Well for starters Jh901 the top of the line MSB uses their own designed discrete version of R2R Ladder Multibit.
"MSB Sign Magnitude R2R DAC
MSB has always known the ladder was a superior conversion method and introduced the world’s first discrete 24 bit Sign Magnitude R2R Ladder DAC. The term Sign Magnitude describes the special architecture we use that dramatically improves the sound of low level signals. Instead of always starting at the lower limit of the signal and adding voltage to reach the music signal, we start at the midpoint, or zero crossing, where music is quiet, and we either add or subtract voltage to get the required signal. Because this requires a much smaller addition or subtraction on average, it can be done much more accurately.
MSB has designed and built a new proprietary R2R architecture that far exceeds the performance of the original ladder DAC design. The performance of a Ladder DAC is defined by the precision of the resistors. There are hundreds of very expensive aerospace grade resistors on each MSB module producing a DAC with a level of precision that is unheard of. The noise floor (the lowest sound that can reproduced), is much lower than most test systems can even measure. But most important to MUSIC rather than TEST SIGNALS, and very different from Delta Sigma DACs the MSB DAC module are most accurate with signals crossing zero, where music actually exists.
Sample Rates
When we talk about digital sample rate we mean the speed of the bits in kHz. CDs are 44.1 kHz (44.1 thousand times per second), and higher resolutions typically go up to 192 kHz with the next generation of hi-res recordings just now available at 384 kHz. MSB DAC modules can operate beyond 5 mHz (5 million times per second), so these modules can receive and reproduce all current formats and conceivable future formats for many years to come. Unlike Delta Sigma DACs the performance of the MSB ladder DAC actually gets better with more bit depth and recording resolution. Low level resolution is recovered to an extraordinary degree"
Cheers George