I have been involved with many successful designs of audio accessories, but two stand out: the HCPS and Digital Lens. The first came about by accident, the second by design. Today we focus on the second.
I have likely written on the subject of the Lens before but it seems worthy to do it again in different words. The Digital Lens is a regenerator for digital audio. LIke the venerable Power Plant AC regenerator, a Lens recognizes incoming data, throws away the original, rebuilds new and jitter free digital audio before the DAC gets it.
First produced in the mid 1990’s, the product was a wild hair idea of mine designed, developed, prototyped and crafted by our Chief Engineer, Bob Stadtherr. Final tweaking and voicing was performed by my partner in Genesis Technologies, Arnie Nudell. We had noticed the output of DACs varied greatly with different cables and transports. Neither Arnie nor I bought into the ‘bits is bits’ foolishness, but frankly we were surprised at the extent they mattered. We both suspected timing and wave shape as culprits.
Most engineers rely on postulates to visualize the mechanisms of problems. If timing (jitter) were to blame for variations in sound quality, I had imagined we could prove that by removing the suspected clock/data relationship. We know jitter does not occur in stored data without reference to a clock. It is only when that data and clock are paired we risk jitter. Therefore, multiple copies of identical data, even those delivered over disparate mechanisms, should sound identical when output from a storage device controlled by a common clock. Thus, the audio RAM buffer was ‘invented’ to solve sonic differences.
RAM buffers were not new, though their use in an accessory to improve DAC performance was. We soon learned there was much more going on that also needed fixing and we’ll cover that list tomorrow.