This week I've had a pleasure to host Larry Gullman and his wife Linda from MSB. Larry brought along MSB's flagship DAC for listening and I was really surprised with its potency. Here is sum up from our conversations across few days regarding the Select DAC...
Select DAC started as a battle of the Opamp. Larry wanted to explore ability to drive power amplifiers directly without the Opamps and that led to the prolonged researched. After all calculations and explorations they did the math and concluded that 8 DAC’s per channel would provide enough gain, that could server the variety of power amplifiers directly with no output drivers, output stage or opamps involved with the output stage.
After years of R & D they MSB team was ready to start the all new challenging project with completely new proprietary architecture. There were many high expectations and with the rising demand of DSD this was a mandatory addition. MSB engineers went back to the drawing board and put their efforts into developing new and unique hybrid DAC module that was dynamically reconfigurable to do the best possible job with DSD and do the best possible job with PCM. There is no compromise with ether music format andDSD module integrates directly within the Select ECO system.
After developing ground base for the Select DAC next step was materialization of the DAC running on the lowest possible jitter. This was not easy task and everything needed to be revisioned and upgraded. New DSPs with faster speeds were implemented and the select DAC was treated from the ground up as RF device rather then typical DAC. MSB forward thinking was always about refining all the little details and creating a seamless synergy between all parts and modules. By cleansing up the menus and simplifying the operations in Select DAC it was possible to finally focus on cleanest and simplest possible signal path.
New input modules offered much better isolation and pushed the performance of each format. The module format also makes the DAC future proof. Each of this modules has I2S connector and only one module is active at the time. By rediscovering some of the old technologies and adding some new approaches MSB moved few steps further.
Select sports two power inputs for both the analog and digital sides. Power supply comes in dedicated chassis and this can be upgraded with additional mono power supply for even greater performance.
As Select DAC is completely modular, output modules can be both balanced or single ended. All of the modules are interchangeable and can be optimized to work in the best possible way. Larry’s philosophy always follows the simplistic, yet highly refined approach avoiding the unnecessarily features being there just for sake of it.
For example, stepping further into the realms of complex digital audio world… Every DAC on the market comes with SPDIF receiver with its own clock. This adds it's additional noise and jitter to the internal clock and in most of the DACs clock is usually running all the time, producing amount of noise and jitter that shouldn’t really be there. Which brings us to the hearth of the matter…
Femto 32 is the MSB’s lowest jitter clock and one of the brand's most important breakthroughs. Effect of the jitter is directly connected with the clarity and harshness and one can heart the difference instantly. Most interestingly and intriguingly, the refinement of the Femto32 clock resulted with a sudden change of gain level. On the white paper this shouldn't happen, but the lower phase noise gave to the ear the effect of sounding 2 db quieter. The lower jitter resulted in the extended headroom, dynamic range and most importantly in the absence of the listening fatigue that affects directly un-disturbed listening.
There are a lot of confusions regarding the clock and jitter. It's hard to understand the real science and tech behind with every company claiming of manufacturing their Femto clock. In reality most of them are just using the Femto clock designed for some other application and different industry.
MSB clock is actually running on audio frequency and not on 10 mhz (rubidium clock etc.) as the clocks designed for satellites and other equipment. There are two clocks being active and running on t the correct multiple of 44 and 48 kHz, namely at 22.5792 and 24.576 MHz.
On the upper plane of state of the art digital audio second biggest requirement is the integration of the clock with the DAC. This usually introduces many other problems and timing wise one femto seconds at the starting path morphs into one pico second once it reaches the DAC, consequently showing not so little audible shift in the performance.
Those two principles mentioned above eliminates 90 percent of the typical industry claims. MSB was the first company that manufactured Femto second clock and its the company best kept secret. MSB was also first company that embraced discrete sign magnitude ladder DAC back in 2000.
Larry and team wanted to create a power conditioner that would be compatible with multitude of power amplifiers in any given situation. They explored idea further then most and failed, always finding a trade off between clarity and dynamics and base response. They concluded that if they cannot fix the noise, why not making it irrelevant. If the amplifier has the the same attributed noise imprint as DAC then the only important focus point should be the signal. Following that logic, ground shield of transformer should be connected directly to the chassis and disconnected from the wall outlet. As the DAC ground shares the exact same propensities as amplifier, by using inverse process, they actually cancel out each other.
In that way dedicated ground wire is pulling the noise from the power amplifier and helping in cancelling noise out. Dedicated ground boxes that are trendy these days are doing the same thing but in a much more clumsy way. Grounding wise default this isolates Select DAC from the the rest of the world by far.
Along the way MSB engineers realized that any additional isolation just pushes things further and leads to additional finer adjustments. They tried to engage similar principles where applicable in best possible way.
WHY LADDER DAC?
Envision the task of transferring the flow of the water. There are two ways to conway such flow in digital world. Delta Sigma acts like a little measuring cup distributing the water. There is huge amount of the water needed to be transferred via the cups and such endeavors is always under or over shooting.
On the other side ladder DAC comes with whole range of measuring cups ready to be used at any time. You can decided which size of the jugs is right for certain momentum. Standard ladder DACs by default always fills jugs starting empty, at the place where music is at full level, but with sign magnitude ladder DAC you start half full, at the place were music is quiet can adjust the transfer of the water and chose appropriate jug. Thins analogy-process can be very accurate for each bit and at any time largest cups can be used when larger energy flow transfer is needed. For example with the large Kodo drum. At such occasion bigger jug can transmit needed energy in much more optimized way then other processes.
In theory this translates to analog like process that is instantly adaptable, reacting more on the level of minute change of the music’s pace, rhythm and speed, rather then working constantly with the larger frequent flow of smaller package transfers.
Delta sigma is by nature fast switching device. If you don't filtered it's just a multiple processing hash. On the other side ladder DAC operates at voltage change and it doesn't require any type of filtering, translating to much more vivid and fluent rendition of the music. See link for details here.
Ladder DACs requires a precise resistor to be accurate. That why makes it much more expensive solution and the sole reason why Phillips moved away from ladder DACs.
This should cover the first insight into the MSB Select DAC. Much more is coming in the upcoming exclusive interview with Larry.
There is a lot of philosophizing in the digital audio world with very little practical sonic results. Sadly even with some if not most old “players”. For Larry the most important thing is factuality and real world accomplishing of the elaborated and contemplated ideas. Without objectifying and materialization of even most wildest ideas and out of the box thinking all seems like a dream. MSB Select DAC sonic rendition feels like waking from lucid dream and experiencing the reality. Impact still lingers on with me and I’m more then happy when my preconceptions are being smashed by both technical elaboration and sound performance. Both Larry and MSB Select DAC surprised the heck out of me and caught me off guard and yes, this really happens rarely these days…
Select DAC review is coming up in due time. And, yes this belong to the utmost highlights of the year.
Text: Matej Isak