To the audiophile, Prism Sound might not be the first name that trips off the tongue when it comes to high-quality digital audio coming out of the Cambridgeshire countryside. But, if you are in the studio, broadcast, or even audio test equipment world, this specialist from the tiny village of Stretham is a name to be reckoned with. This year, Prism Sound crossed the audio Rubicon and has made its first domestic product, the Callia DAC with built in headphone amplifier and preamp.
Essentially the Prism Sound Callia uses the form factor, some of the ergonomics and much of the digital nous of Prism’s Lyra USB interface; in the process gaining domestic inputs and outputs, but losing an A/D converter. Callia also supports RCA and Toslink S/PDIF, and the RCA input can be used in a professional capacity as it supports AES3-ID. In terms of formats, the Audio Class 2.0 USB input supports DSD over DoP to DSD128, and PCM to 32‑bit word lengths and 384kHz sampling rates. However, sampling frequencies beyond 192kHz are passed through a high-performance decimation filter, so hunting down 32/384 files isn’t important in this case. S/PDIF supports PCM up to 24‑bit word lengths, with multiples of 44.1kHz and 48kHz sampling rates up to 192kHz, and DSD64 within a DoP frame.