5v to 3V3 switcher on the Pi to being separatley powered by a fancy linear PS. I had to overcome some expectation bias durring that listening test!
    I bought a KALI & Piano2.1 set and seem to be the only person who thinks they sound poor, except for one guy on Allo's website reviews who gave he combo 1*. The Allo stuff sounded very "mechanical" to me. I tried loads of power supply options and combinations, including shorting the onboard inductors. Nothing could fix the sound. On paper the Allo stuff should be much better.

    This is why I am so cautious of buying stuff unheard.

  2. #12
    Join Date: Jan 2015

    Location: Leeds

    Posts: 164
    I'm Dave.

    Default

    Simon, you might be interested in my battery tests:
    https://www.diyaudio.com/forums/powe...ml#post5645442

  3. #13
    Join Date: Mar 2010

    Location: Sheffield

    Posts: 2,898
    I'm Simon.

    Default

    I'd seen them.

    I have an lt1083 feeding a quad of parallel lt3045 into my Brooklyn, it sounds a little bit better than the internal smps. A triplet of non protected 18650, Samsung 3400mAh sounds quite a bit better. So I have no worries about Ian's supply, even if he is lacking his usual measured follow through.

    When you say quite fancy linear psu did you buy it in or build it? I tried a couple well regarded Chinese linear psu, they were crap way off spec for noise. Very disappointing.

    The lodvr dx power should also be very good, state of the art numbers.
    Kuzma Stabi/S 12", (LP12-bastard) DC motor and optical tacho psu, Benz LP, Paradise (phonostage). MB-Pro, Brooklyn dac and psu, Bruno Putzeys balanced pre, mod86p dual mono amps, Yamaha NS1000m

  4. #14
    Join Date: Jan 2015

    Location: Leeds

    Posts: 164
    I'm Dave.

    Default

    Actually I shouldn't have written "fancy" it's actually quite prosaic.
    It's one of these:
    https://www.ebay.co.uk/itm/Ultra-low....c100642.m3226

    It is important NOT to use a toroidal transformer to power it. I use a 30VA split bobbin type.
    Use full wave centre-tap recification - which needs two of the diodes to be removed and use of the 0V connection.
    I don't use C-RC snubbing (actually i went through my entire system adding these and it took me quite a while to figure out what caused the poorer sound).

    I have also tried a few standard regs, a Coffin superreg (with AD825) and an MRAVICA TPS7A4700 regulator.

  5. #15
    Join Date: Mar 2010

    Location: Sheffield

    Posts: 2,898
    I'm Simon.

    Default

    How had you calculated and applied your C-RC snubbers? Quasimodo style?
    Kuzma Stabi/S 12", (LP12-bastard) DC motor and optical tacho psu, Benz LP, Paradise (phonostage). MB-Pro, Brooklyn dac and psu, Bruno Putzeys balanced pre, mod86p dual mono amps, Yamaha NS1000m

  6. #16
    Join Date: Jan 2015

    Location: Leeds

    Posts: 164
    I'm Dave.

    Default

    Yes.
    Once again, expectation bias got the better of me for a while. That lovely critically damped waveform provides lots of peace of mind!

    I wonder if the C-RC snubber has some downsides when the transformer is "terminated" with a rectifer and smoothing caps - which is rather different to the way the transformer is tested in isolation.

  7. #17
    Join Date: Mar 2010

    Location: Sheffield

    Posts: 2,898
    I'm Simon.

    Default

    I test mine in situ, just without voltage going through the traffo. But maybe you're onto something.

    That said I've never heard a downside but then again they are before a CLCRC with 10,000uf caps, a 1H choke and a 10r resistor. it's all pretty smooth out the back of that.
    Kuzma Stabi/S 12", (LP12-bastard) DC motor and optical tacho psu, Benz LP, Paradise (phonostage). MB-Pro, Brooklyn dac and psu, Bruno Putzeys balanced pre, mod86p dual mono amps, Yamaha NS1000m

  8. #18
    Join Date: Jan 2015

    Location: Leeds

    Posts: 164
    I'm Dave.

    Default

    Back on topic... at least the snubbers are irrelevant for the LiFePO4 supplies.
    It looks like they are much lower ESR than my cycling batteries and as long as they are <10mOhms or so, should be fine. I ought to buy a couple and test them.

  9. #19
    Bigman80 Guest

    Default

    This thread had litle meaning to me a few weeks back but now i am reading with interest.

    I have been speaking to Ian about his Isolator board. It will fit my Pi3+ and Allo dac but i dont understand how to power it? It doesn't have the Micro USB port so how would it be done?

    The PSU i will be using is this:

    https://www.ebay.co.uk/itm/25VA-Ultr...72.m2749.l2649

    Any help is appreciated.

  10. #20
    Join Date: Mar 2010

    Location: Sheffield

    Posts: 2,898
    I'm Simon.

    Default

    See that green connector, thats dc in.
    Kuzma Stabi/S 12", (LP12-bastard) DC motor and optical tacho psu, Benz LP, Paradise (phonostage). MB-Pro, Brooklyn dac and psu, Bruno Putzeys balanced pre, mod86p dual mono amps, Yamaha NS1000m

+ Reply to Thread
Page 2 of 4 FirstFirst 1234 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •