Best way to get audio from iMac to Amplifier

Discussion in 'iMac' started by Vazzyb, Aug 23, 2011.

  1. Vazzyb macrumors member


    Mar 18, 2009
    Cambridge, UK.

    I wanted to know what the best way to get audio from my 2011 iMac to an external integrated amplifier was. The amplifier has both digital (optical) and analogue (phono) inputs; its a Rotel RA 1520.

    My primary concern was that I wanted to keep the quality of the sound as high as possible. The rest of the system was designed with quality in mind. Therefore using a stereo jack to phono adapter is probably not a good idea.

    Are there digital alternatives? eg. using an external sound card with an optical output?

    Its not just music that I want to send to amp, its also the sound from movies. For music, I think I could use a Sonos.

    Thanks very much

  2. Vazzyb thread starter macrumors member


    Mar 18, 2009
    Cambridge, UK.
  3. thebignewt, Aug 23, 2011
    Last edited: Aug 23, 2011

    thebignewt macrumors regular

    Jun 10, 2011
    I don't think there's an easy wired connection. I use an Airport Express and a simple RCA wire to connect it to my receiver for my home stereo (pretty good Klipsch speakers). The only ouput connections for that unit is 3.5mm headphone jack, and a USB for a printer). That only plays iTunes music library, I control that with my iPod touch and the free Remote app. I also bought an Apple TV (they are both about $100). I connect that using an optical audio wire to my surround sound amp that's with my HDTV and speakers (Paradigms). It also has an HDMI output. That will also play my iTunes music library (as well as video). An apple remote comes with that unit and the menus are on the TV of course. I you are bent on optical wire then you'll have to use your TV to make selections. I suspect both ways will sound good, at least they do for me.
  4. aliensporebomb macrumors 68000


    Jun 19, 2005
    Minneapolis, MN, USA, Urth
    Why not

    Why not use an optical cable from the audio out to the SPDIF in on the Rotel? It's a mini SPDIF cable on the iMac end and depending on what your Rotel has you might go mini or full side SPDIF. I've been using the digital inputs on my iMac from a digital audio mixer (full size SPDIF out) and it works well. They are digital in/outs on the iMac machines.

    Interesting that you have a Rotel amplifier - I do too but it's about twenty years old and still works great. No digital I/O there so not quite sure what I would use.
  5. 88 King macrumors 6502

    88 King

    Jun 18, 2011
    London, UK
    The imac have optical out through the headphone jack.

    The cheapest solution is to get 3.5mm headphone jack to optical converter.

    If you want to spend money on external sound card, I think it’s better to get a digital audio converter (DAC). I’m using DacMagic by Cambridge Audio, it produces very good sound for reasonable price.
  6. zarathu macrumors regular


    May 14, 2003
    I'd use the headphone jack into the tape or the cd input. I don't know what other choice you have. Of course if all you are transferring is mp3's it may not make that big a difference. Sampling rate on mp3's is not that super.

    What kind of audio are you transferring out.
  7. Roy G Biv macrumors 6502

    Roy G Biv

    Dec 26, 2010
  8. MaloCS, Aug 23, 2011
    Last edited: Aug 23, 2011

    MaloCS macrumors regular

    Aug 11, 2011
    I just did what you are trying to accomplish.

    You'll need the following:
    1. Belkin Toslink cable with 3.5mm adapter Link to Belkin Cable >>
    2. A stereo/tuner/receiver with optical input or...
    3. An external DAC (Digital Audio Converter) with optical input and RCA outputs. Link to External DAC >>

    The first thing you'll want to do is set the audio output jack on the rear of the iMac to digital output via the audio preferences.

    Then you connect the 3.5mm adapter to one end of the Belkin cable and insert it into the audio output jack on the rear of the iMac.

    Finally, you plug the other end of the Belkin cable into an optical input in either your receiver or external DAC. If you choose to use an external DAC you will need a set of RCA stereo cables to get the audio signal from the DAC to the receiver. It looks like your receiver has an optical input so you do not need an external DAC. The only reason to use an external DAC in your situation would be to bypass your receiver's on board DAC if you were unhappy with it. In my particular case I'm using a receiver from the early 1970s so an external DAC is a necessity.

    One thing to take note of is that once the audio output is set to digital the iMac locks the volume to 100% and prevents the user from adjusting it. I'm assuming that Apple locked the volume to 100% because the receiver will now control the volume.

    Keep in mind that you may find similar/comparable products online for much less money. The links I provided are just to give you an idea of what type of equipment you need to in order to obtain the best quality sound out of your stock iMac. Of course, you can always choose to install a professional grade external sound card but I don't feel that's necessary for audiophile stereo playback.

    Some people claim that internal computer noise can seep into the on board audio circuitry and degrade the signal but in several years of using my computer as an audiophile listening source I haven't noticed it. Your ears may be more sensitive then mine but I would give the above setup a try before dropping the coin on an expensive external audio card.
  9. aliensporebomb macrumors 68000


    Jun 19, 2005
    Minneapolis, MN, USA, Urth

    For what it's worth I've professionally produced at least a dozen commercially released compact discs using Macintosh internal audio circuitry.

    Nobody has ever complained about the audio not sounding "clean" enough that I've been aware of.

    Most folks are stupefied it was recorded on a Mac in a small studio/office.
  10. wkw macrumors 6502


    Mar 23, 2004
    Eugene, OR
  11. Alinoe macrumors newbie

    Aug 25, 2011
    Your iMac has an optical out port. If your amp has an optical in port, why bother with a DAC (unless you're a serious audiophile)? Just get a cable.
  12. jrichman63 macrumors regular

    Sep 4, 2006
    Pacifica, CA
    Apogee duet or apogee duet 2

    Or presonus audio interface
  13. Fishrrman macrumors G5


    Feb 20, 2009
    "I wanted to know what the best way to get audio from my 2011 iMac to an external integrated amplifier was. The amplifier has both digital (optical) and analogue (phono) inputs; its a Rotel RA 1520."

    I went to the Rotel page and looked at the manual (which has a diagram of the back), and I didn't see any "optical input". Are you _sure_ it has a digital input?

    Do you know what kind of input connector is on the amplifier?
    Do you know what _type_ of digital input format the amplifier can support?

    IF the input is digital/optical, you should be able to use a simple TOSLINK digital/optical cable to make the connection.

    You MAY need small "adapters" on either end of the cable. Most TOSLINK cables come with a "rectangular" type of plug that looks like this:

    You can get a small adapter for the iMac end that looks like this:

    Here's the same kind of adapter with an "L-shaped" end that swivels (very handy):

    Here's an "extension coupler" that lets you hook 2 cables together end-to-end:

    Whether you will need the same adapter on the "amplifier end" depends on what kind of connection port it has.

    IMPORTANT: if the amplifier has a "phono type" SPDIF input (looks like an "RCA" phono plug), you may need some kind of "converter" to go between them. The converter doesn't change the signal from digital to analog, but instead "converts the format" between connectors.

    There is a length limitation, however. The following info is snipped from widipedia:
    "TOSLINK cables are usually limited to 5 meters in length, with a technical maximum[1] of 10 meters, for reliable transmission without the use of a signal booster. However, it is very common for interfaces on newer consumer electronics (satellite receivers and PCs with optical outputs) to easily run over 30 meters on even low-cost ($0.75/m) TOSLINK cables. TOSLINK transmitters operate at a nominal optical wavelength of 650nm(~461.2 THz)."

    Again, after a quick review of the manual for the above amplifier, I didn't see any "digital input".

    If that's the case, you could still get music out of the iMac and into the amplifier by using a USB/DAC converter box. There are many of them available:
  14. 911scanner macrumors member

    Jan 31, 2011
    I too was having this issue when I first purchased my iMac 11,3. I wanted to use my truly digital integrated amp (that I already owned) with some decent bookshelf speakers.

    In my quest, I used a digital out cable from the headphone jack for awhile. I liked this method, except for needing better speakers and the lack of volume control integrated into the Mac.

    Then I started considering amplified bookshelf speakers. I stumbled on the AudioPro LV2 speakers and have been happy as a clam ever since.

    Not an inexpensive option, but you will be amazed when you hear them.


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