Prism Sound Dream AD-2 was released in 1998 as Prism Sound’s next-generation reference analogue to digital converter, building directly on the design principles of the earlier Prism Sound AD-1 and Prism Sound AD-124. It was conceived for the most demanding professional applications in sound recording, mastering and broadcast, combining extreme converter performance with an unusually powerful and flexible internal digital processing architecture. With the Dream AD-2, Prism Sound set out to redefine the practical limits of standalone A/D conversion rather than merely incrementally improve on previous designs.
At the heart of the Prism Sound Dream AD-2 is an analogue to digital conversion system pushed very close to theoretical limits. Dynamic range reaches a massive 130 dB, while THD + N performance at full scale is specified at -106 dB. Clock stability and rejection of incoming reference jitter were further refined compared to earlier Prism Sound designs, ensuring exceptionally stable imaging and freedom from time-domain artefacts even in complex synchronised digital systems. These characteristics made the Dream AD-2 particularly attractive for mastering and critical recording where absolute transparency was essential.
The architecture of the Prism Sound Dream AD-2 is effectively that of two independent A/D converters plus a digital signal processor within a single chassis. The unit can generate two completely separate output signal paths simultaneously, each with its own sampling rate, word length and noise-shaping characteristics. This allows, for example, a 96 kHz 24-bit master output to be generated at the same time as a 44.1 kHz 16-bit noise-shaped signal for CD production, without requiring additional conversion stages or external processing.
The analogue front end of the Prism Sound Dream AD-2 introduced several refinements over earlier models. Analogue input sensitivity and inter-channel balance are software adjustable across the entire range with extremely fine 0.05 dB resolution, allowing precise alignment in mastering and multi-channel environments. The Prism Sound Over-killer soft-clipping system is built in, offering a selection of soft-clipping characteristics to gently control transient overloads while preserving musical integrity. As with earlier Prism Sound converters, the inputs are transformerless, electronically balanced and fully floating, ensuring minimal noise pickup and crosstalk.
Digital to digital processing was also significantly enhanced in the Prism Sound Dream AD-2. The D-D signal path supports re-dithering, noise-shaping and DRE encoding and decoding, but adds fully synchronous sample-rate conversion. This allows conversion between any of the supported standard sampling rates without introducing the distortion artefacts associated with conventional asynchronous sample-rate converters. High-rate masters can therefore be cleanly converted to CD-ready formats, or lower-rate material can be up-sampled for processing, all within the same unit and under synchronous control.
The four established Prism Sound Super Noise Shaping curves are extended in the Dream AD-2 to optimise performance at higher sampling rates. These processes provide greatly improved low-level resolution when reducing word length and remain fully compatible with all existing consumer and professional digital to analogue converters. The DRE Dynamic Range Enhancement system is also retained, allowing 24-bit quality recordings to be stored on 16-bit media such as DAT, with decoding available in the digital to digital mode. Unlike conventional dynamic range processing, DRE does not compress the signal or add high frequency noise.
Operationally, the Prism Sound Dream AD-2 is designed to balance power with clarity. The front panel provides constant visual feedback of key operating parameters, with 16-segment meters displaying audio levels. A menu-based control system is supported by 16 internal memories, including eight factory presets, allowing complete configurations to be recalled instantly. A dedicated Setup Wizard guides new users through configuration, reducing setup errors in complex production environments.
Digital connectivity on the Prism Sound Dream AD-2 spans a wide range of professional and consumer formats. AES3, S/PDIF and SDIF-2 connections are provided as standard, with full format conversion available between all supported connector types. When operating with dual output signal paths, any digital output can be freely assigned to either path, reinforcing the unit’s role as both a reference converter and a flexible digital processing hub.
The Prism Sound Dream AD-2 represents a defining moment in the evolution of high-end digital conversion. By combining extreme analogue performance, advanced digital processing and an unusually flexible architecture, it established a benchmark for standalone A/D converters that influenced professional converter design for many years.
Features
- Reference-grade analogue to digital conversion for recording, mastering and broadcast
- Dynamic range of up to 130 dB with extremely low distortion
- Dual simultaneous output signal paths with independent formats and processing
- Software-adjustable analogue input sensitivity and channel balance
- Integrated Prism Sound Over-killer soft-clipping system
- Synchronous sample-rate conversion in digital to digital mode
- Four Super Noise Shaping curves optimised for multiple sampling rates
- DRE Dynamic Range Enhancement encoding and decoding
- Comprehensive digital format conversion between AES3, S/PDIF and SDIF-2
- User memories and Setup Wizard for fast and reliable configuration