@fuzzbutt17 Are you stepping away from the R2R DAC's with the PCM58 DAC chip. This is a Delta Sigma chip correct? How many PCM58 DAC chips are you going to use in the new Z DAC? I am excited to see what you have.
Six DAC Comparison
I am in the middle of comparing the sound of six different DACs in my system. I own them all (I know weird) but one of them is still within a trial/return timeframe.
Not to share specific comparisons today, but a couple of observations so far are that first, they all definitely sound different from each other. On one hand, they all sound pretty good and play what is fed to them without significant flaws but on the other hand there are definite sonic differences that make it easy to understand how a person might like the sound of some of them while not liking others.
Second, raises the observation that most of them must be doing something to shape the sound in the manner the designer intended since one of the DACs, a Benchmark DAC3 HGA, was described by John Atkinson of Stereophile as providing "state-of-the-art measured performance." In the review, JA closed the measurements section by writing, "All I can say is "Wow!" I have also owned the Tambaqui (not in my current comparison), which also measured well ("The Mola Mola Tambaqui offers state-of-the-digital-art measured performance." - JA). The Benchmark reminds me sonically of the Tambaqui, both of which are excellent sounding DACs.
My point is that if the Benchmark is providing "state-of-the-art measured performance," then one could reasonably presume that the other five DACs, which sound different from the Benchmark, do not share similar ’state-of-the-art" measurements and are doing something to subtly or not so subtly alter the sound. Whether a person likes what they hear is a different issue.
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@brbrock Read this on line…“The PCM58 DAC chip is a true multi-bit R2R (Resistor Ladder) DAC and not a Delta-Sigma DAC” |
We're never switching from R-2R to Delta Sigma. (I think I threw up a little in my mouth). The PCM58 is a 40-year-old Burr-Brown 18-bit R-2R DAC chip that was marketed as a direct competitor to the Analog Devices AD1865. It sounds and looks almost identical to the famous 20-bit PCM63. Both the PCM58 and PCM63 are about 4X the size of the AD1862 which I assume accounts for their higher level of performance. Not only are they significantly larger and sound slightly better than the Analog Devices DAC chips, the PCM58 potentially has 4X the number of linearity/distortion fine-tune adjustments. Where as the AD1862 and AD1865 each have one adjustment for the MSB (most significant bit) to optimize linearity and minimize distortion for each channel, the PCM58 has an adjustment for MSB, 2nd bit, 3rd bit, and 4th bit. No small difference. We've had quite a number of PCM58 and PCM63 DAC chips stashed away for over a decade. The reason we haven't designed a DAC with them is that in order to fine-tune linearity and minimize distortion you need to use a very sensitive and very expensive distortion analyzer which we didn't have at the time. We've even had our friend Brial Lowe, the genius behind Belleson regulators, design a custom low-noise amplifier and notch filter for us to assure that even the most subtle noise that could get through to the distortion analyzer from AC mains and RF would be eliminated allowing us to truly optimize these DAC chips to 20-bits of resolution. Here's the kicker.. Among other differences, the entry-level Mystique Z DAC will have only the fine-tune adjustment for the MSB, the middle-level Mystique Z will have the MSB and 2nd bit fine-tuned, and our top-of-the-line Mystique Z will have MSB, 2nd bit, 3rd bit, and 4th bit all fine-tuned. So rather than expecting that Mojo Audio is switching from R-2R to Delta-Sigma expect a level of R-2R performance from our Mystique Z unlike any company has ever offered. And expect a new version of our famous EVO DAC for around $17,000 to be released in 2027 built around Burr-Brown's famous PCM63 DAC chip. |
I look forward to hearing the Mystique Z with the PCM58 DAC chips based on my fond memories of the sound of a Lector CDP-7T/Mk II that I owned. The Mk II used BB PCM63 DAC chips while the CDP-7T/Mk III that I upgraded to used BB PCM1704 DAC chips. I posted this way back in 2008:
If you remember, many of us were chasing resolution back in those days, which is probably why I stupidly upgraded from the Mk II to the Mk III. I remember the guy who purchased my Mk II was an experienced audiophile and I believe an industry insider. He was thrilled to get the Mk II with its PCM 63 chips. I remember thinking that he may know something I didn't, and I was right! While I look forward to hearing the Mystique Z, the one I am most interested in hearing is the EVO DAC with the PCM63 DAC chips that Benjamin has proposed to release in 2027. I suspect that could be the one that will make me forget about my EVO Pro. |
I certainly would not want to offend anyone with my comments. But I'm reading a lot of opinions about I2S, OCXO clocking, and master clocks. I have no doubt that those of you who have heard this or that component with OCXO clocking or I2S inputs or master clocks and preferred the way they sounded are 100% correct. But that doesn't mean that all components with those inputs, outputs, or clocking sound better. There are too many other factors. I2S was never intended for component-to-component data transfer. If you don't believe me, why don't you look up the Audio Engineering Society's specification on I2S which clearly states that it should not be used for distances over 4" and that it is only intended for inside of a DAC chassis. Personally I would trust the Audio Engineering Society over any audiophile fad. Show me any equipment used in recording studios that uses I2S between components: last I checked it doesn't exist. The preferred data transfer between components in recording studios is still balanced AES. Consider what I2S actually is doing and decide for yourself if it is even logical. The proponents of I2S claim that clocking which is embedded into the data stream can become corrupted during data transfer. So how would it make sense that by having data embedded with clocking along with a bit clock and a word clock could synchronize better?!?!?!? If the clocking embedded in the data gets corrupted, then the data would be corrupted, and the data could not synchronize with the other two I2S clocks. Think about it. Not to mention the fact that all Audio Engineering Society standard digital music transfer protocols have the clocking embedded into the data stream. Yes, USB, S/PDIF, AES, Ethernet, etc., all have clocking embedded into the data stream. That would mean that the internet music streaming services that most people are using have clocking embedded into the data stream and the data stream is traveling cross-country. Do you really think that after the clocking embedded in the data stream has traveled for miles and miles and miles over the internet that isolating clocking for 1 meter by doing I2S from your streamer to your DAC is going to correct something? LOL! As for OCXO clocking or master clocks that's another common misconception. OCXO clocks were never originally engineered for high-end audio. They were engineered for electronics that are subject to extreme weather conditions such as those used in submarines, aircraft, missiles, rockets, and polar expedition vehicles. Some audio engineers discovered that OCXO clocks had lower hash noise in the audible spectrum and started to use them. But OCXO clocks are generally less accurate than femto and other clocks engineered for high-end audio. So using OCXO clocks is generally a tradeoff. Consider the problem with clocking noise is that it pollutes the other power supplies inside of the DAC. This is one of the main reasons why external master clocks are used: they completely isolate the clocks power supply from the power supplies inside of the DAC and other digital components. At Mojo Audio we take a different approach: the LC choke input power supplies we use in our analog power supplies are so much better isolated than those other companies use that clocking hash noise from our femto clocking can't corrupt it. This way we get the best of all worlds: the increased accuracy of femto clocking, less clocking noise in our analog power supplies, and less clocking corruption than happens with external master clocks connected by long cables. Also note that our AES and coaxial inputs have no internal clocking or reclocking. That way you can hear the full benefit of whatever the clocking is in your CD transport or streamer. That's why customers and reviewers who have used our DACs with uber CD transports like the Jay's CDT-3 MkIII tell us the sound rivals or beats their vinyl rig. We even have a unique USB lift switch that eliminates 100% of the clocking inside of our DAC chassis when using the AES or coaxial inputs. Bottom line: I recommend that you trust your ears. Customer after customer and reviewer after reviewer have compared the sound of Mojo Audio DACs using our USB, AES, or coaxial inputs to most of the popular DACs who use I2S or Ethernet inputs or OCXO or master clocks and they have consistently preferred the sound of our DACs. I think that says it all. |
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