exaSound Audio Design e32 DAC
Input: Asynchronous USB Audio 2.0: PCM Up to 384 kHz; DSD 64 Fs: 2.8224 MHz; 3.072 MHz, DSD 128 Fs: 5.6448 MHz; 6.144 MHz, DSD 256 Fs: 11.2896 MHz; 12.288 MHz
SPDIF Coaxial Input 1: PCM 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz
SPDIF Optical Input 2: PCM 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz
Output: Balanced (XLR), Unbalanced (RCA)
Dimensions (H x W x D): 2.2 inches X 6.5 inches X 9.25 inches
Weight: 2.4 pounds
When I recently heard that exaSound Audio Design had released a new model replacement for their e22 DAC, I immediately contacted George Klissarov, President of exaSound Audio Design, to see if I could get a review sample of the new e32 DAC for an AudioStream review. I was very enthusiastic about the e32’s predecessor when I reviewed the e22 in 2014. At that time, I found the e22 to be an excellent sounding DAC and one that did a first-class job playing DSD files. The e22 was built around the ES9018S Sabre32 reference DAC chip and utilized exaSound’s custom ASIO drivers that allowed native DSD256 support for both OSX and Windows.
The new e32 now uses an ES9028PRO Sabre32 reference DAC chip that offers superior performance compared to its successor; the Sabre ES9018S. exaSound retained many of the design features of the e22 including:
- ZeroJitter-a unique asynchronous USB interface with error correction that assures accurate data reception.
- ZeroResolutionLoss- an exclusive volume control with three-way volume synchronization.
- GalvanicInfinity™-complete galvanic isolation for external noise reduction from the computer. Galvanic isolation between the USB subsystem and the DAC circuitry eliminates ground loop noise and blocks computer-generated interference.
- FemtoMaster- exaSound’s quad-clock architecture with 82 femtosecond master clock and 3 auxiliary stream-control clocks.
- A truly balanced design that yields the best analog noise performance and lowest distortion.
- Data is provided from an FPGA core and is stored in the DAC FIFO memory buffer. The FPGA core makes sure that the buffer never becomes empty during playback. Data from the buffer is streamed to the DAC chip. The precision of the timing of the output stream is determined only by the DAC oscillators and is not degraded by the computer clocks or by delays caused by the USB interface.
The e32 DAC is built around the recently released ES9028 DAC chip from ESS Technologies. We’ve been using the old one, the “legendary” ES9018S since 2010. It's been a long wait for the new chip. During the past several years ESS released a couple of modifications of the ES9018 targeting low power consumption for mobile applications and lower cost. The revised editions of ES9018 also fixed issues of the original design and made it easy for DAC manufacturers to support DSD128 and DSD256. Our competitors used them because of the lower price and ease of implementation. Despite the difficulties, we continued to use the original chip because of the superior specifications and ultimately - the superior sound.
Finally we have a superior successor of the ES9018S – the ES 9028 PRO. Notable advancements include quantizer improvement via additional dither, improved dynamics, redesigned mapping of the digital signals to the analog subsystems of the chip and improved noise vs. DC offset.
To bring out the best of the ES 9028 PRO we've redesigned the e32 output stage, the reference voltage sources, the firmware and the drivers for Mac and Windows. We are very excited about the improvements in sonic fidelity and in technical capability. Compared to its predecessor, the e32 has better handling of the top sampling rates - DSD256, DXD and PCM 384kHz. Switching between different formats and different inputs is faster and seamless. The improved exaSound Dashboard provides more convenient remote control of the DAC.
Other features found in the e32 include:
- An external SMPS power supply with 11 power cleaning stages within the DAC. These multiple power cleaning stages allow every circuit to be powered separately with its own stage of power regulation. This feature prevents one power stage from modulating another stage helping to eliminate one source of DAC jitter.
- The availability of a 12 volt, 1.5 amp power supply input for easy substitution of the SMPS with a linear power supply.
- Headphone Output: A third generation headphone amplifier, 4W into 16 ohms, that doubles the current output to drive low impedance and low sensitivity headphones.
- Digital Inputs: USB - This is the recommended input. It supports 2 channels PCM up to 32 bit resolution at standard sampling frequencies from 44.1 kHz to 384 kHz, and DSD from 2.8224 MHz to 12.288 MHz. The 2 S/PDIF inputs provide jitter reduction and D/A conversion when used with CD transports.
- Remote Control: An Apple 7 button remote is provided. exaSound DACs can be user- programmed to work with most infrared remote controls using Sony or NEC IR protcols.
- Trigger Output: When the e32 DAC is on, a 12 VDC signal is sent from the Trigger Output to control other devices. When the e32 is placed in Standby mode, the trigger signal is discontinued.
- Direct Connection to Analogue Power Amplifier: If your music sources are digital, you don't need a preamplifier. The built-in volume control allows analog power amplifiers to be connected directly to the e32 DAC. The e32 DAC volume is controlled by the ES9028 Pro DAC chip allowing volume level changes in steps of 0.5 dB. Volume processing is performed by the DAC chip right at the border between the digital and the analogue domains. exaSound claims that this architecture offers a signal to noise ratio comparable to the best analog volume controls with virtually no loss of digital resolution.
George describes the benefits of ASIO:
- Unlike the computer sound systems ASIO is designed for one purpose - sound fidelity.
- ASIO is light-weight, bit-perfect, allows for automatic sampling rate switching.
- ASIO has native DSD support.
- With ASIO the DAC is the master, and the computer is the slave when it comes to controlling playback timing. The timing accuracy of playback can be as good as the DAC’s master clock.
- ASIO offers better implementation of asynchronous operation than Core Audio and the Windows sound system.
The front panel controls of the e32 are well thought out and easy to use. The Volume Control has UP and Down selectors. There is a Power Switch and Input Selector. The Setup selector is used to program another remote control. The Display shows the input, volume level, number of channels, and file type (PCM or DSD) with sample rate.
Setting the volume to 0dB turns all volume processing off and sets the device in volume bypass mode.
For the evaluation of the e32 I used my Asus G701VI laptop running Windows 10 Pro 64 on one partition, and Windows 10 Pro 64 with the AuiophileOptimizer on a 2nd partition. The Asus G701VI possesses an overclockable Intel Core i7 6820HK processor with 32 GB DDR4 2400Mhz SDRAM and a very fast PCIe Gen3 X4 NVMe SSD. This laptop has 3 USB 3.0 ports as well as a Thunderbolt port (USB type- C). An NVIDIA GeoForce GTX1080 with 8 GB VRAM processes video. This powerful video processor allows significant CUDA offload processing for the HQPlayer. The Asus laptop was plugged into a Shunyata Research Hydra DPC-6 v2 distribution center to firewall the noise generated by this computer from contaminating my AC line.
The Asus was placed on a Synergistic Research Tranquility Base UEF grounded with the Synergistic Research High Definition Ground Cable / Grounding Block as was the computer. A G-Technology 16 TB G|RAID Thunderbolt 2 / USB 3 drive was connected to the Asus with an AudioQuest Coffee Thunderbolt cable. The G|RAID Thunderbolt drive was powered by an HDPlex 100w linear power supply plugged into a Shunyata Denali power conditioner. The G|RAID Thunderbolt drive and its HDPlex power supply were placed on a Synergistic Research Tranquility Base.
Music software used for the evaluation of the e32 included Roon, JRiver Media Center 22, and the Signalyst HQPlayer.
The e32 was placed on a Synergistic Research Tranquility Base UEF and plugged into a Shunyata Triton v2 / Typhon with a Shunyata Alpha Digital AC cord for part of the evaluation. I also listened to the e32 placed directly on my maple wood rack.
I had very good sonic results using a Wireworld Platinum Starlight 7 USB 2.0 cable with the exaSound e32.
Also employed in this evaluation were the HDPlex 100 watt linear power supply and the new Fidelizer Nikola Linear Power Supply.
After rereading my review of the exaSound e22, I was quite surprised with what I was hearing with the new e32. While I had found the older e22 to be somewhat “light” sounding in character, I found the e32 to be quite different. The e32 has richness to the sound that is natural and not overly warm or full sounding. In fact, the basic sound of the e32 reminds me of the “analog type” sound that I have heard in DACs costing far more than the e32. Basic sonic characteristics also included a very well controlled dynamic low end, a wide and deep soundstage, a deep black background, and good detail retrieval in the midrange and high end. The e32 is totally fatigue-free and very musically engaging.
I heard equally good performance with PCM and DSD files. The DAC’s ability to play DSD256 files was exemplary with no drop-outs or other extraneous noises using Roon or JRiver for the software player. The e32 had absolutely no problems moving from different formats or sampling rates. The ASIO driver I used for Windows was rock stable and worked flawlessly with a non-optimized (slimmed) Windows OS. Use with an optimized Windows OS (Audiophile Optimizer) contributed to additional sonic improvements.
I listened to the e32 with both the single end and balanced outputs and found that I preferred the balanced outputs for best sonic performance.
All of the above was heard using the power supply that came with the exaSound. While this is a switch- mode power supply (SMPS), it did sound very good powering the e32.
Linear Power Supplies
The exaSound e32 needs a 12v, 1.5 amp power supply with a male barrel connector. I had 2 linear power supplies on hand that would meet the needs of the exaSound e32; the HDPlex 100 watt LPS and the Fidelizer Nikola LPS. The Fidelizer is a new product that I will be evaluating in a future review.
I did hear a small improvement in the sound with the HDPlex powering the e32 compared to the stock power supply, but the Fidelizer power supply transported the sound quality to another level. The soundstage became larger with better focus of instruments and voices. I also heard better resolution of transient detail from the e32 when powered by the Fidelizer Nikola LPS. Background silence seemed enhanced with the Nikola.
Given the e32’s outstanding performance playing DSD256 files, I decided to see how the HQPlayer would sound upsampling all files to DSD256. I applied the poly-sinc short-mp filter and the DSD 7 256+fs modulator as my settings. I also used Roon to stream to the HQPlayer on my Asus Core computer.
Not surprising to me, I found the sound to be excellent converting all files to DSD256. HQPlayer’s filters and modulators are second to none, at least in my experience. The soundstage was bigger, with even greater natural ease to what I heard in the midrange and high end. This is not to suggest that one needs to listen to the e32 with the HQPlayer to obtain the greatest musical satisfaction- far from it. What I am suggesting is that the e32 has the stability to function in this capacity if the user desires to use the HQPlayer. Naturally, there is no one best choice of filter and modulator for all users, so it truly becomes a quest for audio nirvana when playing with the HQPlayer.
Other Features of the e32
exaSound feels that the volume control of the e32 is more than capable of driving a good amp or set of power amps without a preamp. I connected the e32 directly to my Ayre MX-R Twenty monoblock amps with balanced Synergistic Research Atmosphere Level 4 cables. I have to admit that the overall sound was pretty good and will probably satisfy many users who don’t have a preamp. It should come as no surprise that the volume control in the e32 failed to outperform my $27,500.00 Ayre KX-R Twenty preamp.
The headphone amp in the e32 had no difficulty driving my AudioQuest NightHawk headphones with more than adequate volume and good reproduction of instrumental textures. While it would have been nice to see balanced headphone outputs on the e32, the single end headphone output did sound very good.
The wonderful soundstage capabilities of the e32 were well demonstrated with the 2014 recording of Tchaikovsky: Symphony NO. 6 performed by Ivan Fischer and the Budapest Festival Orchestra. Roon indicated that this DSD64 recording had a dynamic range of 22. And sure enough, be prepared to turn the volume up to fully experience this fine recording. The exaSound e32 was capable of reproducing a richly layered soundstage with a tube-like bloom and dimensionality. The e32 was very capable of resolving low level information with an ultra-quiet background.
If one is interested in hearing purity and liquidity to reproduced sound, one does not have to go any farther than the John Abercrombie Quartet release Up and Coming. This 24/96 recording was harmonically rich allowing the e32 to capture every inflection and nuance of the performance. The e32 can really dig down deep in terms of detail and focus providing a first-class resolution of the sound.
Folk-blues artist Eric Bibb with North Country Far and Danny Thompson’s album The Happiest Man in the World was a real treat when played with the e32. The 24/88.2 recording allowed the e32 to reproduce the string instruments with excellent resolution of transient detail. Eric’s voice was well focused with realistic dynamic life. The entire presentation was relaxed and quite natural sounding when heard through the e32.
Excellent Performance at an Affordable Price
I was very impressed with the level of performance delivered by the new e32 DAC. Given its price of $3499, one is getting a DAC with sonic performance unobtainable several years ago at this price point. For a relatively small amount of money, one can add a good linear power supply to the mix for an additional bump in performance. The e32 has demonstrated how to build a DAC that not only handles PCM files, but DSD files in a first-class manner with custom high performance Mac OS and Windows ASIO drivers. My compliments to George Klissarov and his design team for the superb evolutionary improvements found in the new e32 DAC.