ЦАПы — TOPPING DX3 Pro+

The DX3 Pro+ from TOPPING pairs digital conversion with a headphone output stage on the desktop, adds Bluetooth reception, runs from an external 15 V supply and comes with a remote control. It can work as a headphone amplifier, a headphone amplifier with active line out, a pure DAC or a preamplifier, so one unit can be a desktop headphone rig or the source hub of a compact stereo system. The box also holds a Bluetooth antenna and a USB cable.

Key specs that matter

TOPPING fits an ESS ES9038Q2M chip, taking USB data from an XMOS XU208 USB processor, a second generation 8-core part that accepts PCM up to 32-bit and 768 kHz, native DSD512 and DSD256 via DoP. Coaxial and optical inputs sit beside USB and take PCM up to 24-bit and 192 kHz, without DSD. The line out delivers 2.1 Vrms at 0 dBFS from a 20 ohm source, with DAC SNR and dynamic range both at 122 dB, THD+N of 0.00015% at 1 kHz and crosstalk of -137 dB, with noise below 1.8 uVrms and channel balance within 0.3 dB. The headphone output is rated at 1800 mW per channel into 32 ohm, 900 mW into 64 ohm and 250 mW into 300 ohm, each below 0.1% THD+N, with an output impedance under 0.1 ohm. Maximum voltage swing reaches 21.5 Vpp at high gain, and the maker recommends headphones above 8 ohm. Case size is 165 x 120 x 40 mm.

Engineering and use context

Wireless reception comes from a Qualcomm QCC5125 chip supporting Bluetooth 5.0 with LDAC, AAC, SBC, aptX HD, aptX LL and standard aptX, and the set holds Hi-Res Audio Wireless certification. The internal converter of the Qualcomm chip is bypassed, and its digital stream goes to the ES9038Q2M instead, so wireless and wired sources share the same conversion path. The headphone stage is built on TOPPING's NFCA circuit and offers two gain settings of +6 dB and +19 dB, which covers both in-ear monitors and full-size headphones. Its noise floor is below 2.1 uVrms at low gain and 7.0 uVrms at high gain, and TOPPING quotes THD+N under 0.00015% at 1500 mW into 32 ohm and crosstalk of -90 dB. Frequency response is 20 Hz to 20 kHz within 0.3 dB and 20 Hz to 40 kHz within 0.7 dB. For the amplifier section, TOPPING lists 120 dB of SNR and 120 dB of dynamic range.

Pairing

In preamp mode the variable output feeds a power amplifier or powered monitors directly, with the remote handling level. In DAC mode an integrated amplifier accepts the fixed level on any spare input, and a phone can stream via LDAC.

Alternatives

The TOPPING D10s is a smaller USB-powered DAC from the same maker without a headphone stage or Bluetooth.