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"In my September 2015 column, I reported on the coincidence of my reference DAC, the exaSound e28, and my reference music player, the Baetis XR2, being updated at the same time…. Well, lightning has struck the same places again. Above, I describe the evolution of the e28 to the e38 – and now I get to report about a new, smaller, more advanced Baetis server, the Prodigy X. And, with even more bells and whistles than the XR3, the Prodigy X costs less!

(the Prodigy X) represents another evolutionary step in an already distinguished line. Like its predecessors, the Prodigy X is a fully configured music engine with all the software needed to rip CDs and BDs, and to play any music-file format from directly attached or networked sources.

I am unrepentant. The Baetis Prodigy X is more compact, equally capable, and less expensive. If it’s a little better, too, why argue?" Kal Rubinson, Stereophile, July 2017 (on the new Prodigy X).

"Having now had some time to really listen to the Prodigy X from ripped CDs I am very familiar with, I can truly understand the efforts and dedication of John Mingo et al to develop and continue to enhance the Baetis line of media servers. The difference from my prior media server in playback through the same equipment and AES/EBU interface (but with a different AES/EBU cable) is very, very noticeable across the spectrum (pitch, timbre, air, bloom and decay) with layers of what I now realize must have been "background" noise from the prior media server's standard interior PC motherboard, plug-in boards, drives and power supply no longer in evidence. You are there is much more "there". And my previous media server purchased direct sells for the same price as the Prodigy X, but is really no comparison in fit, finish, graphics, transport, etc.

I only hope that you can "get the word" out to fellow audiophiles about this amazing media server and the quality inherent in the entire line of servers. It is really no contest, but how to get the public to find the better mouse trap is always hard…."
J.S., on the Prodigy X, Anchorage, AK, March, 2017

“Being an old-school audiophile, I had been procrastinating for many years about getting into computer audio… One of my main reservations was that I feared the sound would not be emotionally engaging. And isn’t that we listen to music for, so it can speak to our heart? Well, I have good news on that front.

But to begin, I must admit I was confused with all the acronyms I encountered in researching your products. USB, HDMI, AES/SBU….. But what I quickly discovered is that you forgot one: IMM. That’s for Involuntary Muscle Movement. More on that later.

With the sound of the Baetis Prodigy 2 with AES option, I frequently find myself irresistibly drawn into the musical experience. I often connect with the music in a way that has been all too rare in the past. It’s an emotional thing. I marvel at how great a particular artist and their creation is. How it forms such a heart to heart, soul to soul connection.

If I’m in another room, I find myself running back, lunging into the sweet spot on the couch and reaching for the volume on the remote. (Good thing I don’t have a cat!) Since receiving the Baetis, I’ve been playing my stereo more than I have in years. I should mention that I was previously happy with my $6,000 CD player as the source.

All audiophiles know that an upgrade to our system is an incremental thing, and hopefully in a positive way. But this time it’s more than a subtle improvement, it’s a whole new world of sound! I now own one of the most musically engaging stereos I have ever heard anywhere, including in showrooms with six figure systems.

I previously had mentioned my new acronym IMM, for Involuntary Muscle Movement. This new sound just gets you head boppin', foot stompin', booty wiggling couch-borne jazzercising, whether you want to or not! With the Baetis, "Resistance is futile, you will be assimilated….". In fact, in the two months since it arrived, I’ve worn out one carpet, two couch cushions and 11 pairs of shoes!

To add to your list of accolades, I hereby announce the Baetis Prodigy 2 as the recipient of the esteemed "Bob Award" for 2017.
R.G., on the Prodigy 2 with AES option, Wilderville, OR, March 2017

"In a real sense, the Baetis Reference is the product I’ve been waiting for since that profoundly disappointing moment in 1983 when I first placed a compact disc in the drawer of a newly purchased Sony CDP-101—and decidedly did not hear "perfect sound forever." Over the past three decades, digital’s deficiencies have been steadily mitigated, and I’m now ready to say that the technology’s potential has been fully realized. I can’t imagine enjoying music at home to the fullest extent possible without the Baetis Reference and will be returning the warranty card that came with the review sample along with a check. If you’ve embraced the digital future and have the means and the motivation, you must make a point of experiencing what this remarkable machine can do."
Andrew Quint, The Absolute Sound, December 2015

"...the best digital sound I have ever heard in my system." (reviewing the Revolution II)
Andrew Quint, The Absolute Sound, issue 240, February, 2014" read article

By far, the XR2's (special) S/PDIF output produced the best two-channel sound over every DAC I tried, and at all resolutions from 16/44.1 through 24/192 and DoP (DSD over PCM)."
Kalman Rubinson, Stereophile, September, 2014, pp. 61-65 read article

"All of the presets delivered on the promise of the best possible sound; this was the best I've heard my system sound to date." Kris Deering Sound &, June 12, 2014 read article

"...I’ve now been living with this unit for about 3 months and I can tell you it has changed the way I listen to music..."
M.W., Kansas

"...the customer service is even beyond that of the music quality..."
W.A., Arizona

"The server works perfectly; it is a real upgrade from (the) $6k Naim CD player!"
M.B., Quebec

"WOW -- @#!!* – WOW!!" From P.B., Charlotte, NC, on our XR3 model.

"I never thought a computer could make this much of a difference….a turning point in digital audio." From M.P., Sao Paulo, Brazil, on our Reference.

"Frankly, I did not expect the magnitude of change to be this huge from the Revolution I model….you have once again delivered a product of sterling quality and value."
From A.K., Singapore, on our Revolution III.

These reviews by professional reviewers and by Baetis owners are just the tip of the iceberg. The Baetis Reference server was used by Magico speakers at CES2015 and at RMAF 2015. Both the Magico room and Kharma room used our Reference at CES 2016 and CES 2017. Magico also used the Reference at RMAF 2016. Some of our clients (we don’t call them customers, because of the close personal relationship our customer support folks have with our users) have systems that will blow your mind – Magico Q7’s, Spectral amplifiers, dCS Vivaldi DACs, -- and listening rooms that have the very best in physical acoustical treatment. To get a feel for how serious these folks are about highest quality two channel audio, take a look at the following slide show of Magico’s showrooms in Hayward, California.
Baetis Reference Photo Show

This process of developing two-channel sound that many believe is the best out there, regardless of price, took us more than 4 years of 60 hour weeks. We spent a LOT of money trying different alternatives, including computer components, handmade internal wiring, various EMI-reduction treatments, and, especially, our proprietary circuit board that takes a VERY good SPDIF signal straight from the motherboard, and improves it quite significantly. We have proved that our approach beats USB or SPDIF/AES via PCI cards.


Negative reviews

No high-end audio product is without negative reviews.  We ask you to be very careful when you read these on the internet.  First, there are any number of comments on audiophile sites from people who have never actually auditioned any Baetis product.  These reviews should be valued for what they are – skepticism based on how we describe our products, when the commenter simply doesn’t understand what we are trying to do.  Some of these comments come from electronics engineers.  The most egregious such comments come from a particular competitor who has since taken down his diatribe.  You might be quite appalled by the tone of his comments – it is one thing to be a skeptic, it is quite another thing to call a competitor names.

Please note that we are repeating these criticisms here, and our responses, because things have a life of their own on the internet.  We simply call the competitor “Competitor.”


Baetis' web site and white papers are replete with marketing hype, bad science, and technical fallacies. As usual, we cannot comment on the products themselves as we have no direct experience with them. The products might achieve the performance they claim, but if they do it is unlikely that the marketing claims accurately describe what actually accounts for the performance.

Our PhD electronics engineers have their degrees from perhaps colleges of lesser renown than Competitor’s alma mater.  But they do specialize in digital audio electronics, and we have tried to explain what they have told us in language that a non-PhD can understand.  Any remaining errors are solely our own.


The brochure (captured 10 Jan 2015) "Introducing the Baetis Reference Media Server" explains that the switched-mode power supply must be outside the box so that "the EMI [electro-magnetic interference] ... cannot harm the audio". Baetis is referring to the main power supply for the system, but computers have other switched-mode power supplies as well. Computer motherboards typically have several, and the latest generation of Intel CPUs has a switched-mode power supply in the CPU itself (Intel calls it the Fully Integrated Voltage Regulator). All switched-mode power supplies produce EMI, so how can Baetis ignore the threat to audio quality posed by the remaining ones?

We agree that there are switch-mode power supply units inside the computer -- typically ones producing low voltages and mainly in the form of DC distribution circuits.  But we do not want to compound those EMI emissions by putting the main PSU inside the computer. All our current Reference models come with an HD-Plex Linear Power Supply, with a cryo-treated DC cable. If Competitor’s computers do have internal main PSUs, we assume that they are completely covered in metal, preferably nickel alloys such as MuMetal™, to minimize EMI -- as is the case with our proprietary daughterboard.  We do that to keep the daughterboard from being bombarded by EMI from all the other parts of the computer.  With the PSU, the housing and its placement are outside the computer to keep the PSU from contaminating the other components of the computer.  Is Competitor’s internal PSU covered fully in metal?

More to the point, does Competitor’s server contain internally any kind of anti-EMI materials such as EMI-reflecting material or EMI-absorption material?  Our Baetis servers all do.  Competitor, these pieces of fabric are the secret to reducing EMI within the computer, once the PSU is outside.  We are giving away this trade secret because it is not among the most important things in producing the best audio, but you do have a lot of questions.


Computers with fans are greatly noisier than computers without fans. If you cannot hear the fan noise because other noises in your listening room dominate, then you might be content – or perhaps you need a quieter listening room. Also, the claim that all fan-less computers reach "internal temperatures that compromise longevity" is blowing smoke. The Wax Box, for one, does not because it uses heat pipes to remove heat passively.


There are several considerations here. All our CPUs in every server use heatpipes, not fans for cooling.  We use a fan specifically for cooling only the MB, not the CPU, in just some of our models. Our fan has a claimed noise of about 7 dB in an anechoic chamber;, is Competitor saying that he has measured the noise of his server with a digital sound pressure meter, and, if so, is he saying that its readings are less than 7dB?  Also, importantly, what are the dB readings in his listening room with the sound system not on at all?  Is it less than 7 dB?  Perhaps Competitor has significantly better hearing than a digital sound pressure meter.  Or, perhaps he wasn’t breathing when he took the sound pressure measurement.  Our reviewers and users all say they can’t hear the sound of our MB-cooling fan at all, even close up.  We therefore congratulate Competitor on his great ears.

The next question deals with heat measurement on the MB as well as the CPU.  What are the heat measurements on the MB when a fan is NOT used to cool it, and when the user is playing something that generates a lot of heat such as a multi-channel SACD file or a multi-channel Blu-ray file?  Or, is Competitor asking his heat pipes to cool both the MB and the CPU, and his heat sink + heat pipes are indeed better than the heat sink + heat-pipes used to cool our own CPU.   We are not satisfied with the heat measurements on the MB until we use a Noctua™ fan that has the claimed noise measurement of 7db.  What are Competitor’s heat measurements on his MB when playing other than low-resolution 2-channel audio? 

Also, we have measured several listening rooms and the high 20’s in decibels is a really good listening room.  In passing we can’t resist saying something catty about electronics engineers.  Many we have met tend to build things based on metrics and “rules of thumb” that are 30 years old (see our discussion below on digital signal amplitude).  Or, some engineers say things like “fan-less computers are noiseless.”  Sorry, maybe our digital sound pressure meter is too inexpensive at less than $200.  As we say elsewhere on our website, heat pipes work by transferring heat to fins on the outside of the computer.  This causes air to rise from those fins.  Moving air CANNOT be noiseless.  What brand and model of sound pressure meter does Competitor use?


In their announcement [home page (captured 10 Jan 2015)] of the Revolution III, Baetis unveils a "critical printed circuit board (PCB)". In one paragraph, they say that the purpose of the PCB is to improve the S/PDIF signal "by showing a more perfect digital signal waveform than the original signal, with increased voltage (amplitude) of the signal". This statement provides an example of a rhetorical trick popular with charlatans, the unproven premise. A more perfect digital signal waveform and increased voltage are axiomatically good, so of course you want a product with this magical PCB. Well... What exactly was wrong with the "straight-from-the-motherboard SPDIF signal" that required improvement? If the signal was defective in some way that required correction, what magic does the new PCB possess that permits it to figure out the correct waveform? Why couldn't some circuitry at the other end of the S/PDIF cable (i.e., in the DAC) perform the same magic instead of the PCB? What exactly is "a more perfect digital signal waveform"? How does perfecting the digital signal waveform affect the "accuracy and musicality for 2-channel audio" when the audio is represented by numbers whose values are unchanged by manipulation of the digital waveform? There are answers to questions like these, but Baetis does not provide them.

In the next paragraph, the purpose of the new PCB is different. Here, we learn that the new PCB "improves audio quality and somewhat higher volume through virtually all DACs". If I interpret the poor grammar correctly, Baetis is ascribing two other benefits to this new PCB: (1) improved audio quality, and (2) higher sound volume with most DACs. Baetis provides no explanation as to how the new PCB achieves these goals either. Isn't it possible to get "somewhat higher volume" simply by turning the volume control? And by the way, how does the mysterious PCB increase the volume? The PCB is in the path to an external DAC, so the audio signal is a digital stream encoded as S/PDIF. To change the loudness, the PCB would have to decode the S/PDIF stream, multiply each number that represents the audio signal by a number larger than 1.0, and then re-encode the digital audio as S/PDIF. If there were circuity on this PCB capable of performing such operations, presumably Baetis would at least have hinted at its presence.

We have repeated Competitor’s discussion of our daughterboard in full because this board is so central to the quality of our digital audio output via SPDIF and AES.  Competitor’s comments seem quite clear to us.  He is not able to imagine why a separate printed circuit board might improve audio quality or why there isn’t some way to simply obtain the better digital signal to begin with on the motherboard.  We certainly congratulate Competitor if his server, via either SPDIF or AESid, sounds better than a Baetis (although the latest review shows just the opposite).

But no, we will not give away the construction of our daughterboard.  Even Competitor, however, can guess what component on our board might produce higher amplitudes on the SPDIF signal than the voltage coming from the MB.  The real question is why is higher amplitude so important?  Competitor is honest enough to actually ask this question.  Our answer is that we don’t know because our engineers are not experts on the digital-to-analog process and we expect the user to have his own quite good DAC.  [As an aside, our products do NOT contain usable DACs, just digital outputs.  No one would use the DACs in our computer because it starts with a factory motherboard.  These DACs produce absolutely atrocious analog signals.  Perhaps Competitor thinks that we actually use the DACs on our factory computer MB?  Certainly “computer audio” has come far enough so that no one, not even a highly academic engineer, would believe that “computer audiophiles” would use the analog outputs from a computer].

To answer Competitor’s question, we think, but cannot prove, that certain DAC makers design their SPDIF inputs to take much higher voltage inputs than the 30-year old standard of 0.6 volts.  Similarly, their AES inputs seem to sound much better than other DACs’ AES inputs (and, for sure, these other DACs’ USB inputs), and these AES inputs sound better when the AES signal coming from the server is in the middle to high end of the 30-year old specification of 2-7 volts.  This is much higher voltage than SPDIF or AESid, and it is this higher voltage on SPDIF that we guess makes some DACs sound lots better than others.   But we are not DAC builders.  Competitor is a DAC builder and he should know; or perhaps his Server + DAC model is one third the price of a Berkeley Reference DAC for a reason.

Yes, Competitor, you have probably now figured out that there is at least one other element of our daughterboard besides the thingy that increases amplitude.  Yes, we get our AES signal from a SPDIF to AES transformer on the daughterboard.  Now, we’re sure you’ll have criticisms of this transformer, but we are not giving it all away.  You’ll just have to do what we did – either a lot more reading, or the hiring of a different set of engineers – then, a LOT of actual auditioning, to figure out which brand and model of transformer sounds the very best.  We even have two types of daughterboard – a less expensive one for use in our Prodigy models (which also sound better than almost all other servers), and a more expensive daughterboard in our Baetis models.  Since you only read our January 2015 website, we had not yet introduced our Prodigy servers.

Finally, yes you are correct that the daughterboard provides galvanic isolation as well as a “better looking” digital signal, more amplitude, and lower rise time.  We initially guessed that the best DACs really don’t need that galvanic isolation to take place in the server, just as you assume, but we were just being careful (but read on).

When you speak of galvanic isolation you speak of it in terms of elimination of ground loop hum.   Many of our potential clients also think of it this way, even the ones who didn’t go to grad school.  But you should understand that the reduction of common mode noise is still a premier consideration, even when no ground loop noise can be heard.  We do know that the less common-mode noise there is the better the audio sounds, so getting rid of ground loop hum is just a start.  And, of course, all digital audio signals are in fact electrical signals.  Thus, achieving the lowest possible common mode noise in any electrical signal is (or should be) an aim of all engineers in our industry.  Here is a site that provides a brief discussion of common mode noise and it suggests that less such noise is always better, ceteris paribus:

Competitor, we expect that you will have many negative things to say about the author of this post on the URL above.  Please understand that I (John Mingo, Baetis Chief Designer) have read this site, and I printed the URL, not our engineers.  Our engineers have much more important things to do besides entering into an internet exchange with you, given your propensity for arguing instead of designing.

The point here is that this “don’t stop at eliminating common-mode HUM” issue is VERY important, we believe.  The common-mode noise effects on audio quality can be tremendous, and we have talked with DAC engineers who include common-mode noise reduction as a major item among more than 50 separate steps in achieving the best D to A process.  This suggests to me – someone whose PhD is NOT in electronics engineering – that it might be perfectly reasonable to insist on galvanic isolation at several points along the way from the MB to the DAC chipset in the DAC.  Again, Competitor, your comments sound like frustration because you haven’t learned enough.  Believe me, I share your pain. But unlike you, I believe in audition as the only way to know for sure if additional galvanic isolation improves audio quality. 


One final observation: Notice in the Product Details (captured 10 Jan 2015) for the Revolution III that free technical support is limited to 4 hours. In their FAQ 7 (captured 10 Jan 2015), Baetis says that many customers require more than 20 hours of support to learn how to use the JRiver software. They themselves claim that "the educational process for JRiver simply doesn't exist outside of our own methods", so don't expect the JRiver wiki and forum to provide worthwhile assistance (it will "take hours to obtain an answer to a simple issue"). You better find out what Baetis will charge for the additional 16 hours of training they say you will need to learn how to use JRiver software. Oh, and if you go for "optional installation of the very best CD ripping software – dBoweramp", then you might need additional help learning to use that software as well. Decide for yourself whether this policy is consistent with the statement "we live by our customer service – if it is not the best, by a wide margin, then we have not met our business objectives" [home page (captured 10 Jan 2015)].

Even as slow as we are, we get the implication.  Pricing for support, you are implying, is a scam.  Bait and switch?  Why didn’t you say that out-loud?  Is this the “gentle” version of your commentary? 

Well here are the facts: The 20-hour average is no longer on the website because it is no longer true.  The Absolute Sound used that number as well and we replied that this is the mean (almost 3 years ago) not the modal number. We have a very few clients who are either highly limited (e.g., Alzheimer’s) or they ask us to help them with computer things having nothing to do with music, and in our early life we complied with all such requests.  Additionally, we have started to make some much less expensive servers, aimed at customers who might not need as much customer support.  Furthermore, as a new company 6 years ago we had only a few customers, so yes, the average customer support time was quite high.  We assume your average cost of support is much lower because you sell so many of your servers.

Today, we take great pains to understand the customer’s system and his abilities with respect to a Windows OS.  And we, several times a year, convince a potential customer NOT to buy a Baetis – either because he is totally frightened of computers, or his DAC is so poor that even our great SPDIF/AES signals cannot improve the analog output from his DAC. We know which DACs these are, due to the money we spend on auditioning DACs and the reports we get back from Baetis customers.  With our Reference models, support is unlimited for a full year.  And we lowered the estimated cost of support and therefore the price of the Reference when we had more data on the actual number of support hours.  There are essentially no Baetis customers that need support past the first year (except for the one bed-ridden customer we have, and we don’t charge extra for this person).  If you can’t figure it all out by the end of 1 year, then yes, the Baetis is not for you. 

But the modal support hours are now about 4 hours, including the initial 90-minute set-up session.  The low prices for the Prodigy models are due, in part, to us having just priced into the unit the modal cost of support, not the mean.  Even so, we are extremely generous with how we count those hours if the support system is not being abused. We charge our actual support cost ($45/hour) for support beyond the limit on those models.  Perhaps labor costs are lower in Colorado than Montreal?  Or perhaps you don’t personally believe in the economics of pricing support separately for those clients who are slow learners or those who think they can get unlimited support for problems associated with their cheap routers or their continuous mistakes when they “tweak” the settings in JRiver Media Center.  And we assume that you also don’t think prices should be lower for people who don’t need a lot of support.

We price the Baetis Reference models higher not because of needing more support but mainly because of the higher cost of the components in the Reference series that are not available in the Prodigy series:

A better version of the daughterboard for AES output; a better version of the Realtek audio codec; all cabling in the Reference models are cryo-treated for better signal quality (including internal DC cabling and SATA cabling); the critical cables for the AES output are pure silver cryo-treated cables; the daughterboard has a hand-built EMI shield; when employing the SOtM USBhubIN board + associated clock board in the Reference models, all of the USB internal cables are cryo-treated; all Reference models come standard with the very best external linear PSU with the very lowest measured ripple/noise (the original Reference model mentioned by Competitor had a switch-mode PSU; and, finally, the Reference models all have a very much better optical Blu-ray drive – the best available).

Finally, we have to say that we have learned the most from our discussions with various OEM equipment designers, which sometimes lead us to try new things.  The engineers in which we have the most confidence are those who do think outside the box and there are very few of them.  The ones that we respect the most all say one thing – auditioning their own products, continually, is a key to producing the best sound.  Therefore, a very important question is – what is the 2-channel audio system on which you test your own designs?  If you can’t produce a product that shows improvement on a very good audio system, then it surely won’t produce better results on a lesser system.  So, Competitor, have you listed on your website the system(s) you use in auditioning your products?  I apologize if I missed it.  As discussed elsewhere on our site, we have two reference rooms (plus some other less expensive rooms).  Our two best rooms use Wilson Audio Sasha and Wilson Audio Maxx speakers, and both rooms use Berkeley Reference DACs Series 2’s with MQA firmware upgrades). One of these rooms also uses a T+A™ DAC for DSD up to DSD512.  


Negative review at an audiophile site of our Revolution III server by Michael Lavorgna.

Please read the full review at

The review does provide a very useful bit of information.  The reviewer found that his PSAudio™ DSD DAC sounded about 5% better via its AES input rather than its USB input.  This is very important because it tells us that we were erroneous in characterizing the PSAudio™ DSD DAC as a “USB centric” DAC – i.e., one that sounds best via its USB input.   We apologize to Paul McGowan for having too quickly judged his DAC, and we will not make that mistake again.  Plus, we are one of his biggest fans for his long service in the audiophile community and his many accomplishments.