Vertex AQ JSA for headphones: VERTEX ON EAR

2nd January 2016

Normally focused on combatting distortion within a normal hi-fi chain, Vertex AQ has now targeted the popular headphone market. Paul Rigby reviews the JSA

The headphone market continues to boom and prosper with headphones (on ear and in-ear), headphone amplifiers and a host of accessories sprouting from the left and right with an ever increasing rapidity. I have to say, though, that this is the first time that I have come across a passive headphone conditioner targeted at both microphony and RFI.

The system arrives in two bits. The most substantial part is a sturdy metal box. Inside is an enhanced acoustic absorption labyrinth, solid-core silver conductors and unbleached cotton insulation. You can also buy a cheaper model without the solid core conductors and a standard labyrinth. Similarly, I tested the super jack lead (Type 2) featuring a solid core silver conductor with EMI absorbent tubing but you can also buy a cheaper Type 1 tube with silver-plater copper conductors and PTFE insulation.

In action, you plug the jack lead into the JSA and the other end into your headphone amplifier. You then plug your headphones into the JSA.


Spinning the Dexter Gordon CD, I Was Doing All Right and listening to music through headphones, via the JSA, reminded me of the sonic improvements heard via the Vertex AQ power cables and blocks reviewed elsewhere (see that review for a more in-depth explanation of the technology used within the JSA). In fact, the improvements are almost exactly the same which says a lot for the consistency and the technological direction of Vertex AQ’s research and development.

As soon as this jazz track began, there was a smoothness to the overall presentation, a lightness and clarity over the entire soundstage. As the sax solo appeared, it too adopted the smooth nature of the rest of the ensemble but, when power was applied by Dexter Gordon, the reedy nature of the sax itself became more apparent. There was obviously vibrational sound occurring around this instrument. When, eventually, the trumpet solo appeared on the other channel via Freddie Hubbard, the most noticeable aspect of the improvements were an increase of both air and space. The trumpet sounded like it was being played within a larger area, increasing the amount of available reverb and the tails from that reverb.

I turned to vinyl and rock via The Who and Going Mobile from the album, Who’s Next. Featuring a high energy rhythm but with the slightly more fragile Pete Townshend lead vocal, the most obvious initial difference was centred more on, drummer, Keith Moon’s performance as the early cymbal crashes were just as splashy but far more controlled. Previously, the treble-infused cymbals splattered and scattered the cymbal sound. The JSA corralled the splash into a more focused area. This focus was also allied to Townshend’s vocal which was smoother and purer in tone. His acoustic guitar also now sounded like a group of strings instead of a homogenous noise.

Moving to the mono vinyl edition of Bobby Darin’s Venice Blue, the entire track appeared to have tightened up and to have improved in terms of clarity. That is, the tight guitar strum had a reflective, rather shiny effect instead of the previous dull sheen. Cymbal effects had a definite ‘ting’ where before there was none and the strings swept over the soundstage rather than being sluggish and lumpen. In short, the timing of the instruments had improved throughout, Even the bass was now rounded in form with a more interesting personality, while Darren’s vocal adopted a 3D effect, moving away from the backing instruments.


No doubt using the same technology to its respected Vertex AQ distortion removing cables, filters and power blocks, the JSA clears a lot of the rubbish from a packed soundstage, giving it room to perform and relaxing all of the artists. Instead of a heightened tension, singers and players now seemed to be enjoying themselves. Listening to the JSA, you will too.


JSA – TYPE 1 – £200

JSA – TYPE 2 – £320 (silver finish, gunmetal is £340)

JACK LEADS: Standard is £66 for 1 metre while the Super is £260 for 1 metre.

Tel: 01554 759267


Good: focus, transparency, upper mid detail

Bad: nothing




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