Rather a lot of technical hoo-ha, as well as typographical capitalisation, attends the Bravura electrostatic headphone from Warwick Acoustics. That’s not to dismiss as trivial the development work carried out by the Nuneaton company in the engineering of the Bravura. But all the technical smarts in the world count for nothing if the Bravura doesn’t sound any better than the competition, or at least deliver notable value for money.
And competitors there are. Not just electrostatic headphones from other vendors, of course, but a whole host of headphones using moving coil and planar magnetic drivers. The market for electrostatics being rather niche, there are many more of the latter than the former.
Confession time. I’m a fan of planar magnetic technology for headphones and, frankly, have been less than impressed by the electrostatics I’d heard to date; finding the undoubted plusses of characteristically low distortion and speedy detail offset by unconvincing low-end performance and an inability to play loudly, as one might wish to do with rock music, for example. With electrostatics there was always something missing. And so it was that I approached the opportunity to evaluate the Bravura with a degree of scepticism.
Warwick Acoustics have been ploughing an electrostatic headphone furrow for some time, and already offers the Sonoma Model One at £5,000 and the Aperio at an eye-watering £20,000. At both price points your money buys a proprietary system of headphone and dedicated amplifier/DAC. The Sonoma amplifier and headphone system is assembled in China while the Aperio amplifier and headphone are UK built.
Sharp-eyed readers will have registered the use of the word proprietary in the previous paragraph. In order to mitigate some of the constraints imposed by electro-physics, Warwick Acoustics employs digital signal processing in both amplifiers, and the response curves of the headphones are designed to match. The Sonoma and Aperio amplifiers will therefore only work with Warwick Acoustics headphones, and vice-versa.
So too with the Bravura headphone, which is designed to be partnered with the existing Sonoma amplifier. It’s an upgrade on the original Sonoma, embodying a further development of Warwick Acoustics’ High Precision Electrostatic Laminate that is claimed to result in a wider bandwidth, even less distortion, and the ability to generate higher sound pressure levels. If you already own a Sonoma Model One system you can buy a Bravura headphone for £1,700 and use it with your existing Sonoma amplifier. If not a complete Bravura system, including a Sonoma amplifier costs £5,500 if you opt for the silver finish and £6,000 for black.
The Sonoma amplifier is a rather handsome device, with a finish that speaks of quality. There are reassuringly chunky toggle switches front and rear for source selection and power, a volume knob on the front and indicator LEDs to confirm source and correct operation. The Sonoma can handle 32-bit/384kHz PCM signals as well as up to DSD128 via its USB socket, and 24-bit/192kHz PCM on its coaxial S/PDIF input. There’s also an analogue input via a pair of RCAs, and a 3.5mm input, presumably for portable music sources.
Inside it’s a Class A amplifier with an integral DAC, using a pair of ESS Sabre delta-sigma chips in mono mode. Both analogue and digital Inputs are sampled by an AKM analogue to digital converter chip at 32 bits, passed to the XMOS digital signal processor which operates at 64 bits, then down-sampled to 32 bits before being passed to the DAC chips. To be clear, this means everything – including the input from a phono stage should one be connected – goes through the DACs.
The Bravura headphone – at least in the review sample’s silver finish – has a standard of materials and build quality that is on a par with other headphones at or around the price point, although as already noted only some of the alternatives are electrostatics. Warwick Acoustics makes much of the fact that it weighs 403g (our sample was 410g). But that’s not a particularly low weight. Audeze’s current flagship planar magnetic headphone, the LCD-5, is only 9g more, and the electrostatic SR-007 MKII from Stax is 45g less.
More than ultimate weight, I have always found that earpad and headband design tends to make the most difference to comfort and in this respect Warwick Acoustics gets good marks; the Bravura is comfortable to wear for extended listening sessions, but it does exert a firm clamping force on the wearer’s head, presumably part of the design effort to achieve a better low-end response than that of most other electrostatic headphones. Once I had adjusted the headband for optimum fit the Bravura felt secure, but readers should beware; human morphology varies widely and so what I find acceptable may not suit everyone.
The lead that connected the review sample Bravura headphone to the amplifier was quite a bit stiffer than those of the Audeze and Sennheiser alternatives to hand. I found that it would not always naturally slump into a relaxed position in the way that most headphone leads do. Once I’d settled into the listening chair I found careful arrangement of the cable so that it didn’t exert an unwanted pull on one side of the head or the other paid sonic dividends.
The sonic characteristics of the Bravura headphone and Sonoma amplifier can be quite disorientating to listeners used to slower, more distortion-prone headphone technologies. Depending upon the quality of the head-fi chain you are used to, at first it might seem as if someone has turned up a hidden control labelled DETAIL; you might not only hear more micro-dynamic content than previously, but the delivery can seem faster, more pacey, with some transients, particularly percussive ones, rendered with a sharper leading edge. The extra detail also helps give the soundstage a particularly high degree of solidity. Performers have a rooted-to-the-floor quality, with the boundaries and nature of the apparent space around them also portrayed with uncommon precision. Warwick Acoustics’ amplifier/DAC design clearly imbues the Sonoma amplifier with very effective control of channel phase accuracy.
It’s hard to be sure whether all the non-negotiable processing done within the amplifier leaves an imprint on the sound or not. The Sabre DAC is ubiquitous and it’s obvious why Warwick would choose it as the D to A element of the Sonoma. The problem for the reviewer is that some Sabre characteristics – heightened detail resolution for example – mirror those claimed for electrostatic headphones. Which begs the question; when we approach the Bravura, what are we listening to? Is it the combination of ADC-DSP-DAC, which, I remind readers, converts analogue inputs to digital, or is it Warwick Acoustics’ clever electrostatic diaphragm technology? Whatever the answer, and common sense says it’s probably a combination of the two, the Bravura headphone teamed with a Sonoma amplifier certainly treats listeners to a compelling sonic ride.
It produces particularly vivid dynamic and spatial detail, if not the last word in SPLs; the Bravura’s revised High Precision Electrostatic Laminate may indeed be lighter and go louder than the previous form, but it still doesn’t make the Bravura a head-bangers’ headphone. To be fair to Warwick Acoustics, that’s not what the Bravura is about anyway. If we want rocking SPLs then we can buy a closed-back moving coil headphone and a meaty amplifier and knock ourselves out… and for not a lot of money either.
Curious to see how the Bravura would cope with harmonically very complex material I played the 2018 album Soar by Welsh harpist Catrin Finch and Senegalese kora player Seckou Keita. On the track Listen To The Grass Grow, Finch’s classical harp and Keita’s kora intertwine in a duet that is particularly rich in natural intermodulation – and no wonder, with so many strings in close proximity to each other. It’s a stiff test of amplification, speakers and headphones, able to highlight any tendencies towards poor control or excitability. The Bravura system gave it an uncommonly detailed reading, revealing finger-plucks on each instrument as separately delineated events, in conjunction with what might best be described as an almost pristine cleanliness in its transcription of the dense harmonics.
Some headphones that I have had through my hands in recent times have blurred things on the same track, giving an entertaining sound but one which tended towards the euphonic and homogenised. Through the Bravura I heard Finch’s concert harp with its richer than double-chocolate character to good effect, but the headphone also opened up the more reticent harmonics produced by Keita’s kora. That’s not an instrument that in the past I’d have credited with having much tonal richness, but the Bravura showed me otherwise.
I played the jazz favourite, Sunday At The Village Vanguard by the Bill Evans Trio, listening in particular for how the Bravura coped with Scott LaFaro’s bass. Warwick Acoustics claims a bandwidth of 10Hz to 60 kHz for the Bravura but doesn’t say how many dBs down it is at each extremity. I don’t have the kit required to measure the performance, but can report that the Bravura is able to reproduce stand-up bass fundamentals at 42 Hz with good power and articulation, and the left hand of piano at 27 Hz also, although I felt the latter marginally less convincingly.
Through the Bravura LeFaro’s bass was delivered with impressive speed and textural clarity, but marginally lower in the mix than I hear through my reference headphone rig, with the consequence that the midrange and on towards the top-end was given more apparent prominence. It is indeed this sweet spot that electrostatics are particularly renowned for and here the Bravura really delivers. Sanchita Farruque’s vocals on the track Immigrant from Nitin Sawhney’s album Beyond Skin provided one of those hairs on the back of the hand moments, so close and intimately did the Bravura transcribe her voice, beautifully pitched and modulated, almost luminous, simply dripping with heart-breaking emotion.
I have not heard an original Sonoma system, so it’s not possible for me to echo the head-fi commentators currently applauding the improvements in the key areas of loudness, bass extension and resolution achieved by Warwick Acoustics. Coming to the Bravura effectively cold, all I can do is treat it simply as a head-fi rig among many at around £5,000.
Unlike what we might term more conventional headphone amplifiers – in others words non-electrostatic ones – you won’t be listening to IEMs through the Bravura system or chopping and changing headphones at whim, and neither will you be using it as a handy desk-top pre-amplifier. But the Bravura avoids to a good degree the loudness and bass extension limitations that until now have tended to limit the market penetration of electrostatic headphones.
Warwick Acoustics have given us a mature version of the technology that, while it may not satisfy all potential buyers, can certainly now be considered a mainstream contender purely on its sonic merits.