The world-class audio performance of Warwick’s HPEL Drive Electronics PCB-A is exemplified by the attention to detail and refusal to compromise evident in all aspects of the circuitry design. A brief description of a few of the design elements illustrates Warwick’s commitment to audio performance.
Class A Energizing Amplifier
Like all electrostatics, the HPEL transducer requires a high voltage drive amplifier in order to function. The supplied drive comes from an optimally-matched, high performance, discrete FET Class A amplifier with very low distortion and wide bandwidth.
Custom 64-Bit Double-Precision Fixed-Point DSP
We digitally process all signals using custom 64-bit, double-precision, fixed-point arithmetic. Fixed-point is known to be superior in the world of audio processing. And our 64-bit arithmetic exceeds even the performance of professional audio workstations.
AKM Premium ADC
All incoming analog signals must be converted to digital ahead of the DSP. To achieve this, we utilise a multi-channel 32-bit/384 kHz AKM Premium ADC, which delivers a measured signal-to-noise ratio in excess of 120 dB.
CRYSTEK Ultra-Low Phase Noise Oscillator
The ultimate performance of any digital system is determined by the quality of its master clock. To guarantee the highest performance regardless of the input signal format, we utilise an ultra-low phase noise oscillator from Crystek. Operating at 100 MHz, it features extremely low close-in phase noise (< 90 dBc/Hz at 10 Hz from the center frequency) and an industry-leading rms jitter level, at 100 MHz, of 82 femtoseconds (82 x 10-15 s). All other clocks used are derived from this exceptionally accurate master oscillator via a sophisticated clock distribution scheme using Texas Instruments frequency dividers.
ESS SABRE Reference DAC
ESS is universally recognized as the world’s premium DAC chip manufacturer, and we have opted for their 32-bit Reference DAC. Each DAC chip is operated in mono mode to provide a measured 129 dB signal-to-noise ratio.
Optimum PCB Layout
The use of premium parts alone does not guarantee high quality audio performance. In the design of the PCB-A, meticulous attention was paid to circuit layout to ensure the lowest noise and distortion levels possible. Through careful component positioning, we were able to lower the noise floor to below -129 dB.
Two-Stage Power Supply
All audio circuitry is supplied by multiple stages of ultra-low noise, high current linear regulators from Analog Devices. Isolated power regulation stages are used for both analog and digital sections as well as high and low level circuit stages. These regulation stages are fed by a custom-designed, universal voltage, outboard switch-mode power supply unit, capable of delivering about 3.5 times the maximum power the amplifier is designed to draw under steady-state conditions. In addition, the unit uses a fixed high frequency switcher (operating at over 85 kHz) to avoid the possibility of any switching noise entering the audio band. This unit is designed with improved internal filtering to yield extremely low noise and ripple (< 50 mV peak-to-peak).