How can a DAC with no oversampling and limited hi-res capability sound so good?
The answer may be found in two areas.
Early CD players sounded unnatural and uninvolving and the same can be said about most of the current generation of hi-res players. It may be that hi-res will eventually reach the musicality of a well executed Redbook design but they are not there yet.
The second area is the power supply. Being a BorderPatrol design, the power supply received a lot of attention and early experiments proved just how important it is. Improvements to the power supply dramatically improved the sound of the DAC proving that its not what you use but how you use it that counts. After much testing and evaluation, a hybrid tube/solid state design using choke input filtering was found to be the most musical, dynamic and organic. BorderPatrol is the only company that applies tube rectification and choke input filtering to digital circuits.
Also unusual for a product of this price, the DAC is housed in copper casework chosen for it's rich, lustrous sound quality
Natural, sweet, open and organic are not words usually used to describe digital electronics but those were the design goals for the BorderPatrol DAC. Too many digital audio products sound processed, unnatural and uninvolving and this is particularly true of many of the new generation of hi-resolution DAC's. The most natural sounding DAC’s are usually NOS (no over-sampling) designs based around the R-2R resistor ladder chips with no digital filtering. When carefully implemented, designs like this can sound refreshingly natural and organic.