Desktop Amp: USB or Optical?

Discussion in 'Digital Audio' started by fiatlux, Oct 25, 2012.

  1. fiatlux macrumors regular

    Dec 5, 2007
    I just started playing piano and gained interest in digital audio. My Mac Pro having been used mostly for digital photography so far, it only had fairly basic speakers attached (LaCie USB speakers designed by Neil Poulton).

    I was thinking about investiing in a small desktop amp (NuForce Icon 2, project, ... SMSL) together with a pair of good monitor or dipole surround speakers.

    Many such amps offer a USB connection, but I noticed that my current USB speakers often suffer from spurious emissions.

    Is this a Mac USB audio issue? Would a DAC connected to the digital output of the Mac Pro sound better?
  2. spoonie1972 macrumors 6502a

    Aug 17, 2012
    A studio DAC (or even pro-sumer, or things marketed to audiophiles) will most certainly have its own character - but the big questions is - will you be able to tell the difference?

    If your planned source is FLAC, and you have high-end speakers, and, just as importantly - a well treated room, it may be worth while.

    If you're listening to 320kb mp3's, it might not be worth the investment.

    As for USB amps having spurious output issues.. do they convert and draw power from the USB port for the amplification? That seems.. unwise - if that's the case.

    If you do use a USB converter, probably best to have only that device using that bus, especially if you're planning on playing stereo channels out above 48k.

    Best luck whatever your goals are.
  3. Destroysall macrumors 65816

    Feb 28, 2012
    United States
    What do you want to do, listen through speakers or headphones? Or do you want the best of both worlds? What's your budget?
  4. jazz1 macrumors 65816


    Aug 19, 2002
    Mid-West USA
  5. ScottishCaptain macrumors 6502a

    Oct 4, 2008
    Do yourself a favour and forget about the traditional amp/speaker combo.

    What you want is a studio grade setup. This means that the ADDA (analogue -> digital, digital -> analogue) converter is separate from the amplifier, which is typically housed in the speaker itself. The ADDA takes in USB (or firewire) and spits out a pair of balanced XLR outputs, which then run into your speakers. Since the speakers are self-powered, you don't need to worry about USB power draw because the only thing you're powering is the ADDA converter.

    I would recommend something like the Apogee Duet 2 for an ADDA converter, along with a pair of ADAM A3X speakers. The Apogee DACs are borderline unparalleled (except by uber high-end gear like the Prism Orpheus), they're the same DACs Apogee uses in the Symphony I/O.

    The ADAM Speakers are unparalleled in quality because of the AMT tweeters they're using (you won't really find anything like that on another speaker these days). They're self powered and run off balanced XLR (balanced XLR means the cable is immune to electrical interference), and they're impossible to overload or burn out since the amplifiers built into them protect against that kind of thing.

    In total such a setup will probably run you at around $1200 ($529 for the Duet 2, $349/speaker). Trust me on this one, your money is far better spent on studio gear then anything that is "audiophile" grade. $1200 for a stellar ADDA converter and two ADAM speakers is hard to beat in terms of quality.

  6. ChrisA, Oct 26, 2012
    Last edited: Oct 26, 2012

    ChrisA macrumors G4

    Jan 5, 2006
    Redondo Beach, California
    The big question you are asking is where to put the DAC. There is one inside the computer that drives you line-out/headphone jack. Then you can buy an audio interface with a DAC inside and as you say conect it with either optical or USB.

    My opinion. If you are musician with a digital piano you might like to use it as a MIDI controller or record your playing. So buy an audio interface that is designed for use in a small recording studio.

    I like this one it has a built-in MIDI interface and will do 96K x 24-bit audio in both directions and has 48 volt phantom power for mics if you need that. and the price is not bad. It has balanced outputs so you can drive studio monitors that typically have balanced inputs.
    The top video is really good, watch it to the end and read the titles.

    SOme people like the Apogee Duet. It has some big faults and one advantage. The faults are tthat it uses a dogle (octopus) for cable connections, it has only ONE knob that is multi-fictions, the sound quality on playback is no better then units 1/2 it's price. The one good feature is low noise recording. the INPUT section is good. However the input section on the "audio box" is good too. ANd then you you own any $900 microphones? If not you want notice as the mics are the weak link.

    All that said, none of this matters so much. What REALLY matters in other of importance, most importance first is

    1) room acoustics and any acoustical treatments you have done
    2) placement of the speakers relative to both the walls and you.
    3) the brand and model of speaker
    4) the electronics (audio interfaces, amplifiers, cables and what not) you use to drive the speakers

    Think the entire system through, especially if you will be doing any music production/recording using your piano.
  7. fiatlux thread starter macrumors regular

    Dec 5, 2007
    Thank you for your suggestions!

    I would like to clarify my needs/wishes. It is not so much to listen to music than having a better sound when playing software piano on my Mac.

    My current piano keyboard is connected in midi over USB an that seems to work well. I see no need to go the old midi connectors way.

    My current speakers draw power and audio from USB. I don't know wheter that's a problem but connecting them directly to the machine (as opposed as a powered hub) did not change anything - i stll have the occasional sound glitch.

    I had a look at powered monitors as well, and would be interested in why this woul necessarily be a better solution than separate amps and passive speakers.

    Finally, I would like to clarify that I'm not really trying to set up a home studio. My Mac will have to stay where it currently is (mezzanine over my living room), which means that sound proofing the room will not be an option and I'll have to live with reverb. Not such a bad thing for piano, i'd guess...

Share This Page