DACs — CH Precision C1.2

The C1.2 is a DAC and system controller from CH Precision, the Swiss high-end electronics maker. Launched at High End Munich in 2022 as the successor to the C1 and the partner for the D1.5 CD/SACD transport, it keeps its predecessor's modular, configurable format but re-engineers the entire digital signal path. It was priced at about EUR 32,850 with one digital input card, and a dual-monaural C1.2 Mono configuration was also offered.

Key specs that matter

Conversion uses four Burr-Brown PCM1704 R-2R (ladder) converters per channel in a fully complementary, dual-mono symmetrical circuit. All PCM is oversampled to 24-bit at 705.6kHz or 768kHz, and DSD, accepted via DoP up to DSD512, is converted directly to 705.6kHz PCM. Processing runs on independent 2.4 GFLOPS DSP engines using CH's PEtER algorithm. Signal-to-noise ratio is 120dB and THD+N 0.001%. Inputs are chosen by the owner from optional cards, such as an HD digital input, an Ethernet streaming card or a USB card, and analogue inputs can be added. The chassis measures 440 x 440 x 133mm and weighs 20kg.

Engineering and use context

PEtER is CH Precision's own upsampling filter, which uses spline interpolation to calculate new sample points between the original PCM data. For the C1.2, processing power was increased four-fold, allowing the algorithm to be refined and moved to 32-bit fixed-point processing, and it also improves the resolution of material recorded below 24 bits. The PCM1704 is a long-discontinued ladder DAC chip valued for its linearity. A new MEMS-based master clock, thermally compensated and shunt regulated, improves clock accuracy and reduces timing error, while discrete local regulation for the DSP and FPGA chips and new power-management software lower the digital noise floor. Each channel has dedicated, fully regulated linear power supplies. Volume control is a hybrid digital/analogue design that can be bypassed when the C1.2 feeds a preamplifier. MQA is fully supported for both disc and file playback. The modular chassis lets owners buy only the inputs they need and later add an external power supply, a T1 Time Reference master clock, or convert to a three-box dual-mono DAC. The unit is controlled by the CH app on Android devices.

Pairing

With its volume control and analogue inputs, the C1.2 can act as the system controller, driving power amplifiers such as CH Precision's A1.5 or M1.1 directly, or feed a separate preamplifier with volume bypassed. The D1.5 transport is its intended disc source.

Alternatives

CH Precision's own C10 uses eight PCM1704 converters per channel and a two-stage PEtER process in a higher-level DAC.