If you have spent anytime travelling on the Underground lately then you will have noticed the interesting and puzzling phenomena of the wired up individual who gets on and stands next to you with the personal stereo firmly clamped to head, the wires either disappearing into the jumper or a suitable bag or briefcase. This product of our times will then stand there with the earphones squeaking and clicking to an incessant Electro-Funk cassette which must be absolutely deafening to them by virtue of the fact that it is so noticeable to everyone else. If you have ever tried one of these devices then you will know that you can achieve quite a high sound level before becoming audible outside the head of the user. The hotwired pranny will then — under the influence of roughly the equivalent of being in the front row of a Michael Jackson concert — stand stock still with a completely impassive look on its face so as not to appear odd and out of character with the rest of the boring, bored sleepy impassive commuters. I have not yet encountered anyone with a personal practise amp strapped on, Les Paul around neck, practising the latest HM licks or Strat wielders picking out Sultans of Swing — but I s'pose it's only a matter of time!

We have had a spate of these personal hotwiring kits lately and the JHS model here presents some interesting refinements.

I won't go into the ins and outs of personal practise amps because you all know what they are about and it isn't the hardest concept to grasp anyway. This particular one comes from John Hornby Skewes and is in a metal box, of sensible size and gives you two distortion, two clean and one normal sound. You have switchable chorus and switchable delay each with an LED indicator. You have a pre-set depth control for the delay and stereo outputs. This amp boasts two inputs and a send-return loop for using it as an effects unit. There is a single flashing LED to indicate that you have plugged in your instrument and the thing is in operation. A plate at the back reveals a battery (sorry) of AA size batteries. There are eight batteries which makes you think that maybe the unit only consists of batteries, but there's obviously something going on because the sounds, upon having a go, are excellent. The plethora of 1.5V batteries also means that the unit will keep pumping it out for longer than yer usual PP3. You've got an external 6V power supply socket to power the beast — yes I know that eight 1.5V batteries add up to 12 volts — and that would lead me to suspect that we have two lots of four batteries connected in parallel to further prolong battery life — should last forever!

Let's have a listen — I forgot to mention that there is a position on the sound selector switch for a 440Hz tuning signal — that's 'A' to you, so once we've tuned up off we go. The 'normal' sound is pretty well that — normal: a fairly representative version of whatever you stick in with little or no (it's difficult to tell) compression. I think none, but I have been wrong! The clean sounds are superb — one gives you a very bright trebly ring and the other a good clean sound with added bass boost and a slight top boost. Both clean sounds have an excellent compressor which really does give you an authentic full production sound. I particularly like the compression on the Rock Box and would rate it as one of the best features.

The chorus is stereo and very nice: the sound sweeps about inside your head and is full enough. The speed is a little faster than I would personally set on a chorus but proves to be good after a bit of usage. The echo is very, very good and again, stereo. You have a preset control to set the echo but in all fairness I think that you need it set to maximum for practical purposes — maybe for recording you would back it off a bit but it's a good feature to have in any case. With a clean, compressed setting, echo and chorus you get a beautiful, full, swirling, produced sound and you cannot believe it when you take off the 'phones because you cannot hear a thing outside the confines of your nut!

A slider input gain control sets the overall gain and there is a box around the eight level which would lead me to think that this is the onset of natural distortion. Not so on a Strat but a Les Paul thickens up a bit at this point. The actual distortion settings are very effective, the overdrive giving a fair simulation of just that and the distortion having a particularly creamy quality to it — the thing really can sing! The 'phones are excellent and I have said before that I think that we owe the recent rush of 'personal' technology to the advancement in this direction.

I really like this one but have a criticism in that the terrific — the only way to describe it — sound does tend to fall off in its impact when you try to use it through an amp as an effects unit. It is a fact that the closer to the 'ole lug holes you get, the better the sound — listen to a good record on 'phones and it doesn't matter how good your stereo is, it'll sound better — and obviously a personal practise amp is designed for that purpose. The sound through an amp is by no means bad at all — but the echo and chorus aren't as stunning as they are through the 'phones.

I think that the best thing I can say in summing up is that I am going to buy the review sample myself. I rate it that highly, and not only because the price is just over £100. There are many of these units available but I think that the metal case, the sounds available — don't forget that you can have any combination of echo, chorus and clean (all on, all off, some, any, etc), and the built in tuning signal make this a very good buy. I'm having one and if you happen to be travelling on the tube and some silly old sod is posing and preening in the corner with a pair of 'phones and wine red Strat — it'll probably be me!

JHS ROCK BOX - RRP: £119