Young and still not too recognizable brand MyST was organized by American company Mycroft in 2010. Under the brand MyST produced portable amplifiers and DACs, in 2012, the company released a line of in-ear headphones armature Nail, but this will not stop there. The first MyST product was the DAC 1866OCU headphone amplifier/dAC in one housing and this review is dedicated to it. Only we tested an improved version of the DAC 1866OCU v2.
CONSTRUCTION
The device has a small aluminum housing. On the front there is a power tumbler, two headphone jacks with original Neutrik connectors, input indicators and knob-button, which can adjust the volume and rewind the inputs of the device. On the back panel we see the power connector, the line stereo output from the digital-to-analog converter, and three digital inputs: USB, optical and coaxial. All RCA connectors are original Neutrik.
The vast majority of modern converters use so called delta-sigma chips with data oversampling and noise generation. Inexpensive and with impressive performance on elementary signals, they have almost completely squeezed other converter implementations out of the market. MyST DAC 1866OCU v2 â one of the few white crows in this flock. Contrary to fashion the device is equipped with multibit converter, which uses âancientâ, direct and ideologically clear method of parallel digital-to-analog conversion by means of R-2R resistor âladder.
The conversion is not done by processing a 1-bit sequence followed by data interpolation, as in delta-sigma chips, the data is converted in whole words. A resistor matrix consisting of several stages, the number of which corresponds to the digit capacity of the converter, is attached to the register of the multibit DAC.
In the âladderâ the resistance of each new step is exactly half of the previous one, setting the âweightâ of the bits. Accordingly, each successive data digit âproducesâ twice as much current and so on, until the end of the register. The advantages of the method are the elegant simplicity of the circuit and the highest potential accuracy, lower jitter sensitivity and absence of high-frequency noise, compared to delta-sigma converters. It is believed that multibit DACs are better at conveying amplitude variations in sound, l
The high sensitivity, dB/mW are able to reconstruct the complex wave packets encountered in the real musical signal.
On the other hand, the circuit is always more cumbersome and the linearity of the converter strongly depends on the accuracy of resistor sampling for the âladderâ, at least laser processing of resistors has to be used. As a result, it is impossible to make a quality multibit DAC cheap, and thatâs why multibits are found less and less often in the industry today, remaining only in the High-End and DIY categories.
When it comes to audiophile converters on multibits, most often they mention circuits on the legendary PCM1704 chip capable of supporting bit depth and sampling of modern HD sound formats. The MyST converter uses an easier chip â AD1866RZ 16 bit/44,1 kHz , not suited to âhigh definitionâ content. In the DAC MyST digital âenhancersâ are absent, expanding the dynamic range and frequency range of the signal and are required in order to somehow filter out the noise of delta-sigma converters.
Itâs no secret that the use of upsampling digital filters can have a detrimental effect on the soundâs transient response, negating all the benefits of the multibit approach. Therefore, the DAC MyST is made by the NOS-scheme No Over Sampling without any recalculation of bit depth or sampling rate. Unlike the SPDIF converter, the USB DAC of the device is quite ordinary and based on the PCM2704 chip 16 bit/48 kHz .
Letâs talk briefly about other features of the device. The power supply has two 8-watt toroidal transformers made by Tver-tor-trans: one for digital circuits, the other for the analog tract. Specialized ELNA for Audio capacitors are used for buffering â 4 pieces of 4700 ÎŒF. The output cascade of headphone amplifier is assembled on complementary pairs of silicon bipolar transistors KT818g/KT819g one pair per channel , providing impressive voltage swing of 30 Volt.
The manufacturer promises trouble-free operation of the amplifier with any headphones, which impedance varies from 8 to 600 Ohm. Another advantage of the device is a very precise digital volume control designed by Alexey Nikitin 128 positions with 1 dB step , performed with seven fast-acting relays.
SOUND
DAC and headphone amplifier DAC 1866OCU v2 doesnât belong to those devices, which strike the imagination with partition nuances, image holography or bass hyperdrive, enticing listener with some unusual accents and angles, which make familiar records sound in a new way.
The main features of MyST tandem are invariably smooth balance, musicality and comfort of reproduction. At first this unobtrusive, smooth-sounding manner does not take your breath away, you have to pay close attention to it. But the more you listen, the more you like the sound. You begin to enjoy the gift of pulling the musical harmony out of the most different phonograms, even the ones recorded not too well.
But letâs move on from lyrics and general impressions to specifics. Surrounded, slightly forward stage with nicely focused solos. The performers are surrounded by beautiful, transparent halos. In large compositions the images may slightly overlap each other, but acoustically the separation of the instruments is confident even on the tutti. Itâs hard not to note the natural timbres and richness of the overtonal palette of sounds, every instrument is beautifully prescribed and 100% recognizable, vocals are perfectly outlined in the composition and emotional.
There are no unnatural qualities like harshness, underlining sibilance or ripples in sound transitions. The dynamics can be called sound of good quality, though at the ends of the spectrum the articulation can be better, hence a certain softness of the sound. So MyST is definitely good for any acoustic music, jazz, classical, especially chamber forms, smooth electronics. His way of performing energetic music probably wonât inspire everyone.
USB-converter, in principle, retains a nice sound signature of SPDIF DAC part, but it does not avoid traditional for this interface limitations: a smaller scale of the musical space and resolution of details.
PRICE: 39 000 Dollars.
SUMMARY
MyST DAC 1866OCU v2 gives you smooth, harmonious and musically authentic sound. Of the limitations of the device, we note the slight lack of energy and the inability to play HD-formats of sound.
What are the specific features or technology used in the MyST DAC 1866OCU v2 that contribute to its voluminous sound and excellent focus on solo images?