Introducing the new Merason DAC1 Mk II D/A Converter. Over a year’s time was spent carefully considering how to improve upon our award-winning design to offer customers around the world even greater musical enjoyment, and we could not be happier with the results which are described below.
New Design
The structure and routing layout of the PCB was entirely re-designed resulting in a significantly reduced impedance and loss-free power supply delivery to each individual component. In addition, the shielding against external interference was also greatly improved.
New Components
High precision SMD components are now predominantly used throughout the design due to their superior performance characteristics. Unlike the THT parts previously used, the SMD components offer a far shorter component to conductor path resulting in much lower losses. The capacitors in both low-pass filters now have a dielectric made of polystyrene, a material well proven
for high performance audio applications.
New Thermal Concept
New in the Merason DAC1 Mk II is a sophisticated mounting procedure of the power transistors to their individual heat sinks using custom designed disc springs. This intricate method allows for a precisely defined contact pressure, achieving optimal temperature equalization of the paired transistors. This application has dramatically reduced harmonic distortion in the signal path.
The Result
All these measures have led to an even wider and deeper sound stage. The dynamics are clearly greater, with the transient speed and attack reminiscent of live music. Although the measured output level has remained identical, one has the impression that the Merason DAC1 Mk II plays louder with a much quieter background. Micro/Macro details are resolved more distinctly, with new details emerging from familiar recordings that were not previously recognizable. The sound image has become even airier and lighter, with bass now much more weighted and defined. All in all, a converter that plays in a higher league!!
DUAL MONO MODE
Because of their special architecture, but ultimately from a purely sonic point of view, Daniel Frauchiger decided on two Burr-Brown PCM1794-A converter chips. In mono mode, the DAC uses one for each stereo channel. In this way, the PCM1794A has a dynamic range of 132 decibels. That is five decibels more than a stereo circuit with just one component.
DISCRETE CLASS A CURRENT OUTPUT
Since the PCM1794A has a current output, the current signal is converted into a voltage signal. This is not done using operational amplifiers, but rather in a complex, discrete structure. The voltage signal obtained in this way is buffered in the output stage using Class A technology and is present at the XLR output sockets as a symmetrical output signal and at the Cinch sockets as an asymmetrical output signal.
FULLY SYMMETRICAL SIGNAL OUTPUT PATH
The analog signal processing is consistently symmetrical from the converter module to the output. Low-pass filters with high-quality, expensive silver mica capacitors and coupling capacitors are located between the converter module and the output as a safety measure against unwanted DC voltage. Great attention was paid to the layout of the motherboard so that the extraordinarily high signal-to-noise ratio could be achieved.
SEPARATE MULTIPLE POWER SUPPLY RAILS
A separate, generously dimensioned transformer is responsible for the digital circuit. The rectified voltage is regulated to 5 volt rails, and independent 3.3 volt rails. Each functional unit has its own power supply, and in total there are twelve of them. The analog circuit is fed by the second transformer.
The controller is discreet and is characterized by an extremely low interference voltage.
HIGH QUALITY INPUT INTERFACES
The USB input is realized with a high quality board from Amanero, the Combo 384, a board known for its musicality.
The Amanero board has two precise oscillators, one for the multiples of 44.1 kilohertz, one for the multiples of 48 kilohertz. It provides a cleanly clocked I2S signal with minimal jitter at the output.
The I2S signal is sent to the two converter chips in a galvanically isolated manner using a capacitive isolator module.
The signals arriving at the AES and S / PDIF sockets are galvanically isolated by a transformer. The clock of these signals and that of the Toslink signal is refreshed by the receiver module, a WM8804 from Wolfson or Cirrus Logic, using a quartz module and PLL, so that the jitter is also minimized here, and then passed on to the converter modules as an I2S signal.
