D/A Converter Ypsilon Electronics DAC 1000 Silver

No-oversampling D/A converter with a discrete R2R ladder and a tube analogue stage

The DAC 1000 is a no-oversampling digital-to-analogue converter that processes the digital signal without upsampling and without digital filters ahead of the conversion stage. Six inputs are available — Coax, BNC, AES and optical with support for PCM 24/192, plus USB and I2S over an HDMI connector supporting PCM 24/384. Over USB you can also play DSD files from a computer or server up to DSD256, natively, with no conversion to PCM.

PCM conversion is handled by an in-house discrete R2R ladder built around fast logic and precision resistors. The DAC 1000 version uses Vishay metal film resistors with tight tolerances and low drift, while the SE version works with custom-made naked foil types. Native DSD conversion is taken care of by a combination of a separate transformer and chokes with an AKM chip, of which only the output stage is used; the converter detects the presence of a DSD signal automatically and routes it to the appropriate path.

The USB input is galvanically isolated and powered by internal supplies, with reclocking handled by local oscillators with extremely low phase noise. The I2S input offers the shortest signal path with no further processing — LVDS transmission over an HDMI connector carries the digital audio signal without added jitter, is isolated against ground loops, and the signal is re-aligned to the incoming master clock. The result is a stable time base and a low noise floor at the output, which shows itself in the legibility of microdetail and precise localisation of instruments.

The analogue section is built as a single-ended triode stage with Siemens tubes (one per channel). Coupling between the converters and the tube uses a proprietary “wire capacitor”, keeping the signal path as simple as possible. The tube is transformer-coupled to the output, resulting in a very low output impedance of 30 ohms and trouble-free matching with a wide range of amplifiers. The power supply works with a rectifier tube and a choke in the high-voltage rail, which reduces the noise fed to the tubes. All functions are shown on an LCD display and can also be controlled by remote.

Key features

• Converter: Discrete R2R ladder 24 bit / 384 kHz with no oversampling
• Inputs: SPDIF, BNC, AES, optical, USB and I2S
• DSD: Native DSD256 playback over USB
• Analogue stage: Siemens triode tubes with transformer output
• Output: 2.8 V rms, output impedance 30 ohms