Black Friday Special - Buy 2 Components and Save 10% (Orders Over $3798 Only) - Free shipping on all orders over $700.

    0

    Your Cart is Empty

    Products
  • AHB2 Power Amplifier Black

    Power Amplifier

  • HPA4 Headphone Amplifier Silver

    Headphone Amplifier

  • LA4 Line Amplifier Silver

    Line Amplifier

  • Digital to Analog Converters

  • UltraLockDDS™ Clock System

    by John Siau November 01, 2010 2 min read

    UltraLockDDS™ Clock System

    New Clock Technology from Benchmark

    When Benchmark unveiled UltraLock™, it caused quite a stir. Benchmark claimed that this proprietary clock-syncing system made their converters immune to jitter. UltraLock™ keeps jitter-induced distortion at or below -135 dB FS (well below audibility). Of course, the audio community was skeptical; they set out to prove (or disprove) Benchmark’s claims. Since then, several journalists, end-users, and manufacturers of audio test-equipment have verified Benchmark’s claim of jitter-immunity.

    However, there was still room for improvement. There is an asynchronous sample rate conversion (ASRC) process in UltraLock™ that adds about 1 millisecond of latency. This latency is usually only of concern when musicians are monitoring themselves real-time, post-converter. Even in this case, 1 millisecond of latency is hardly noticeable; it is roughly equivalent to having the instrument 1 foot further away. Nevertheless, it can contribute to a system-wide latency problem.

    When designing the ADC16, Benchmark decided to revisit its clock-management solution, to reduce latency. The technology that Benchmark developed during this quest is called UltraLockDDS™.

    Benchmark’s new UltraLockDDS™ clock system utilizes the latest low-jitter clock technology developed for high-frequency RF communications systems. The master oscillator is a low phase-noise, temperature-compensated, fixed-frequency crystal oscillator with a +/- 2 PPM frequency accuracy. This oscillator drives a 500 MHz Direct Digital Synthesis (DDS) system that generates a 3072 x WC system clock. This high-frequency clock is divided and distributed directly to the A/D converters using a high-speed PECL clock distribution chip. Each of the 8 converters is driven directly through a dedicated, matched-impedance transmission line.

    Jitter attenuation is achieved with digital filters in a custom FPGA that controls the DDS system. All jitter-induced distortion artifacts are well below audibility under all operating conditions. Jitter-induced distortion is always at least 135 dB below the level of the music. The jitter-performance of UltraLockDDS™ meets or exceeds the performance of Benchmark’s UltraLock™ system, but does not use an ASRC DSP process. The elimination of the ASRC processing significantly reduces system lateancy and provides the most direct path from the A/D to the digital interface.


    Also in Audio Application Notes

    Closeup of Plasma Tweeter

    Making Sound with Plasma - Hill Plasmatronics Tweeter

    by John Siau June 06, 2023 2 min read

    At the 2023 AXPONA show in Chicago, I had the opportunity to see and hear the Hill Plasmatronics tweeter. I also had the great pleasure of meeting Dr. Alan Hill, the physicist who invented this unique device.

    The plasma driver has no moving parts and no diaphragm. Sound is emitted directly from the thermal expansion and contraction of an electrically sustained plasma. The plasma is generated within a stream of helium gas. In the demonstration, there was a large helium tank on the floor with a sufficient supply for several hours of listening.

    Hill Plasmatronics Tweeter Demonstration - AXPONA 2023

    While a tank of helium, tubing, high voltage power supplies, and the smell of smoke may not be appropriate for every living room, this was absolutely the best thing I experienced at the show!

    - John Siau

    Read Full Post
    Benchmark AHB2 Power Amplifier

    Audio Calculators

    by John Siau June 04, 2023 1 min read

    We have added an "Audio Calculators" section to our webpage. Click "Calculators" on the top menu to see more like these:

    THD % to dB Converter
    RESULTS
    THD dB to % Converter
    RESULTS
    Read Full Post
    Benchmark AHB2 Power Amplifier

    System Performance Calculations

    by John Siau June 03, 2023 13 min read

    If an audio system is composed of multiple components, we may have detailed specifications for each component, but we will not know the performance of the combined system without doing some calculations. You may have questions such as these:

    • Will my audio system produce audible noise?
    • Will my audio system produce audible distortion?
    • How will my audio components work together as a system?
    • How loud will my audio system play?

    Use Benchmark's online audio calculators to find answers!

    For example, if we know the output power of an amplifier, as well as the sensitivity and impedance of our loudspeakers, we can calculate the maximum sound pressure level that our system can produce.

    PEAK SPL CALCULATOR
    dB SPL (2.83 V,1 M)
     Watts
    RESULTS
    dB SPL

    This application note provides interactive examples that help to answer the questions listed above.

    Read Full Post