v40 Blackline amplifier From Blue Aura 

9th February 2018

Looking for an all purpose amplifier that spans very little space? Paul Rigby offers one candidate as he reviews the Blue Aura V40 Blackline

It wasn’t long ago that I reviewed the rather excellent amplifier from Parasound, the Halo. As good as it is, though, it’s a hulking great thing. And many other amplifiers follow suit. If they aren’t quite as big they still take up quite a bit shelf space. Not everyone wants or can afford to dedicate so much area for a hi-fi chain.

Trouble is that smaller amplifiers are often small because they lop off quality components, features and more. There is often a price to pay for the compact form.

Blue Aura has attempted to offer both a small size with sound quality while retaining a healthy feature count with its v40 Blackline.

Blue Aura Blackline v40 amplifier: Valves and Bluetooth 

Offering a ‘valve’ amplifier (in truth, a valve pre-amp running a solid state amplifier…a hybrid then), it spans 148 x 264 x 215mm and weighs in at 3.5kg. It is, therefore, dinky and clean in its layout and rather lovely to look at. It even offers rack-type grab handles so that you can lift this <ahem> beast of an amplifier plus a protective valve Perspex ‘shield’ in case your hand wanders towards the hot valves. Those valves include two European-sourced ECC82 tubes plus a 6e2 indicator valve that shows the volume level: a nice touch. Behind the valves are two toroidal transformers that push out the claimed 30W.

The V40 Blackline Class A/B amplifier, offered in black or walnut, also features a DAC (handling just 24bit/48kHz as a maximum output) plus Bluetooth support (via a screw-in aerial that fits on the rear) that handles the aptX codec. Also on the rear are the speaker connections, power socket, sub out, mini-USB port for the DAC, a 3.5mm mini-Aux socket and a pair of RCA ports. So this amplifier is designed to support a relatively simple hi-fi chain.

Swinging back to the front of the chassis, you’ll find two rotary selectors for volume and the source. The on/off toggle switch is, rather oddly, placed on the top of the chassis, in the near left hand corner. An alternative control method is the credit card-sized remote which I can see being lost after about five minutes use. So how does the v40 perform?


I began with the vinyl version Public Image Limited’s Public Image from their First Issue debut LP. This track offers high energy dynamics with plenty of sonic contrasts from a high-pitched lead vocal to a sub-bass bass guitar.

The V40 Blackline coped well with these contrasts providing a clear, low noise response. The vocal, for example, combined admirable diction and a wealth of emotion with the useful addition of vocal reverb tails as an added bonus.

Blue Aura Blackline v40 amplifier: Valves and Bluetooth 

For some amplifiers in this price area, midrange can be a problem, suffering in terms of insight. Some competing designs could  be described as muffled or veiled. The low noise approach of the Blackline opened up the mids, though, adding space to the guitar attack, giving it a rhythmic and flowing aspect with enough detail to involve the ear while the drum strikes also added new and enhanced reverb. This made the drums sound large and dynamic, enhancing their impact and power.

Blue Aura Blackline v40 amplifier: Valves and Bluetooth 

Bass response was good, enhanced by that low noise performance, the v40 cleaned up the lower frequencies and provided new character and form.

The sense of clarity was confirmed with the CD version of Nancy Wilson’s jazz infused You Got Your Troubles. The transparency that surrounded this track gave the Wilson vocal performance a fresh and spacious aspect while the backing orchestra benefited from enhanced instrumental separation allowing, for example, the busy brass section to be separated from secondary percussion such as the tambourine. There was no midrange smearing here which meant that each instrument was able to present itself in a concise and detailed manner without masking from its neighbour.

Blue Aura Blackline v40 amplifier: Valves and Bluetooth 

Moving to Bluetooth, I played an AAC version of Mercy Mercy Me from Marvin Gaye. Much of the musical information is stripped from this lossy format to enable it to fit into a small space. Hence, high quality hi-fi that plays lossy files too well is actually not always a good thing. They only end up illustrating why lossy files are poor in the first place. Hence, any Bluetooth transfer of a lossy file has do be done with a certain gentle care. That’s what the v40 does here, giving the song a smooth and approachable playback. Gaye’s background instruments were fuzzed out just a touch to retain detail but not to make that detail too precise. Even bass offered a gently rolling beat that kept the track moving without grating at all while Gaye’s vocal was both easy on the ear and admirable in execution.

The V40 had accomplished so much to this point of the review so I was disappointed to see such a low specification connected to the built-in DAC. Nevertheless, I fed Andrew Gold’s song, Hypothetically, through it via my Red Wine-modded Astell&Kern AK120 DAP to test the v40’s DAC abilities.

Blue Aura Blackline v40 amplifier: Valves and Bluetooth 

Within the DAC’s limited resolution options, I was most impressed. A broad soundstage was coupled by a nicely constructed layering between the vocal and the backing instruments to produce a smooth midrange that produced enough insight to reveal appealing guitar string picking along with, in the treble area, delicate cymbal taps. All of this was allied to a well balanced bass response.


The v40 Blackline, apart from being a bit of a ‘looker’, is nicely put together and, for the heart of a simple hifi-chain for a beginner or as a second system, the amplifier is more than ideal as it supplies all of the features you’ll need to produce music of various types from a host of sources.


Price: £449

Website: www.blueaura.co.uk 

Tel: 01480 477738

GOOD: looks, feature rich, general sound quality, small footprint, Bluetooth performance

BAD: low resolution DAC, remote



Rega Planar 3

Trichord Dino phono amplifier

Cambridge Azur 651 amplifier

Spendor A1 speakers

Tellurium Q cabling

Blue Horizon Professional Rack System

Harmonic Resolution Systems Noise Reduction Components

All vinyl was cleaned using an Audio Desk’s Ultrasonic Pro Vinyl Cleaner