Prism Sound AD-2 AD Converter

Prism Sound AD-2 AD Converter

Performance
Converter performance is pushed ever-nearer the limit: Dynamic range reaches a massive 130dB, THD+N at full scale is raised to 108dB (0.0005%). Clock stability, and rejection of incoming reference jitter are also improved.

Flexibility
The AD-2 is like two separate A/D converters, plus a digital processor, all in one: it can generate two entirely separate output signals simultaneously. These can have different sampling rates, different word-lengths – even use different noise-shapers. For example, you can output a 96kHz / 24-bit signal and a 44.1kHz / 16-bit noise-shaped signal at the same time.

Apart from its breathtaking performance, the analogue front-end of the AD-2 includes many new features: Analogue input sensitivity (and inter-channel balance) is software-programmable over the entire range with 0.05dB resolution. Just as with the AD-1, the inputs are transformerless, electronically balanced and galvanically isolated (fully floating), to ensure freedom from noise pick-up and crosstalk.

Digital to Digital Sample Rate Conversion
The ‘D-D’ (digital-to-digital) path, first provided in the AD-1, has been improved still further in the AD-2: It still offers re-dithering, noise-shaping and DRE encoding / decoding, but now it has synchronous sample-rate-conversion (SRC) as well. So you can re-process your 96kHz, 24-bit masters to 44.1kHz 16-bit streams for CD, or you can up-sample low-rate recordings for post-processing at a higher rate… in fact, you can convert between any two standard sampling-rates – synchronously. Synchronous sample-rate-conversion, if correctly performed, is free of the distortion artifacts associated with conventional ‘variable-rate’ SRCs.

Noise Shaping
The four tried and tested Super-Noise-Shaping (‘SNS’) curves are extended to include optimal shaping for the higher sampling rates. The SNS process gives greatly-improved small-signal performance for limited word-lengths, such as CD, and is completely compatible with existing D/A converter products (including consumer and professional CD players).

Dynamic Range Enhancement
The popular DRE function is retained from the AD-1: this allows you to make 24-bit quality recordings on 16-bit recorders such a DAT. DRE (Dynamic Range Enhanced) recordings need to be decoded on playback; the decode function is provided as an option in the ‘D-D’ mode. DRE, unlike conventional dynamic-range processing does not compress or add HF noise.

Precision Metering and Control
The AD-2’s front panel gives a clear indication of the main control settings at all times. Audio level is shown on 16-segment meters complemented by a precision digital level readout in the LCD display. A menu system allows control of operating parameters, and 16 stores are provided (including eight ‘factory’ modes) which can be recalled at the push of a button. A unique ‘Setup Wizard’ feature simplifies configuration of the AD-2 for new users.

Versatile I/O
The digital inputs and outputs of the AD-2 cover a wide range of formats. Digital outputs are available in all formats irrespective of the input format in use. When generating two different output signal paths, the AD-2’s digital outputs can be freely assigned to either path.

The Last Word
We’ve been very busy since our first generation converters came out in 1994. Take a long look at the AD-2 and DA-2 and you’ll see why. We have compromised on nothing: these converters quite simply redefine the state-of-the-art.