Pro-Ject DAC Box RS2 Digital-to-Analog Converter - Silver

Tubes or Transistors, Chosen From Your Chair

The DAC Box RS2 has a switch most converters do not. It moves the output stage between a solid-state path and a tube path running four 6922EH valves. Same box, same recording, two voicings, and no need to decide once and live with it.

The measurements show it is a real choice rather than a novelty. Pro-Ject publishes THD+N under 0.0008% through the solid-state path, and 0.001% through the tubes, both measured at 2V RMS and 1kHz. That second figure is the tube character, left in on purpose.

Conversion runs on two ESS9038Q2M chips in dual mono, handling PCM to 32-bit/768kHz and DSD512, with full MQA unfolding done in hardware. The chassis is 206 by 72 by 222mm and weighs 1,520 grams, in silver or black.

Six Ways In, Balanced and Unbalanced Out

The input list is unusually deep for a small chassis. USB 2.0 takes 32-bit/768kHz plus DoP and native DSD to DSD512. An HDMI I2S input is there for Pro-Ject's CD Box RS2 T transport, keeping clock and data separate rather than combined.

Alongside those sit two optical inputs, one coaxial and a balanced AES/EBU input, each accepting 24-bit/192kHz. AES/EBU is rare at this size and is what broadcast and studio gear expects to see on the other end of a cable.

Outputs are balanced XLR and unbalanced RCA. This is the Pre Box RS2 Digital with the analog preamplifier section taken out, so the output runs at a fixed level and the conversion is what you are paying for.

Who Is This DAC Best For?

• You cannot decide between tubes and solid state — the output stage switches between them, so you choose per record rather than per purchase, and the tube path is measured rather than merely claimed.
• Your system is balanced — XLR outputs and a balanced AES/EBU input mean the signal can stay balanced from a studio-grade source right through to your amplifier.
• You still play discs — the HDMI I2S input is built for Pro-Ject's CD Box RS2 T, so a matching transport connects on a link designed for it instead of an adapted one.
• Your library includes everything — PCM to 768kHz, DSD512 and full hardware MQA unfolding mean no file in your collection arrives in a format it cannot open.
• You want a volume control on it — this is the DAC-only version, with a fixed output and no preamplifier section, so it needs something with a volume knob after it. If you would rather have that built in, the Pre Box RS2 Digital is the same converter with the preamp and headphone stage added.

How Does It Connect to Your System?

Run the XLR outputs to a balanced input on your preamplifier or integrated amplifier, or the RCA pair if it is single-ended. Because the output is fixed, the volume control lives in whatever follows.

A computer joins over USB, a Pro-Ject transport over HDMI I2S, and disc players or a television over coaxial or optical. Studio and broadcast sources take the AES/EBU input. Then pick tube or solid state and listen.

Pairs Well With

Building around the DAC Box RS2? Here are some great companions:

• Preamplifier: The output is fixed, so volume lives here — see our Preamplifiers.
• CD Transport: The I2S input is waiting for one — see our CD Players & Transports.
• Music Streamer: Feed the USB or coaxial input — see our Music Streamers.
• Interconnects: Balanced XLR keeps the path balanced — see our Interconnect Cables.

Frequently Asked Questions

What does the tube and solid-state switch do?

It selects between two complete output stages: a solid-state path measuring under 0.0008% THD+N, and a tube path using four 6922EH valves and measuring 0.001%.

What converter is inside?

Two ESS9038Q2M chips in dual mono, handling PCM to 32-bit/768kHz and DSD512, with full hardware MQA unfolding.

Which inputs does it have?

Six: USB 2.0, HDMI I2S, two optical, one coaxial and one balanced AES/EBU. The optical, coaxial and AES/EBU inputs each accept 24-bit/192kHz.

What is the I2S input for?

It is a direct digital link designed for Pro-Ject's CD Box RS2 T transport, carrying clock and data on separate lines rather than combined into one stream.

How does it differ from the Pre Box RS2 Digital?

The same conversion, without the analog preamplifier section. The DAC Box RS2 runs at a fixed output level; the Pre Box adds volume control and a headphone stage.

What size is it, and what finishes are there?

206 by 72 by 222mm and 1,520 grams without its supply, in silver or black. It runs from a 20V DC supply.

See It in Action

Our own look at the DAC Box RS2 and what the switchable output stage does:

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Learn More

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