Black EX DAC/Control Preamp
The Black EX DAC/Control Preamplifier is designed in a custom plated high-grade aluminum chassis that contains the highest-level DAC performance and source compatibility, including MQA, Roon, DSD, and an internal programmable phono stage. The EX DAC controls input selection, volume control, and manages all source formats with the highest quality detail and musicality from any source ensuring years of musical enjoyment.
The EX DAC/Control Preamplifier is built around our High Dynamic Resolution HDR-II core and high-speed Asynchronous Multi-Input Processor (AMiP) platform that defines the most versatile DAC preamplifier. Stream music through Ethernet or USB, a full suite of digital inputs, line level inputs, sub output and software controlled internal MM/MC analog phono stage.
The EX DAC is designed to manage the complexity of all audio source and control functions with ease and efficiency. The 32-bit volume and multi-processor system functions are controlled by manually pressing and rotating the control dial on the front of the unit, or by using the IR custom remote control, or with your iPhone/iPad and the custom iOS app. The fully programmable display is easy to read and illuminates system status indicating source and volume.
All source inputs are asynchronously re-clocked into the fully balanced advanced segment DAC measuring below 0.001% distortion and 126dB of dynamic range. By stripping away the source clock and using Bel Canto’s custom ULN master clock circuitry, we significantly reduce both jitter and distortion preserving the delicate audio signals from all sources.
Asynchronous ethernet connects you to the most compelling and power musical source available today. Bel Canto’s proprietary asynchronous ethernet and USB-A inputs provide the highest level of performance for high resolution files up to 24bits at 192ks/s, MQA, and DSD64. This allows you to connect to a variety of subscription streaming service or source from your personal library that is stored on a NAS (networked attached storage) drive, or a multi-terabyte independent drive to the USB-A all providing full server function with complete iOS wireless control using our SEEK control App.
MQA (Master Quality Authenticated) is an award-winning British technology that delivers the sound of the original master recording. The master MQA file is fully authenticated and is small enough to stream or download. Visit mqa.co.uk for more information. The MQA logo is a trade mark of MQA Limited. © MQA Limited 2017
RS232 is designed to support easy integration with sophisticated whole house control systems.
The MM/MC phono section is a low noise, low distortion circuit that is fully programmable for optimum application with wide range of quality cartridges from high output MM 2.5mV to 5mV to low output MC 0.25mV to 0.5mV to optimized performance.
The line level analog input also can be programmed to gain match your analog sources and achieve the best performance from all analog sources. The line output can be connected to a powered subwoofer.
The front mounted headphone jack opens up high quality sound for your favorite headphones. Plug in your headphones and the EX DAC configures itself into a superb headphone amplifier with a high performance buffer stage that can drive down to 32 ohm. Control the output level using the main control, allowing you to select the headphone or main speaker output while leaving the headphones in place.
Digital Done Right
aci-tech2The HDR-II Core digital design starts with our Ultra-Low Phase Noise Master Clocks. These superior clocks are free running and fed from dedicated ultra-low noise analog power supply regulators. There are 2 stages of asynchronous interfacing to ensure that the final DAC output is jitter free and independent from any noise on the incoming digital signals. Our custom MQA based digital filters define an optimized impulse response from all sources, MQA, PCM, Analog and DSD. Figure 3 shows this impulse response with a 44.1kHz CD test signal. Our custom digital filters are designed to largely mimic the time domain response of an audio signal traveling through 10 meters of air. This superior time domain response insures the best sonic performance for all signals reproduced by our HDR-II Core DAC technology. MQA, High Bit Rate PCM, Analog and DSD all approach the impulse response resulting from travel through 10 meters of air, retaining the critical time relationships in the original music.
Pure Class A Differential Analog Output
A critical advantage of our HDR-II Core architecture is how the Class A Differential Current Mode output from our DAC operates in concert with our custom balanced analog section to best preserve the original dynamics of the recording. The large constant-bias differential currents impose pure Class A operation to every part of the analog output stages, every precision resistor, film capacitor and amplification device is biased with constant current and voltage. This constant bias keeps all components in thermal stasis and insures that all the original signal dynamics are retained.
Our proprietary SSHA (Single Stage High-Current Amplifier) interposer module is used in the Black HDR-II and Black EX DAC Core design. This is a very fast, low noise amplifier with a single-stage folded cascode architecture and over 500mA of peak current output capability. It maintains constant very low distortion levels through the audio band because of its high open-loop bandwidth. The SSHA module brings a further element of dynamic resolution and contrast to the HDR-II Core. The vertical modular design permits a tight, efficient Printed Circuit Board (PCB) layout that combines the best of IC based and discrete component design. The PCB represents a final degree of design refinement that is especially critical when the circuit is capable of 130dB of dynamic range or more.
Through careful parts choices, architectural considerations and design details, refined over numerous generations, Bel Canto’s HDR-II Core has been optimized to render pure, dynamic analog signal quality from all music sources.
Phono
Our dual stage phono architecture is used in the ACI 600. It consists of an Ultra-Low noise input RIAA amplifier with precision filter components and fixed 40dB gain. This is followed by a digitally controlled analog variable gain stage to adapt the RIAA gain for a broad range of MM and MC cartridges. Input loading is controlled from the menu so that you can load your MC cartridge with the optimum impedance. This new Phono Architecture is optimized for accurate, low noise RIAA filter operation and compatibility with many cartridges.
Headphone Output
The Headphone output is driven from a dedicated 112dB dynamic range DAC through a high current output buffer stage. It can drive 32-ohm phones to high level and provide excellent headphone sonic detail and performance.
Sub Output
Bass Management functions include independent selection of a 2nd order Butterworth Low Pass and High Pass filter set. The main speakers can be run full range or rolled off below frequencies from 40 to 120 Hz. The Subwoofer Low Pass can be set for full range or frequencies from 40 to 120 Hz. This approach drives maximum flexibility to optimize the integration of a subwoofer. There is also +/-6dB of gain trim range on the subwoofer output.
Line Level Inputs
There are 2-line level analog inputs that provide 110dB of dynamic range and can be used for legacy analog sources such as tape, tuner or a Home Theater bypass where the volume level would be set to a high setting (84.0) on the ACI 600 and volume is controlled through the Home Theater processor. These inputs enhance the ability to integrate the ACI 600 into many different systems with many different signal sources.
Technical Specifications
Maximum Data Input Rates:
24bit Data to 192ks/s: AES, SPDIF, TOSLINK
24bit Data to 192ks/s, MQA, and DSD64: 10/100 Ethernet
24bits to 384ks/s, MQA, and DSD64/128 (DoP): USB2 Audio
Low Level Outputs:
Line Level Analog: 4.5Vrms with Bass Management
Headphone: 4.5Vrms maximum, 32ohm minimum load
MM/MC Input:
Input Sensitivity: MM: 2.5mV to 5mV; MC: 0.25mV to 0.5mV
Input Load: MM: 47K ohms; MC: 50, 100, 500, 1000
RIAA Accuracy: +/- 0.25dB, 50Hz-15kHz
THD+N: < 0.01% 1kHz A-Weighted
SNR: > 70dB A-Weighted
Line Inputs:
Maximum Input: 2.2 Vrms RCA
Input Impedance: 10k ohms RCA
THD+N: 0.003%, 1kHz
Dynamic Range: 110dB, A-weighted 20Hz-20kHz
Main Outputs:
Balanced XLR Output and Impedance: 5.5Vrms, 100 ohms
RCA Output and Impedance: 2.75Vrms, 100 ohms
Performance:
Dynamic Range: 127dB A-weighted
THD+N: < 0.001% 1W, 1kHz, 4 ohms
IMD (CCIF): < 0.001%, 1W, 18.5:19.5kHz 1:1, 4 ohms
General:
Power Usage On: 20W
Power Usage Off: 0W
Internally Set Operating Voltages: 100-120VAC, 220-240VAC 50/60 Hz
Dimensions: 17.75 W x 15.5 D x 3.5 H inches, 451 x 394 x 89mm
Weight: 25lbs. (12 kg)