First impressions of new MH-DA006, Musetec flagship

@melm Its a crystal oscillator enclosed in an oven which makes it an OXCO. Both quality of XO and the quality of the power supply for the oven are critical for highest performance. The exact implementation within Gaia is only possible by reverse engineering, manufacturers don't want to reveal all. In any case sound quality is always my final arbiter of quality, Gaia transforms 006 into an even better dac vs using usb input.

I've been experimenting using Gaia clock vs 006 internal clock, Gaia clock exposes 006 as an inherent limitation of this dac whether using usb or I2S inputs. Going usb even more of a limitation in that Gaia exposes it as inferior even when using 006 internal clock via I2S. So two benefits of Gaia, inherent superiority of I2S and superior OXCO clock.

Using Gaia's clock vs internal clock. Easily and immediately heard expansion of sound stage, images more dimensional and greater density, great sense of reach out touch performers. Gaia using 006 internal clock, flatter perspective, sound stage shrinkage, sense of less resolution as images congeal and sound stage shrinks. 006 via usb, further shrinkage of ss and images, less analog presentation.

@sns But what is engineering? What is marketing? The bottom line is that we don’t know anything about the clocks inside the Gaia except that they are OCXOs. As I said earlier, inside the OC there is an XO clock whose properties seem a mystery. I take what you wrote to mean that the Gaia’s USB output can can outperform the Amanero board within the 006 using LKS clocks, though better performance is by I2S out. Whether that is due to the clocks or some other factor within the Gaia, including the possibility of a better PS to the clocks (which I have proven to myself really helps) may be a question.

Goldensound, who is a very serious guy, has reviewed the Gaia. In the review he says among other things, "Overall, the Gaia is an excellently performing DDC.  It falls ever so slightly behind some other choices like the [Audio GD] DI20HE and [Singxer] SU6 in performance" It turns out that the D120HE uses Accusilicon clocks like the ones I am using in a new streamer; the SU6 uses Crystek clocks. These are unfortunately only Femto clocks. The clocks inside the 006 are (perhaps) LKS optimized Crystek clocks that are available from Asian sources. For all of these clocks, and for any that I have seen (including the expensive clocks that are on my shopping list) there are specification sheets available so one may compare some, if not all, of what they do. But not for the Gaia OCXOs. The bottom line, of course, is the ear.

Here's a summary of clock considerations from MSB:

https://msbtechnology.com/dacs/clock-options/

To summarize, the most important aspect of clock implementation is the elimination of jitter and phase noise, not the type of clock and its supposed accuracy (ie OCXO vs Femto etc.). External clocks are a poor choice due to the introduction of jitter from the additional cabling.

@melm First off, as I mentioned previously reverse engineering required to determine quality of these clocks and power supplies, manufacturers rightly don't advertise their schematics and all part numbers.

As for usb vs I2S I've never stated all I2S implementations will beat all usb implementations, my previous experience with SU 6 and 005 being inferior to ubs proves this out. Golden Sound replicates ASR in that measurements tell all. I presume all 005 owners understand the fallacy of this what with it's poor performance over at ASR. More proof of this folly is my experience with Okto Stereo dac which at one point was SNR champ at ASR, jitter right up there as well. So, Okto vs 005 which measures poorly. Sold the Okto, kept the 005, amazing how a dac with lousy SNR was more highly resolving than top rated Okto. My point is one should pick the Singxer SU6 over the Gaia if measurements are your final arbiter for equipment purchases. I've had both in house, Gaia wins on build quality, design and sound quality. As for the Audio GD, I can only speculate as to it's performance, I chose the Gaia, happy with the purchase, especially with the Tubulus cable.

 @catastrofe I understand the theoretically inferiority of external clocks via I2S interface. Well usb is also a very flawed interface, never designed for the purpose it's used for in dacs. Think about all the complexity of usb boards within dacs, lots of technology required to clean up this flawed interface. Back to I2S, well Gaia external clock beats out 006 internal clock, and not by just a bit, so much for theoreticals. Still, I'd advise sticking to 1/2 M or less for I2S cables.

Bottom line, I agree we should be concerned with design, parts, build quality, and measurements. After decades spent in audio, I treat measurements as perhaps the least important aspect for end users. Measurements are of critical importance for designers/engineers, not so much for us. Musetec, in their own statements admits their final designs based on listening vs measurements. I presume many other manufacturers do exactly the same.

@sns 

If USB is so flawed, why hasn't the market driven it to the trash bin? Every DAC manufacturer has the ability to provide an I2S and/or external clock input, yet most don't even though it would provide an enhanced revenue stream in the form of DDC and clock sales.

The top DAC manufacturers (DCS, Weiss, MSB, Wadax, etc.) eschew the use of I2S for USB. Sonore doesn't provide an I2S output on their Rendu devices because they found that implementation matters more than the "format". Jusi Laako, founder of Signalyst/HQ Player is fairly vocal regarding the negatives of I2S due to the clock being so far removed from the DAC.

PS Audio was one of the first manufacturers to promote I2S in their original PerfectWave DAC for which I was a Beta Tester. At that time (~2007) I was all-in on I2S and it definitely sounded better than USB. As technology has progressed, improvements in USB isolation and better clock implementations have reduced any perceived benefit provided by I2S.

If you feel that your system sounds better via I2S compared to USB, great, but that doesn't mean it's empirically better and it's certainly not an absolute.