by Roy Harris
At the 2008 CES, I visited the ESS Technology room and I heard a demonstration of the Sabre 24 bit DAC chip. I was eager to review this chip after a brief listening session which included several of my reference CDs. I contacted the company to obtain a review sample, i.e., a DAC containing the Sabre chip but I did not receive the product from the company, during 2008. I received a called from a PR company in December of 2008, and was invited to visit the ESS Technology room at the 2009 CES for the introduction of a 32 bit Sabre DAC chip and was also offered an opportunity to review the Sabre DAC chip after January of 2009. I indicated that I would not attend the 2009 CES but expressed my interest to review the DAC chip.
Since it is not possible to review a DAC chip by itself, the subject of the review is an evaluation DAC, which includes the 32 bit Sabre DAC chip. The evaluation DAC is offered to engineers and other prospective purchasers of DAC chips to assess the performance of the chip. There is one company, Twisted Pear Audio which offers a DAC, named the Buffalo Dac, incorporating the 32 bit Sabre DAC chip. Their website is www.twistedpearaudio.com. Currently, Samsung, Krell, McIntosh and Peach Tree Audio use the 24 bit Sabre DAC chip in some of their digital products. Visit the ESS Technology website for more information about the company and the DAC chip.
The Sabre DAC chip is the ES 9018, 8 channel, 4 DACs/channel, with upsampling to 864 khz. There are 3 analog devices model AD 797 op amps per channel. The power supply is a Digikey rectangular linear power supply. Digital inputs include USB and SPDIF. Outputs are single ended and balanced. Signal connectors are nickel- plated brass and ground connectors are tin-plated brass. Data conversion is hyperstream rather than sigma delta. The Dac chip can tolerate a wide range of jitter from digital cables and transports, as jitter has been reduced to levels which are virtually inaudible.
The DAC chip is capable of the highest resolution , in all aspects of expression. In addition, the frequency response was balanced, as I did not notice any significant peaks or dips within the frequency spectrum.
I try to introduce one new source, at each review. In addition to Holly Cole, Bream and Williams, Sophie Yates and Arthur Fiedler, I included the music of Theolonious Monk.
Consider, the recording, Theolonious Monk, GENIUS OF MODERN MUSIC, VOL 2, Bluenote CDP 7 81511., track one. Upon first listening, I perceived a layer of dirt having been removed from a window. The sound of instruments were free of timbral errors. Hence, it was easy to recognize the (material) content of Milt Jackson’s mallets, namely wood. It seemed obvious to me as well, that a professional pianist would be able to identify the source of Monk’s piano with out any difficulty. Listening to another track from this disc, reinforced my impression of accuracy of timbre. I focused upon the saxophones.Differences between tenor and alto sax were apparent. As a result, I was confident in my recognition of each instrument.
The second selection was a guitar duet featuring Julian Bream and John Williams, from the CD, TOGETHER, track one, RCA 09026-61450. Julian Bream was positioned on the left, while John Williams was on the opposite side. The observed spacing between the musicians enabled one, to note the timbral differences between the two guitars. The sense of space did not seem to be contrived or artificial, but rather reminded me of a live performance.
Stereo systems can benefit from a periodic stress test as part of an overall assessment paradigm. A suitable source for this purpose is Holly Cole, DON’T SMOKE IN BED, track 1, Alert Z2 81020. Hearing an acoustic bass at the beginning of the track provided some evidence of the neutral nature of the DAC, in that there was a balance between the articulation of the strings and the vibrating wood body. Holly Cole’s enunciation of consonants strongly suggested close microphone placement. While sibilance was noted, it was neither exaggerated nor obscured. It’s quality and quantity were consistent with the affect of close microphone placement upon the sound of a female voice.
At this stage in the review, I desired to test for the presence of a sonic signature. As a consequence, I replaced the GE 6sn7 tubes with a pair of Sylvania 6sn7s in the line section of my preamp. I also reversed the polarity of the speaker cables.
The first test was an orchestral CD, Offenbach, “Gaite Parisienne”, conducted by Arthur Fiedler, track 1, XRCD 0224. The string section sounded less focused and more rounded in character than I would expect based upon previous experience. The woodblock was positioned near the wall , while the triangle was located somewhat behind the right speaker. The shimmer of the triangle was slightly defocused and the treble frequencies seemed slightly attenuated..
The last selection , FANDANGO – SCARLATTI IN IBERIA, track 1, Chandos 0635, features Sophie Yates, harpsichord. The perspective of the instrument was that of mid to rear hall. Hence, the percussive quality of the instrument was somewhat deemphasized. Yet the characteristic timbre was easily recognizable. In addition, there was a softening of the lower treble and a slight reduction in SPL of treble harmonics.
The 32 bit Sabre DAC possesses the attributes of low noise, inaudible jitter, balanced frequency response and neutrality. However, these attributes may be obscured in certain circumstances. For example, after I changed the tubes in my preamp and reversed speaker cable polarity, I noticed a change in presentation. The high resolution and spaciousness I had noticed were no longer apparent. The DAC’s neutrality allowed a sonic signature of the stereo system, created by the aforementioned changes, to be revealed. Resolution decreased, there was a slight loss of focus and a softening/attenuation in treble response. Thus, the DAC acts as a catalyst to highlight the sonic signature, or lack of one, intrinsic to the other components of a stereo system. If you have voiced your stereo system, excluding your digital hardware, to your satisfaction, introducing this DAC will not affect the sound of the other components.
The sound of this DAC may be improved by replacing the Analog Devices op-amps, connectors, capacitors and hard-wired power cord.
Finally, another possible benefit of using this DAC in a stereo system is listening to poorly recorded discs without running out of your listening room. Many recordings are perceived as of poor recording quality. Listening to such discs may be an unpleasant experience. Actually, there are two variables in play, namely, recording quality and quality of digital hardware. Using the Sabre DAC may eliminate hardware-based distortions and render listening to “problem” discs less problematic.
CD Player: Vincent CD S6
Preamp: Mapletree Ultra 4A SE
Amplifier: VTL Deluxe 120
Speaker: Magnepan 1.6, Quad 57
Interconnect: Aural Thrills gold, Homemade hybrid Mundorf gold and Synergistic Research
Speaker Cable: Ear to Ear
AC Cords: Soundstring, Ear to Ear, Clarity Audio, Distech, Element Cable
Power Conditioning: PS Audio P 300, PS Audio Noise Harvesters,PS Audio Juice
Bar, Chang, Iso 6400, Nirvana Audio isolation transformer, IDOS, Bob Young line filter
Anti Resonant Devices: Room Tunes, Corner Tunes, egg crate mattresses, Sound Fusion Sound Boosters, Enacom filters, PS Audio Noise Harvesters
Manufactured by ESS Technology
48401 Fremont Blvd.
Fremont, CA 94538
Telephone (510) 492-1088
Fax (510) 492-1098
ESS Technology website
Source: manufacturer loan