Low-Jitter Oscillator

This product is discontinued. This is an archived page.

The problem of Jitter in digital audio conversion can be understood when you think about Fourier synthesis of a square wave. A square wave is made up of an infinite number of harmonics. So, to generate and to transport something even close to a square wave running at 33.8688 MHz, you need to have completely controlled electromagnetic circumstances well up into the multi-Gigahertz region (for true-to-life quality even up to infinity). It may be argued that timing Jitter is born of the very noise inherent in any electromagnetic space, and this includes a complete vacuum just as it includes a brick and mortar wall.

Realizing this, the makers of the LessLoss DAC 2004 minimize Jitter by means of synchronously re-clocking the digital signal at crucial stages along the path that this highly sensitive signal must travel. This is necessary because no digital signal is immune to the multiple sources of Jitter, which includes the passage of the signal through the noise inherent in the nature of electromagnetic space. The less Jitter, the better the audio. So we want no Jitter. In order to avoid a jittered signal, a low-jitter Master oscillator is required, which is built into the DAC 2004 and located as close to the actual converting components as possible.

Lowest Jitter Clock Oscillator

The digital input section of the LessLoss DAC 2004 contains an extremely low jitter high frequency oscillator running at 33.8688 MHz. The heart of this low jitter clock is the high quality quartz oscillator. The pure and predictable voltage given to drive this component is key to its practically jitterless functioning.

We use a very high quality analogue quartz sinus generator which is later turned into a square wave digital signal by means of a super fast comparator chip. In this way we achieve the best possible results.

Jitter

This is Jitter as it might be depicted in a low budget Hollywood film. Highly oversimplified and very black-on-white, this serves to show visually that Jitter is a distortion of the time domain. The best method of overcoming Jitter is to minimize the distance between the oscillator and the converter chip. Any piece of semi-professional digital audio equipment is capable of running in both MASTER and SLAVE modes.

  • Digital MASTER means that the device is running off of its own internal clock. The distance between the converter chip and the oscillator is small (internal wiring only).
  • Digital SLAVE means that the device is running off of yet another device's internal clock. This means that there is an external cable bringing the clock signal from the external piece of equipment (the Master) to the Slave. However, this clock signal needs to be extracted from the complex digital signal containing not only the clock but also the changing audio information itself, whose irregularity also introduces jitter.

Perhaps the worst problem with using an external DAC in conjunction with a common household CD player is that the CD player is always the Digital MASTER. Although the LessLoss DAC 2004 outperforms most any DAC even in SLAVE mode, the truly highest performance is obtained while using the DAC 2004 in MASTER mode.

Less Loss Leads to Hi-Fidelity

There is a clock output from the DAC 2004 which enables the user to slave an external digital source such as a CD player or digital sound card to the DAC (provided the soundcard has a superclock 256F input). In this way, the source digital player, or signal provider, is locked to the ultra-low-jitter clock from the DAC. The converter chip (the PCM 1704) is also locked to the very same clock. Because both source and converter are both locked to the same clock, Jitter is maintained at extremely low levels.

In order for a household CD player to function in this way, it must be modified. Only a few commercially available models exist which can run in slave mode. These players are among the most expensive in existence. We provide you with information as to how to do this to an average unit but we will not accept any responsibility for the destiny of your equipment. It's easy [if you can solder]. There will be no further support offered from our part but we believe that there are plenty of experienced enthusiasts worldwide who would take the time to make this simple yet most effective modification.


Less Loss Leaves No Leaf Unturned

Because LessLoss is determined to minimize jitter to the lowest of possible levels, we go the extra step to re-clock (also known as quantizing) the digital data to near-perfect timing just a few millimeters before it enters the audio domain. (This image helps depict graphically what this process does -- green is where the signals should be on the graph paper, and red is where the signals are due to Jitter. The re-clocking slides them back into place.)

Jitter