Topping DX7s is a fully balanced, versatile and efficient DAC, preamplifier and headphone amplifier with USB, coaxial, optical and AES inputs, and RCA/XLR line out, coaxial, 6.35 mm jack and balanced XLR headphone outputs. It incorporates a symmetrical design based on two ESS ES9038Q2M SABRE DAC chips, 2nd gen XMOS XU208 USB interface, four Texas Instruments OPA1612 operational amplifiers and two Texas Instruments TPA6120 headphone amplifier chips, all these components guarantee extraordinary, high fidelity playback.
DX7s is designed fully symmetrically. When connected via USB, signal is first handled by a second generation XMOS XU208 USB interface, well known to audiophiles and offering an exceptionally transparent sound. XU208 chip is a representative of the xCORE-200 Series by XMOS and is a 32-bit mulitcore microcontroller characterized by its low latency and timing determinism. Unlike conventional microcontrollers, XU208 is cabable of exectuing multiple real-time tasks simultaneously and communicate between tasks using a high speed network.
From there signal is separated into four channels to create a fully balanced transmission, this is done by two ESS ES9038Q2M SABRE Reference DAC chips that are a very high-performance, 32-bit, Stereo audio D/A converter designed for audiophile-grade equipment. Using the critically acclaimed ESS patented 32-bit HyperStream™ DAC architecture and Time Domain Jitter Eliminator, the ES9028Q2M SABRE Reference DAC delivers a DNR of up to 129dB and THD+N of –120dB, a performance level that will satisfy the most demanding audio enthusiasts. The ES9028Q2M SABRE32 Reference DAC’s 32-bit HyperStream™ architecture handles up to 32-bit 384kHz PCM data via I2S, DSD-22.6MHz data as well as a mono mode for highest performance. The ES9028Q2M SABRE Reference DAC sets the standard, SABRE SOUND, for HD audio performance. It benefits from unprecedented dynamic range and ultra-low distortion, unmatched audio clarity free from input clock jitter and distortion-free signal processing.
Then the signal moves to the analog stage where it is amplified by four Texas Instruments OPA1612 dual bipolar-input operational amplifier chips (two per channel). These op amps achieve very low 1.1-nV/√Hz noise density with an ultralow distortion of 0.000015% at 1 kHz. The OPA1611 and OPA1612 offer rail-to-rail output swing to within 600 mV with a 2-kΩ load, which increases headroom and maximizes dynamic range. These devices also have a high output drive capability of ±30 mA. They are unity-gain stable and provide excellent dynamic behavior over a wide range of load conditions and they feature completely independent circuitry for lowest crosstalk and freedom from interactions between channels, even when overdriven or overloaded. They benefit from their ultra low noise and distortion, high slew rate and wide bandwidth to produce a superior sound quality.
The headphone amplifier section is built around the Texas Instruments TPA6120 high fidelity headphone amplifier chips. The TPA6120’s current-feedback AB amplifier architecture delivers high bandwidth, extremely low noise, and up to 128dB of dynamic range. Three key features make current-feedback amplifiers outstanding for audio. The first feature is the high slew rate that prevents odd order distortion anomalies. The second feature is current-on-demand at the output that enables the amplifier to respond quickly and linearly when necessary without risk of output distortion. When large amounts of output power are suddenly needed, the amplifier can respond extremely quickly without raising the noise floor of the system and degrading the signal-to-noise ratio. The third feature is the gain-independent frequency response that allows the full bandwidth of the amplifier to be used over a wide range of gain settings. They provide maximum of 1000 mW x2 at 32 ohms and 546 mW x 2 at 300 ohms via the four-pin XLR balanced out.
On top of that Topping DX7s uses customized drivers (for Windows 7 and above) from Thesycon, that combined with the above electronic components allow DX7s to support high sampling rates: PCM up to 32bit 768 kHz and DSD up to DSD512 Native.
Overall DX7s barely colors tone and offers a very faithful reproduction, with very low distortion and great linearity. Music gains in dynamics, details, neutrality.