Chord Electronics Huei Phonostage

As the world of HiFi continues it's love of the good old analogue vinyl/record format - more people are beginning to realise that the choice of Phono Pre-Amplifier has a massive bearing on sound quality. The reason? - All cartridges have a tiny amount of output compared to every other component in a HiFi system so they require a phono pre-amp to not only boost the signal by a massive amount - but also to apply the RIAA equalisation curve that is part of the process to enjoy record playback.

The Chord Electronics company has introduced a next generation micro-processor controlled MM/MC Phono stage with compact dimensions (the same casework as their Qutest DAC) and plenty of gain and impedance settings to ensure fine tuning to get the best sound out of nearly any cartridge on the market. 

The innards of Huei are based on the company's high-end Symphonic phono stage, and show much of the same thinking in electronic design terms. “Noise is of course the primary problem to be solved when doing a phono stage, and musicality is also important – careless design leads to a dull and lifeless sound. My aim was to keep the fully balanced architecture of the Symphonic – plus the UK design, engineering and manufacturing – but make it more affordable. We've done this by a super-short signal path and our trademark build quality”, Matt adds. This phono stage uses a combination of discrete transistor and op-amp circuitry. “We use the most appropriate components for the task in hand”, he says. “It's a fully buffered design from input to output, and sports an internal switch-mode power supply that gets its power from the supplied mains adaptor.

There are two schools of thought for phono stages – one is to go ultra-minimalist with nothing aside from a power switch, and the other is to offer a welter of facilities, and in particular full cartridge load and gain matching. The latter approach is more flexible and future-proof but invariably leads to fussy switch-gear and a highly complex user-interface. That's why Huei uses a microprocessor-controlled front end and those pretty lights; the idea is to make the complex manageable. There are twelve settings for impedance matching [47k ohm (MM), 30 ohm to 47k ohm (MC)] and eight for gain [MM: 25dB to 35dB, 8-step user selectable; MC 48dB to 70dB]. There's also a subsonic filter giving -24dB per octave below 50Hz, via a Rausch Slope profile.

TECHNICAL SPECIFICATIONS

MM/MC phono stage

• Input Impedance: Moving magnet: 47,000Ω, Moving coil: 100Ω – 3,700Ω, 12-step user selectable
• Gain Range: Moving magnet: 21dB–42dB, 8-step user selectable, Moving coil: 49dB–70dB, 8-step user selectable
• Input Noise: 1.1nV/Hz
• Max Output Voltage RMS: 20v RMS
• Equalisation Response: RIAA Curve
• Equalisation Accuracy: +/- 0.1dB
• Frequency Response: RIAA Curve = 12Hz to 25kHz
• Rumble Filter: Rausch Slope -24dB per octave below 50Hz
• Output Impedance: 520Ω (resistive)
• Input Power Supply: 12v–100v to 240v 50/60Hz PSU
• Dimensions (H×W×D): 4.1 × 16 × 7.2cm