[AndrewFischer]

The new iMac has S/PDIF and analog stereo outputs on an single 3.5mm 'combo' jack. Pluging in a 3.5mm toslink connector selects digitial output. Plug in a 3.5mm stereo headphone connector selects analog output.

Specs from Apple's developer note:

Digital output specs:

1. Output Data Formats: S/PDIF (IEC60958-3), AC3
2. Output Sample Rates: 32KHz, 44.1KHz, 48KHz, 64KHz, 88.2KHz, 96KHz
3. Bits per Sample: 16 or 24 (S/PDIF),16 (AC3)
4. Frequency Response: 20Hz – 20KHz, +/-0dB
5. Signal-to-Noise Ratio (SNR): >130dB
6. Total Harmonic Distortion + Noise (THD+N): <-130dB (0.00003%)
7. Channel Separation: >130dB

Analog output specs:

1. Output Sample Rates: 32KHz, 44.1KHz, 48KHz, 64KHz, 88.2KHz, 96KHz
2. Bits per Sample: 16 or 24
3. Output Impedance: <50 Ohms
4. Output Level: 1.75VRMS (+7.1 dBu)
5. Frequency Response: 20Hz – 20KHz, +/-0.5dB
6. Signal-to-Noise Ratio (SNR): >90dB
7. Total Harmonic Distortion + Noise (THD+N): <-85dB (0.006%)
8. Channel Separation: >85dB
9. Output Power (Into 16 ohm Headphones): 60mW

The headphone jack is the only analog output jack. There is also an analog line-in.


Apple's published specs are of course only a starting point to determine sound quality.

 

[lan]

Onboard sound usually isn't that good and those analog out specs aren't that great.

Setting quality aside, I personally wouldn't use this as a computer source since the mac software have a lack of features compared to foobar2000 and zoomplayer.

 

[AndrewFischer]

Quote:

Originally Posted by lan Onboard sound usually isn't that good and those analog out specs aren't that great.

No they are not. They aren't dreadfull either. The output impediance is higher than I would like. The output voltage might be too low for some headphones. A good amp will help a lot here. The THD+N and SN are OK, but far from outstanding.

For the analog output, the real question is how good does a <$100 pair of headphones (maybe MDR-V6?) sound plugged directly into the jack?



The digital output looks fine.


I'm not interested in doing the Mac/PC debate here.

 

[lan]

How this is as a source device depends how you are viewing the item and how you're going to be using it. Of course comparing to absolute "bad" the specs are good. If you just want sound it's ok but many of us are after performance so relativly speaking they are not that great compared to what's out there.

>>>the real question is how good does a <$100 pair of headphones (maybe MDR-V6?) sound plugged directly into the jack?

If you're going to dedicate a machine as a source, why go ampless?

>>>The digital output looks fine.

Can't say how it is unless I were to try and compare it.

>>>I'm not interested in doing the Mac/PC debate here.

Neither am I but what I'm saying is something that I'd question computer, operating system, and software X, Y, Z when considering them as for use in a computer source.

 

[AndrewFischer]

Quote:

Originally Posted by lan >>>the real question is how good does a <$100 pair of headphones (maybe MDR-V6?) sound plugged directly into the jack? If you're going to dedicate a machine as a source, why go ampless?

I realized my error while I was out mowing my lawn. This is what I should have said.

Apple's limited specs give us a general idea of the new iMac's sound quality. Analog looks OK. It looks better than typical motherboard audio. The new iMac's Analog is certainly not as good as an an E-mu 0404 or M-Audio 2496. I'll leave it to someone else to compare with the latest SoundBlaster cards and Chaintech.

Digital is not too bad at all. Digital out is in the range where you should have to spend a LOT of money on the downstream gear to be able to hear the difference.

The real questions are?

1. How does it sound with easy to drive < $100 headphones plugged directly into the jack?
2. How does the analog output sound with good headphones driven by an amp?
3. How does it sound with Audiophile headphones and an external DAC?

Dedicate to source? Hadn't really thought about it. I suppose a few owners will hang it on the living room wall and connect it to the main hi-fi. An expensive jukebox or not, it would be nice to have both objective and subjective evaluations of how it sounds. Looks like we will have to wait another month or so.

 

[Edwood]

Is there an expansion slot like PCI (doesn't look like it) or PCMCIA laptop cardbus?

I guess the jury's still out on the digital output until someone can test it.

If only the new iMac had an active digitizer in it like the Wacom Cintiq or Tablet PC's, then Apple really would have something. But either way, I think Apple has a good potential consumer's Panel PC. The ill fated Monorail computer was ahead of it's time, and looks like the new iMac may bring it back.

As for a computer as a source, not all of them have to be big and bulky. There's is yet hope for PC's too.

-Ed