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Examples, Abe.

Hi Abe. You might not have seen the more recent measurements... Over the years I have expanded the repertoire to include evaluations of digital filtering, impulse response, as well as pushing the jitter test to double samplerate as well to stress the system and timing errors.

Here are a few findings that might help - some items that popped into mind as possibly interesting difference shown/confirmed objectively:

1. Have a look at the PonoPlayer results and compare to Stereophile's published results.
PonoPlayer Measurements

- Notice I had no difficulty demonstrating the Ayre impulse response
- Notice the ability to demonstrate the huge amount of aliasing due to Ayre's filtering (and expected by this type of impulse response!)
- Notice the ability to demonstrate the PonoPlayer's high frequency roll-off compared to others.
- Notice in the comparison graphs the Dragonfly 1.2 DAC's tendency towards higher IMD than other DACs (a reason why I don't think the Audioquest Dragonfly 1.2 was a particularly spectacular DAC)

2. Consider the measurements demonstrating the "Digital Filtering Composite" I've been publishing over the last year. Many thanks to Juergen Reis for his ideas and help. For example, you can see a beautiful example of excellent filtering with newer ESS Sabre DACs - here's an example with Light Harmonic's Geek Out V2:
LH Geek Out V2

Compare this with something suboptimal like the 2015 Chromecast Audio:
Chromecast Audio Analog

I have been able to demonstrate limitations of these antialiasing filters even though they're not typically reported elsewhere. Hint: TI/Burr-Brown DACs typically "overload" with strong peaks with their upsampling antialiasing filters. Again, I've had some nice conversations with Jergen who confirmed this in his own internal work (it really is wonderful having an opportunity to discuss stuff like this with the pros grounded in science).

3. Staying with the Chromecast Audio for a moment, even though I can show bit-perfect accuracy, have a look at the TosLink jitter:
Chromecast Audio Digital

In that same post, look at how the Gigabyte Z170X motherboard's optical output performed. I also accelerated the J-Test to 24/96 (I've never seen anyone do this) to demonstrate how jitter increases even further between the devices. Notice how an asynchronous USB DAC (TEAC UD-501) is relatively immune to jitter compared to S/PDIF.

4. Want to show folks how crappy a computer motherboard DAC could measure? Point them here:
Gigabyte Motherboard DAC

Atrocious antialiasing filter performance, rolled-off bass, poor noise level with obvious 60Hz hum, poor intermodulation distortion.

5. Want to emulate Ayre's minimum phase filter used in the PonoPlayer, Codex among others now that we understand how filters work? Look here:
Digital Interpolation Filters

Settings you can try with iZotope RX if you have the program. Can you hear the difference?

6. Here's a cable measurement that showed a difference (Crystal Cable):
Crystal Cable Measurement

I was surprisingly able to demonstrate that the cable in my system performed slightly better in terms of noise floor! You'll have to decide whether the cost of admission is worth it...

7. Want a real objective improvement in one's soundroom?
Updated Room Measurements...

It was a great pleasure to meet and discuss room measurements and DSP room correction with Mitch Barnett who contributes to Computer Audiophile and wrote the E-book on this. Measurements of my own room with both improvements in time and frequency domain correction demonstrated. Objective measurements are not only to figure out if something works, but to optimize our own listening rooms and what we have.

Abe, these are just 7 off the top of my head over the last couple years or so... IMO there is no magic in this. The beauty of computer audio is that we have the software and hardware tools at our disposal to not just experience, but understand. And I hope ultimately to have wisdom when we claim this or that and be able to assign value to what we buy...

The irony I find is that I started my blog about 4 years ago after disagreements with some of the guys here. Some I see have been banned, others I guess have left. It is due to these disagreements and arguments that have set me on this objective exploration and documenting it on the blog! For that, I thank you guys :-).

Apologies for not visiting as much these days... So much to do, so much to explore. Many nuances to understand grounded in the science. I believe the audiophile hobby has to change over time. I believe it will become more objective because, to me at least, it makes sense. Cheers for 2017.

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Archimago's Musings: A 'more objective' audiophile blog.


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  • Examples, Abe. - Archimago 01/13/1720:45:37 01/13/17 (0)

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