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This is the 43rd in a series of reviews dedicated to the concept of 32Ohm Audio as embodied by the store of that name in downtown Portland/Oregon and described here - Ed.


Reviewer: Srajan Ebaen
Financial Interests: click here
Source: 27" iMac with 3.4GHz quad-core Intel Core i7, 16GB 1.333MHz RAM, 2TB hard disc, 256GB SSD drive, ADM Radeon HD 6970M with 2GB of GDDR5 memory, PureMusic 1.82 in hybrid memory play with pre-allocated RAM and AIFF files up to 24/192; Metrum Acoustics NOS Mini DAC Octave; Antelope Audio Zodiac Gold/Voltikus, Burson Audio DA-160 [on review], April Music Eximus DP1 and Stello U3 [in for review]
Preamp/Integrated: ModWright LS-100 with Synergy Hifi tubes, Esoteric C-03, Bent Audio Tap-X
Amplifier: FirstWatt F5 and SIT proto [on review]
Speakers: Aries Cerat Gladius [on loan]
Cables: Complete loom of Zu Audio Event, Entreq USB cables
Stands: 2 x ASI HeartSong 3-tier, 2 x ASI HeartSong amp stand
Powerline conditioning: 1 x GigaWatt PF2, 1 x Furutech RTP-6
Sundry accessories: Extensive use of Acoustic System Resonators, noise filters and phase inverters
Room size: 5m x 11.5m W x D, 2.6m ceiling with exposed wooden cross beams every 60cm, plaster over brick walls, suspended wood floor with Tatami-type throw rugs. The listening space opens into the second storey via a staircase and the kitchen/dining room are behind the main listening chair. The latter is thus positioned in the middle of this open floor plan without the usual nearby back wall.
Review component retail: $795
AdaptiWave™ and the two-stage JitterGuard™ from Chicago pro audio firm CEntrance have crossed paths with 'philes inside kit from Bel Canto Design, Benchmark Media, Empirical Audio and Lavry. Those companies have licensed this adaptive technology written to a TAS 1020B USB controller.


While asynchronous USB is the buzz word du jour in computer audio converters, gear from these firms has garnered positive reviews which were accompanied by truly excellent jitter rejection measurements. Now comes the CEntrance DACmini from the firmware algorithm's actual authors. The photo tells all there is to tell on the machine's functionality. It's a 4-input relay-switched DAC, preamp with one analog input* plus headphone amplifier. Shape and dimensions duplicate the iconic MacMini. The 192kHz figure applies to both coax and Toslink, not USB. That's limited to 96kHz.
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* The analog input is compatible with up to 15V signals to be essentially unclippable.

This converter can run off a variety of power supplies to support pro applications where just the right PSU isn't always on hand but the show must go on. Wart power between +9 to +19V DC then supplies juice to a custom-made switch mode transformer-isolated power supply which in turn generates ultra-clean ground-isolated independent +/-15V supplies for the analog circuitry, +5V and +3.3V for the digital circuitry and a separate clean +5V analog supply for the D/A converter. A full 30V of power are available for analog circuitry to lower noise and reduce distortion.

Internal SMPS removed

Inside the chassis, each PCB is firmly secured inside its individual cavity. All PCBs are attached to extruded threaded bosses via industrial-grade 3mm screws for drop-proof reliability. Gold-plated connector blocks and ribbon cables join PCBs together electrically, making assembly and service easy and quick.


The internal layout is digital to the right, analog to the left and never the twain do cross electrically. Instead the signal crosses the analog/digital divide on the 4-layer board over a magnetic barrier. That also explains why the USB input is on the right and the headphone and analog outputs on the left. The RCA connectors are isolated from the chassis by plastic washers to avoid ground contact and the entire signal path is DC coupled, hence capacitor free.


Irreversible mod options include scratch-resistant black anodizing for the stock silver enclosure; conversion of the 10Ω headphone output impedance to 1Ω for low-impedance loads; increasing the stock gain of 8 on the headphone port to "rock'n'roll" strength; and variable analog outputs (the stock output is fixed to require a preamp, integrated amp or powered speakers with their own attenuator).


For specollagen injections, CEntrance offers a 10ppm clock with "immeasurable" jitter; +6dBV line output; -144dB S/N and -128dB crosstalk on the line inputs; 25Ω output impedance; and 1.5-watt class A DC-coupled headphone power for 32 - 600Ω loads (max +13.5dBV into 32Ω, +18.6dBV into 300Ω and +19dBV into 600Ω). Dimensions are the Apple-ish 164 x 164 x 42mm. Weight is 1.7kg.


On the identity of their chosen DAC chip, circuit architect and managing director Michael Goodman only confirms that "CEntrance is the official design firm for Texas Instruments, Analog Devices, Oxford Semiconductor, XMOS Semiconductor and many other IC vendors to have early access to all their chips". For the rest of it, he'd rather have you listen with your ears. Don't pay heed to uninformed but rampant forum opinions on what various chips sound like. They cannot be evaluated in isolation from accompanying circuitry. One cannot extricate parts from overall implementation. Unless one is the designer. Mum is the word on silicon then. Officially.
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