watchnerd
Headphoneus Supremus
- Joined
- Jul 12, 2008
- Posts
- 2,093
- Likes
- 775
I'm currently using a Nuforce Icon HDP external DAC/Pre/Headphone amp. But it's a little underwhelming in the power department and I'd like to have something with more juice for my AKG 701s, as well as possible additional, more demanding phones I might buy in the future.
While I believe a more powerful headphone amp may be beneficial, do I really need an external DAC?
Could I do just as well by running the line out from my Mac Mini into a headphone amp?
[I'm going to assume for the sake of this thread that the internal DAC of the Mac Mini and an external DAC are both sufficiently proficient at actual digital conversion as to be indifferent and thus we're mainly comparing analog stages.]
Comparison Specs:
Mac Mini:
Frequency Response: 20Hz-20kHz, +0.5 dB/-3 dB
Maximum Output: 1.4V RMS (+5.15 dBu)
SNR: >90 dB @ 1.4V RMS
THD: <-80 dB (0.007%) @ 1.4V RMS
Popular Mid-Price External DAC:
Frequency Response: 20Hz-20KHz, +/-0.1dB
Maximum Output: 2.0V RMS
SNR: >108dB @ 2V RMS
THD: <0.003%, 20Hz-20KHz @ 2V RMS
So there is no doubt that the external DAC has better specs. It's flatter, puts out more volts, has better SNR and better THD than the analog stage of the Mac Mini.
But it if I'm driving an external amp, does it matter?
The only obvious thing I can think of is that 1.4 V vs 2.0 V means that the external amp will need to apply more gain, but with so many 1000+ mW headphone amps on the market, that doesn't seem like much of an issue.
And with the maximum theoretical 16 bit digital noise floor being -96db, and probably less than that in practice, does the theoretically better SNR make any difference?
While I believe a more powerful headphone amp may be beneficial, do I really need an external DAC?
Could I do just as well by running the line out from my Mac Mini into a headphone amp?
[I'm going to assume for the sake of this thread that the internal DAC of the Mac Mini and an external DAC are both sufficiently proficient at actual digital conversion as to be indifferent and thus we're mainly comparing analog stages.]
Comparison Specs:
Mac Mini:
Frequency Response: 20Hz-20kHz, +0.5 dB/-3 dB
Maximum Output: 1.4V RMS (+5.15 dBu)
SNR: >90 dB @ 1.4V RMS
THD: <-80 dB (0.007%) @ 1.4V RMS
Popular Mid-Price External DAC:
Frequency Response: 20Hz-20KHz, +/-0.1dB
Maximum Output: 2.0V RMS
SNR: >108dB @ 2V RMS
THD: <0.003%, 20Hz-20KHz @ 2V RMS
So there is no doubt that the external DAC has better specs. It's flatter, puts out more volts, has better SNR and better THD than the analog stage of the Mac Mini.
But it if I'm driving an external amp, does it matter?
The only obvious thing I can think of is that 1.4 V vs 2.0 V means that the external amp will need to apply more gain, but with so many 1000+ mW headphone amps on the market, that doesn't seem like much of an issue.
And with the maximum theoretical 16 bit digital noise floor being -96db, and probably less than that in practice, does the theoretically better SNR make any difference?