Antelope Audio Zodiac Platinum DAC with 10M Rubidium Atomic Clock Review

Antelope Audio Zodiac Platinum DAC with 10M Rubidium Atomic Clock Review Highlights

Secrets of Home Theater and High Fidelity - John E. Johnson, Jr.

Antelope Audio is a company originally based in the USA, but is now based in Europe, with the factory in Bulgaria. The manufacture DACs and A/D converters for the Pro industry (recording studios). However, they also offer these products in a high end consumer edition. The Zodiac Platinum DAC with an outboard 10M Rubidium Atomic Clock is their latest set of DAC components for audiophiles.

The Zodiac Platinum DAC is shown below, along with the outboard Voltikus power supply on the right, and the 10M Rubidium Clock on the left.

The 10M is not a “Master Clock” per se, but provides a 10 MHz reference to the clock that is inside the Zodiac DAC chassis. It operates when the it is connected to the Zodiac DAC, and is accurate to 1 second in 1,000 years. The 10M was used in scoring (the music) for Avatar, and is now used in the production of many major films out of Hollywood.

If you turn off the 10M (or don’t have one), the clock that is integral to the Zodiac DAC chassis is used as is, without an additional reference. So, there are two ways you can use the Zodiac. The 10M is really for situations where someone wants to have the most precise timing that is available, and the Pro industry (recording studios) needs this.



The Zodiac Platinum DAC with the Voltikus Power Supply are priced at $5,500 USD. If you want the outboard 10M Rubidium Clock with the Zodiac, the total is $12,995 USD.

The Zodiac DAC will decode PCM up to 24/384, and DSD up to DSD128, so the DAC is fully up to date with codec firmware.

The sound of this three-some was marvelous, with some of the best detail clarity I have ever heard. Music from the 1960’s produced new detail that I never knew was there, either in the original analog LPs, or the CD versions. And this is the first time I have ever been able to actually hear the difference between 24/96 and 24/192. There are two 1/4″ headphone jacks on the DAC front panel, and the sound through the HiFiMAN HE-500 and OPPO PM-1 planar magnetic headphones was fantastic.

Although the USB input is Adaptive-Asynchronous, meaning it is not asynchronous, the distortion levels were about the same as they were with the AES (XLR, Balanced) connection, which surprised me, as I expected the adaptive-asynchronous circuit to result in more distortion. However, I had to download a software player (JRiver) to get the low distortion with the USB input. The native Windows music player gave a high noise floor artifact. This emphasizes how important it is to select the right software music player for using the Zodiac DAC through the USB input.

The user interface is a bit confusing, requiring a lot of e-mails back and forth with the Antelope Audio technical staff. The software interface allows you to select the input volume (called “Calibration Trim” by Antelope) in dBu, which is for the analog inputs if you are using the component as a preamplifier, and the analog output volume, also in dBu. The front panel of the Zodiac has a volume (calibration trim) control too, again, in the analog domain, and you can use your mouse to turn the knob in the software interface. The three “Trim” controls are used by recording studios for precise setup of playing recordings during the production process. For the consumer, this means getting the best balance of voltage going to your preamplifier. Stepped attenuators, matched to 0.05 dB, are used to control the volume (calibration) in all instances, including the two headphone jacks.

Antelope Audio Zodiac Platinum DAC with 10M Rubidium Atomic Clock Review Highlights Summary

  • Very clean, detailed sound
  • Plays all current high resolution music files
  • Very high performance clock reference, and power supply, are in separate enclosures
  • Instruction manual needs re-writing to explain the software interface in more detail


Introduction to the Antelope Audio Zodiac Platinum DAC with 10M Rubidium Atomic Clock Review

Antelope Audio produces high end DACs and A/D converters for the Pro industry. They also sell versions made for audiophiles, although you must use the lowest output setting, 14 dBu (to produce 4 volts at 0 dB) for connection to your preamplifier, as the other output settings (up to 26 dBu) produce voltage that is used in Pro venues, and which is too high for a consumer preamplifier.

The system that came to me for review included the Zodiac Platinum DAC, the Voltikus Power Supply (powers the DAC), and the 10M Rubidium Atomic Clock.

The Zodiac DAC chassis has its own clock, but addition of the 10M delivers 10 MHz reference capability and timing accuracy to 0.03 parts per billion. There is virtually zero jitter.



  • Zodiac Platinum DAC
  • Design: Stereo DAC
  • Codecs: PCM up to 24/384, DSD up to DSD128, flac, wav, alac, aac, aiff, mp3
  • DACs: Two Stereo TI PCM1792
  • Inputs: One Balanced Analog 1/4″ TRS, One Pair Unbalanced Analog Coax (RCA), One AES Digital, Two Coax (RCA) S/PDIF Digital, Two Toslink Optical Digital, One USB Type 1 (Connect to Computer)
  • Outputs: One Pair XLR Analog Balanced, One Pair Analog Coax RCA, One AES Digital, Two Coax (RCA) S/PDIF Digital (de-jittered), Two 1/4″ Headphone Jacks
  • Other Connections: One BNC Umbilical for Connection to 10M Atomic Clock, One Umbilical for Connection to Voltikus Power Supply
  • Upsampling: Switchable On or Off, 8X, 64 Bit Precision, Used Primarily for DSD Music Files
  • THD+N: 0.0008%
  • Remote Control Included
  • Dimensions: 4.4″ H x 6.5″ W x 6.6″ D
  • Weight: 4.4 Pounds
  • MSRP: $5,500 USD (for Zodiac and Voltikus)
  • Voltikus Power Supply for Zodiac DAC
  • Input Power: 120V – 240V; 50 Hz – 60 Hz
  • Output Power: 18VDC
  • Dimensions: 4.4″ X 4.2″ x 6.6″ D
  • Weight: 5.5 Pounds
  • 10M Rubidium Atomic Clock
  • Clock Frequency: 10 MHz
  • Timing Accuracy: 0.03 Parts per Billion
  • Connectioins: Umbilical to Connect with DAC, Grounded AC
  • Dimensions: 4.4″ H x 4″ W x 6.6″ D
  • MSRP: $12,995 USD (for Zodiac, Voltikus, and 10M)
  • Antelope Audio
  • Tags: Antelope Audio, DACs, 24/384, DSD128



The Design of the Antelope Audio Zodiac Platinum DAC with 10M Rubidium Atomic Clock

The Zodiac uses a 64 bit clock with very low jitter. This clock is excellent on its own, but for those who require even more precise timing, there is a connection on the rear panel of the DAC for use with the optional 10M Rubidium Atomic Clock, which has a 10MHz clock signal.

The photo of the rear panel shows that it is not wasting any space. On the left is the power supply jack which connects to the Voltkus power supply, and below that is the 10M connector. Analog inputs are coax, while analog outputs have both coax and XLR. Digital inputs are coax, Toslink optical, and XLR (AES). Digital out has two coax and one XLR.


Software must be installed to use the Zodiac. Once installed, you can power on the Zodiac from the software interface as long as the Voltikus power supply is toggled on.

The interface shows headphone impedance selectors, Upsampling (256X) enabling, Analog Input Trim (14 dB to 26 dB), Analog Output Trim (14 dB to 26 dB), and at the bottom, an image of the front panel of the DAC. You can turn the volume dial (additional analog trim), select the input, which in this case, is USB, and Mute the signal. At the top of the interface are two horizontal level meters.

I found that I had to set the analog trim to 14 dB in order to keep the analog output at a level that comsumer preamplifiers are designed for (4 volts). With a trim of 26 dB, the output voltage of the DAC would damage most consumer preamplifiers. All of the bench tests were taken with the 14 dB setting.


When the 10M is powered on, the clock in the DAC chassis uses the 10 MHz signal from the 10M to synchronize the incoming digital music signal.

All in all, the system with the 10M is easy to use, but there are a lot of features that you have to accustom yourself with. Once you know the playing field, all goes well.

A very nice remote control is included. It has a modest slope which makes it lay in my hand comfortably.



The Antelope Audio Zodiac Platinum DAC with 10M Rubidium Atomic Clock In Use

I performed the listening tests using the Zodiac connected to my lab computer with USB output to the Zodiac, a Classé CP-800 preamplifier, Classé CA-M600 monoblock power amplifiers, and MartinLogan CLX electrostatic speakers. Cables were Wireworld. I also used it almost on a daily basis with headphones while I worked at my computer on other tasks.

Through the USB connection, I could play all of my high resolution music files, including 24/192 PCM and DSD128.

One of the most beautiful albums that I acquired recently, was this one, through the 2L website. It is Hymn to the Virgin, produced by 2L. It is available in numerous formats, including 24/192 stereo (FLAC), 24/192 multi-channel (FLAC), DSD128 stereo, and 24/352.8 DXD. I downloaded them all, and my preference is for the 24/192 over the DSD version, but since the DSD files were created from the 24/352.8 PCM master, they are not really DSD. The reason for this is that DSD, being 1 bit rather than 16 bit or 24 bit, is not editable in the 1 bit form. So, it is converted to PCM for editing, then converted back to DSD. One can only guess at how few SACD albums that we have purchased, went through a PCM intermediate for editing, and then were converted back to DSD.

Anyway, the album is gorgeous, and the amount of detail that was audible, from the high resolution bitstream, and the Zodiac DAC, simply astounded me. It was also sweet (like a Class A biased triode) and musical beyond description. There was no audible distortion of any kind.


The album shown below is an old one that I bought decades ago, before CDs, so it was vinyl. It was converted to CD later on, but unfortunately, I gave away the vinyl when CDs became the hot thing. I ripped this one myself, and it is 16/44.1 (WAV). The title is The Buddy Rich Big Band: The New One!

The first track, “Away We Go”, is the best of the bunch. I heard detail through the Zodiac that I had never heard on the vinyl or CD version through my reference system. The pings of Rich’s ride cymbal, for example, are difficult to single out, because the rest of the band is blasting away, and Rich didn’t like to have his kit individually miked for each drum and cymbal. But, it’s all there, using the Zodiac.

Now, I have to say up front here, that the increase in detail was not like 10X more than what I was used to. My reference system is very good. But, it was enough of a difference that I noticed it.


As I mentioned previously, I used the Zodiac on a daily basis, with headphones, and I was continually distracted – but I kept listening anyway – by the amount of detail I could hear in my music directory that I had not been aware of before.

If you didn’t use it for anything but as a headphone amplifier, it would still be worth the price.


The Antelope Audio Zodiac Platinum DAC with 10M Rubidium Atomic Clock On the Bench

I bench tested the Zodiac DAC, with the 10M clock, using digital signals generated by my Audio Precision 2722, with a balanced XLR cable connected to the AES input on the Zodiac. The XLR balanced analog outputs from the DAC were connected to the XLR inputs on the Audio Precision. So, I generated digital signals, decoded them with the Zodiac, and measured the analog results.

First, some 16/44.1 tests. Distortion measurements were within an 80 kHz bandwidth. I set the output on the software interface to 14 dBu, which produced an output of 4 volts, which is ideal for consumer preamplifiers.

At 0 dBFS, a 1 kHz sine wave produced 0.002% THD+N. Excellent results right from the start.


At – 5 dB, distortion rose just a bit, to 0.004%. The second and third harmonics are the same height, nearly at – 100 dB, which is inaudible.


19 kHz and 20 kHz test tones yielded a B-A peak at 1 kHz which lower than – 100 dB. Fantastic! There is also very little evidence of any side peaks around the fundamental test peaks.


IMD was only 0.005%. Looking good! The peaks at 8.8 kHz and 17.7 kHz are spurious noise below audibility.


The measured frequency response was 10 Hz – 20 kHz, – 0.2 dB.


The time domain spectrum (1 kHz sine wave, undithered, at – 90 dB) is shown below. The three voltages defining the signal are clearly evident (one at – 175 µV, one at 0 µV, and one at + 175 µV), with no unusual noise spurs.


Here is an example of the same time domain measurement on a different DAC that has poor performance.


Let’s move now to 24/192 test signals.

At 0 dB, distortion was 0.001%. Notice that the noise floor is lower than with 16/44.1 signals. This is part of the measurement result.


At – 5 dB, distortion remained unchanged.


With 19 kHz and 20 kHz signals, the B-A peak was at – 104 dB, again, inaudible.


IMD, with 24/192 sampling, was 0.002%. All test numbers are lower with 24/192 than with 16/44.1 (I guess high res is here to stay). There appear to be small 7 kHz harmonics at 14 kHz and 21 kHz, but they are well below audibility.


The measured frequency response, with 24/192 kHz sampling, was 10 Hz – 90 kHz, – 3 dB.


The Time Domain test (performed at 24/96 sampling) at – 90 dB yielded a distinct sine wave pattern. This is because there are many more samples to create the sine wave from in the DAC. Compare this with the – 90 dB sine wave with 16/44.1 sampling. This is why detail is so much better with higher sampling rates. It’s not the higher frequency response that is the most important result. It’s the better re-creation of the musical signal in the audible band.


Lets’ go deeper, and look at a 1 kHz undithered sine wave at – 102 dB (the test is done in 6-12 dB increments, i.e., 90 dB + 12 dB = 102 dB).

Even at – 102 dB, a distinguishable sine wave is there. This, by the way, is the first time anyone has shown such data (time domain tests with 24 bit samples, at lower levels than – 90 dB) in a consumer A/V publication.


Well, why not go even lower? Here it is at – 114 dB, and the sine wave is still distinguishable. However, this, I found, was the limit. If I went lower, the sine wave disappeared into noise. So, you are seeing an actual resolved sine wave at – 114 dB. Incredible. The Zodiac is some piece of DAC!




Conclusions about the Antelope Audio Zodiac Platinum DAC with 10M Rubidium Atomic Clock

This is the first ultra-high end DAC I have tested, and it has been a pleasure. It adds some of that last 5% of sound quality that all audiophiles dream of. It’s expensive, and it’s an extra component to put in the signal chain, but if that’s what it takes, do it.