Streamers — Pro-Ject BT Box E HD

The BT Box E HD is a Bluetooth receiver from Pro-Ject Audio Systems that adds wireless playback from phones, tablets and computers to an existing hi-fi system. It belongs to the E range of the Box Design series, manufactured by Canor of Presov in Slovakia and distributed by Pro-Ject in Vienna. The model appeared in October 2022 at GBP 119 in the UK. The case is offered in black or white, and an outboard power supply for 220 to 240 V mains at 50 or 60 Hz comes in the box.

Key specs that matter

The radio section uses Bluetooth 5.0 with the A2DP profile and accepts SBC, aptX and aptX HD, working between 2402 and 2480 MHz with a sensitivity of -88 dBm. Range is up to 10 m with direct line of sight. The analogue line output delivers 2.0 Vrms at 0 dBFS, with frequency response of 20 Hz to 20 kHz within 1.5 dB, signal-to-noise ratio above 93 dB and THD under 0.03 percent at 1 kHz. The optical output reaches more than 120 dB signal-to-noise and THD under 0.01 percent, and channel separation is better than 113 dB on the line output and 140 dB on the optical output, at 10 kHz. The supply is rated 18 V at 500 mA, while the unit draws no more than 50 mA and under 1 W on standby. It measures 120 x 32 x 100 mm, or 115 mm deep with sockets, and weighs 250 g without the supply.

Engineering and use context

Pro-Ject states that aptX HD keeps playback stable even when the Bluetooth link quality drops for a moment. Pairing takes three to five seconds, and the unit remembers up to eight devices, though it plays from only one at a time. To change source the current phone must disconnect before the next one pairs. On an Android device the owner opens the Bluetooth settings, scans and taps the BT Box E HD entry, confirming a code if asked, and Apple devices list it once Bluetooth is switched on. If a device drops out of range for a few seconds it reconnects on its own when it returns. Both outputs are live at the same time, so the RCA pair can feed an amplifier line input such as AUX while the Toslink output goes to a DAC, an AV receiver or a digital amplifier input. Using the optical output hands conversion to the downstream DAC.

Pairing

Any integrated amplifier, receiver or powered speaker with a spare line input takes the RCA output, and a system built around an outboard DAC can use the optical link.

Alternatives

The Pro-Ject BT Box S2 HD is a Bluetooth 5.0 aptX HD receiver in the S2 range with a dedicated analogue output buffer stage.