Chord Electronics Quartet upsampler introduced

According to Swedish publication Ljud & Bild's report, Chord Electronics has launched its new upsampler called Quartet. The device enters the signal chain before the D/A converter, converting digital audio to a higher sampling rate. Chord states that this corrects small but significant transient timing errors in digital playback. The company describes the product as the most important advance in the field of digital audio in its history.

Which features stand out?

At the center is the Blackbird WTA (Watts Transient Aligned) filter, developed by Rob Watts. The filter operates with four million taps; in its predecessor M Scaler, this number was one million. Chord states there is a ten-fold improvement in transient timing sensitivity compared to the previous generation WTA filter. Computation is performed by five Xilinx FPGAs. According to the company, this is five times the processing power of the DAVE DAC. Filtering is performed directly in hardware without converting to frequency data.

The Quartet contains Chord's first built-in A/D converter (Pulse Array). Thanks to two RCA inputs, analog sources such as turntables can also benefit from upsampling. The device consists of two chassis: one houses the signal electronics, the other the power supply unit designed by Watts. The Quartet works with all Chord D/A converters, but is primarily designed for DAVE.

• Filter: Blackbird WTA, four million taps
• Digital inputs: 2 × BNC (or dual BNC), 2 × optical, 1 × USB-B (galvanic isolation)
• Digital outputs: 1 × optical (192 kHz), 1 × S/PDIF, dual BNC (768 kHz)
• EQ: 108 bit, ten bands (shelf), ±18 dB
• Delay adjustment: from 10 milliseconds to three seconds
• Dimensions (H×W×D): 7.8 × 33.5 × 15.2 cm (power supply unit the same)
• Colors: Argent Silver, Jett Black

Price and warranty

The Quartet is handmade in the United Kingdom and comes with a five-year warranty. Swedish price is 345,000 kronor. The Choral Ensemble Stand is sold separately. According to the source, the product can be heard by appointment at Akkelis in Gothenburg.

Why does it matter?

The Quartet brings a different approach to upsampling and time alignment for digital source chains using DAVE; it can also pass analog inputs through this process. The performance claims are from the manufacturer; there are no independent measurements in the source text.