Meeting Topic: How To Avoid Digital Jitter
Moderator Name: Robert Breen
Speaker Name: Morten Lave, CEO/Managing Director, TC Applied Technologies
Other business or activities at the meeting: Call for nominations for upcoming Toronto Executive Elections
Meeting Location: Eaton Theatre, Ryerson University, Toronto ON Canada
How to Avoid Digital Jitter
This meeting was a practical exploration of digital jitter, what are the symptoms and how do you avoid them? Is the digital source responsible for the problem or is it the sync device?
Morten Lave, CEO and Managing Director of TC Applied Technologies, spoke about the history of jitter and the work of some of the leading researchers in this area, such as Julian Dunn, and their results.
There are two distinct results of jitter; jitter which prevents your AES receiver from locking, and jitter which affects your sound quality and stereo image etc. Morten cleared up several commom misconceptions about jitter... most interestingly that a good master clock will prevent jitter from ocurring. This is only partially true. A good clock is only as good as the slave's ability to lock to it, a result of the quality of its PLL or Phase Lock Loop circuit.
Many digital systems are much more jitter free when locking to their internal crystal, which is inherently very accurate. The problem arises when multiple systems are linked, and a good PLL has traditionally been very expensive to implement. Morten briefly discussed TC's JET PLL technology, which addresses this issue, mixing inexpensive digital and analog components to create a clean clock for the slave to lock quickly and accurately.
For further information, and for tests to determine the jitter in your system, please see the following links:
http://www.nanophon.com/ (dedicated to the work of Julian Dunn)
http://www.tnt-audio.com/clinica/jitter2_e.html(a great summary of jitter and its effects)
http://www.digido.com/audiofaq.html (see "jitter")
Recommended reading:
Bob Katz, Mastering Audio, The Art and Science
Morten Lave, CEO/Managing Director, TC Applied Technologies (BIO)
Morten Lave, CEO/Managing Director of TC Applied Technologies is an expert in digital and analog design, IC design, firmware and software design and digital signal processing. As a teenager, he developed a digitally controlled analog guitar effects processor around a Zilog Z80 with a friend. The unit featured parametric EQs, chorus/flanger, compressor and mixer. It even had a connector for VCA control of the guitar amp — the system provided the user with 64 presets and a custom foot controller. It was a DIY project that set the pace for a successful career spanning decades.
He received his master's degree in computer science from Aarhus University in Denmark in 1990 after completing a bachelor's degree in physics. From 1989, he was employed at TC Electronic in a small R&D department; he implemented all software, firmware and DSP code for all TC Electronic products released in the first half of 1990s — including TC6032, M5000, M2000 and Finalizer.
As TC Group expanded, so did its development department; in 1995 he became the R&D manager for the software and chip department that would grow to 40 strong before he left the company in 2003 to set up TC Applied Technologies. From 1999 to 2003, Morten also served on the Board of Directors for TC Group. Despite his managerial duties, he continued to be heavily involved in code writing and architecture design; both have always been his passion.
Since 2003, Morten has served as CEO and managing director of TC Applied Technologies, a fab-less semiconductor company focusing primarily on the development and delivery of IEEE1394 (FireWire) semiconductors and supporting A/V networking technologies for the professional and consumer electronics sectors.
