July 2017


Rupert Neve Headphone Amplifier RNHP
Martin Colloms Assesses a headphone amplifier from one of pro audio's most famous names.
Review By Martin Colloms

  Rupert Neve is a very well known name in studio equipment design and manufacture, especially components for those eponymous analogue mixing desks over 40 years ago, used on countless invaluable LPs. He himself is now 90 years old, and began in audio nearly 80 years ago! Although his original Neve company was sold way back in 1973, he’s currently involved in Rupert Neve Designs, which operates out of America as a relatively new company specializing in studio plug-ins.

Although most of the components produced by Rupert Neve Designs are essentially Pro-oriented, this £469 ($549) RNHP headphone amplifier is more of a crossover product that will appeal to both professional and domestic consumers. Indeed, while the prime UK distributor is the Pro-oriented Sonic Distribution, our supplier of the US-built RNHP was Russ Andrews, and its price included free UK mainland delivery. It is covered by that company’s 14-day home equipment trial and 12-month warranty.

The description notes a high-power, high-headroom design for driving up to high-impedance (600 Ohm) headphones, combined with a near-zero output impedance: less than 0.1 Ohm is claimed at 1kHz, via the direct-coupled, current-feedback Texas Instruments chip amplifier. XLR or TRS inputs (for balanced professional devices) are partnered with an RCA / phono pair, the latter calibrated for -10dBV signals and selected with the ‘B’ switch. A 3.5mm jack input is also fitted and is ‘specifically calibrated’ to work with mobile devices like phones, computers and digital cameras.

The external plug-top switch-mode power supply operates at 24 Volt, 6 Watt DC, but the unit may also be powered using a 24V, 250mA rated battery (not sold by Neve). Output powers are quoted as typically 300mW into 44 Ohms, 230mW into 16 Ohms and 175mW into 150 Ohms, which are considered to be representative load values.

Maximum voltage is 5.1V into 150 Ohms, from a very low output impedance of 0.08 Ohms. The claimed wide frequency response is 10Hz to 120kHz (+/-0.2dB) with typical (and confirmed) signal-to-noise ratios of better than 100dB. It uses a steel clamshell chassis fitted with shock-absorbing rubber feet, measures 16.5 x 4.8 x 11.7cms (WxHxD), and weighs 0.93 kg.

Recommended
Inside, a full size, Pro-grade PCB is neatly laid out and has classic audio NE5532 Op-Amp integrated circuits at the input, an ALPS Blue volume control, and the well established Texas Instruments integrated circuit 6120 headphone power amp (now over 12 years in service).

Sound Quality
Sounding rather bright and brash when first powered up, it was therefore run in for a few weeks to give the sound a good chance to settle down. One issue was the plug top power supply, which did slightly impair system sound quality, due to the usual residual switch-mode power supply interference. That said, it subsequently settled down to some degree, sounding tonally better balanced and exhibiting crisp and powerful transients, coupled with impressive low level detail. It has a good grip on dynamics and was both expressive and expansive, the latter relating to the large scale stereo images which were heard. Backgrounds were silent and it could play very loudly into numerous types of headphones from planar magnetics to higher impedance moving coils.

On the debit side, a hint of grain and sibilance in the mid treble was audible, and the soundstage was presented a little nearer than usual. The sound quality might have had a little more rock and swing, as they sounded a little detached from the primary rhythm lines and not quite as convincing in beat, weight or perspective as the venerable (albeit 20% more costly) Lehmann Linear.

Conclusions
This sturdy well built design offers a good performance with versatile (albeit all analogue) input and output facilities. It is powerful, noise levels are low and it will drive a wide range of headphones types and therefore deserves Recommendation.

Specifications
Type: Solid-state headphone amplifier
Maximum Input Levels
"A" XLR I/P: +22.8 dBu @ 1kHz
"B" RCA I/P: +14.7dBu @ 1kHz
"C" 3.5mm I/P: +3.3dBu @ 1kHz

Output Power:
As measured with typical headphones, Z=44 Ω: 3.617 VAC RMS @ 1kHz = 300mW RMS
16 Ohm typical Load: 1.933 VAC RMS @ 1kHz = 230mW RMS
150 Ohm typical Load: 5.108 VAC RMS @ 1kHz = 175mW RMS

Output Impedance
0.08 Ohm @ 1 kHz, 16 to 150 Ohm load, 0dBu input

Frequency Response
+/- 0.2dB from 10Hz to 120kHz

Noise
Measured with typical headphones, Z=44 Ohm, BW 22Hz to 22kHz
"A" XLR Input: -101.9dBV,
"B" RCA Input: -100.9dBV
"C" 3.5mm Input: -88.8dBV


Dimensions: 6.5" wide x 4.6" deep and 1.9" (WxDxH)

Power Supply Requirements
24VDC @ 0.25 Ampere (6 watt) minimum. Use with supplied power adapter, as this has been carefully selected for best output power and noise performance. May be used with a properly configured 24 Volts battery as well.

Price: $549

Company Information
Rupert Neve Designs, LLC
P.O. Box 1969
Wimberley, TX 78676

Website: www.RupertNeve.com