The CAD 1543 MKII DAC has used as few components as possible in the signal path. For that reason we do not offer additional inputs or outputs. The digital signals travel less than 1 cm from the USB board to the DAC chips. Due to there being only one input the digital signals do not pass through any switches. Digital signals run at extremely high frequency (MHz) and sound quality can be significantly reduced when switches are used in the digital domain. DAC chips are isolated from the USB input – Computers do not have very good power supplies for audio equipment. But many DACs on the market make use of this power to drive the DAC. The 1543 MKII DAC has proprietary galvanic isolation from the connected computer. Galvanic Isolation means that no current from the computer flows into the DAC chips. The +5V connection inisde the USB cable is not used and is not necessary with the CAD 1543 MKII DAC. Asynchronous USB input – With a normal USB (either synchronous or adaptive) input the data is sent by the computer using the computer’s clock. The DAC must extract the data when the computer sends it. A serious issue with this process relates to a type of digital distortion called jitter. Computers have high amounts of jitter and we believe jitter is a major cause of poor sound quality. With Asynchronous USB input the DAC receives the data from the computer and then using its own clocks the data is sent on to the next stage in the DAC. We use custom fixed frequency oscillators in our DAC. We supply these oscillators with power supplies that we have developed to achieve the best sound quality possible. Power Supplies – One of the first questions we usually get about our DAC is “what chip do you use?” We agree that the DAC chip is very important, but most people do not realise is that the power supplies are at least as important! We have spent a huge part of our research on developing the power supplies for the 1534 MKII DAC. Our power supplies are our own design and unlike anything else on the market. Non Over Sampling DAC – We are trying to reproduce a more natural “analog” sound that is typical of well- designed turntables. We are convinced that Non-Over-Sampling DACs achieve a more realistic natural musical experience. R-2R resistor ladder DAC chip technology – CAD believes that sigma delta technology used in current DAC chips does not sound as natural as resistor ladder technology. The CAD 1543 MKII DAC is so-called because it uses sixteen vintage Philips TDA1543 chips, which undoubtedly contribute to its signature sound quality.