The latest from Marshall is a 15 watt all-valve combo, aimed at the recording player who demands a genuine 'valve sound'.

Something that many serious (usually professional) guitarists have long been crying out for is a new amp that lets them get the true valve guitar sound of a large pro-quality head/cab, but in a package suitably small enough to use for recording, and easily transportable in a car or taxi. In the absence of a new amp suitable for the job, a lot of players resort to tracking down ancient Fender Champs or even older valve Gretsches, Gibsons and suchlike to fulfil this role. Of course there's nothing to stop you using a large amp in the studio, but the 'everything on full' loudness is often too much for comfort, which leaves you with only a pre/post master volume set-up for your solo sound, rarely a 100% satisfactory solution as no master volume system that I've yet encountered has ever sounded quite as good as a valve amp running at full belt.

Unfortunately, the laws of production economics count against a small valve amp of this type. However it's tackled, a studio-size valve amp uses many identical components to a stage-size unit, and this makes the price difference between a mini and a maxi amp seem uncomfortably close. However, if you really need this sort of specialised product, that's a fact you're going to have to live with.

It's probably the inevitably high selling price of a small all-valve amp that has deterred most manufacturers from attempting to cater for this need, so hats off to the Milton Keynes Marvels - Jim Marshall Products - for having thrown such cautions to the wind with their latest all-valve combo, the Studio 15.

The Studio 15 is every inch a Marshall product - built with an attention to manufacturing quality, quite regardless of the usual compromises made to knock a few pence off the selling price of a mini-amp. The all-wood cabinet is equally as tough as those on their stage-intended amps, and is wrapped in the usual Marshall-quality vinyl, with a cloth speaker grille. Corner protectors and a tough carrying strap complete the bill.

Designed for studio use, every facility on the Marshall has been carefully thought-out. The back panel, for example, features not only the usual jack sockets for the onboard and extension speakers, plus a line-out feed to ancillary equipment, but also an XLR which gives a feed output suitable for direct feeding to professional recording mixers, where such a feed is more or less essential. Cleverly, this output also uses a 'floating' system, doing away with the need for removal of earth leads (never a happy situation when it has to be done). Being balanced, it also provides a hum-loop-free send to the mixer. Also on the Marshall's back panel are a standard IEC detachable mains connector and a headphone socket, the latter providing the insertion of a dummy load when connected, thus muting power to the speaker, whilst it feeds the cans - likewise when the D.I. is used.

The Marshall's front panel provides a sensible minimum of facilities: a single jack input, pre amp gain, treble, middle and bass controls, a standby rocker and an internally illuminated mains on/off switch.

Inside, the all-valve Studio 15 is a true Marshall. I've remarked before how beautifully this manufacturer's equipment is made, and, albeit a mini amp, this newcomer is no exception. The single speaker inside the open backed cab looks at first sight like a standard Celestion 12" - but it isn't. In fact (IT's spies tell me) it's the result of Marshall's insistence on getting a sound from a modern small speaker which resembles that of the old (and much loved) G12-25. I'll comment on the results of Celestion and Marshall's deliberations later on.

Test no. 1 for any amp intended for studio use (especially a valve amp as they can be a bit noisy, it must be admitted) is the hum level. Here the Studio 15 passes with flying colours, being almost spectrally quiet. Even the effect of the passive tone controls is minimal from a noise angle, although not in respect of intended functions.

As this is every inch a true professional's amp, I didn't trouble it by jacking in a cheap guitar. When you're dealing with professional class valve amps, there's a tendency I've noticed before for some of them to be unforgiving of poor guitars and their pickups - in fact such instruments will often sound better with a cheapish transistorised amp, a high quality valve unit exposing their weaknesses unmercifully. Sticking to a fair (and likely) quality match, therefore, I tried my Gibson SG first. The result, with the master volume high and the pre-gain low, was a sound so sweet, warm and clean that it curled my toes and brought tears to my overdraft! On the neck pickup the subtly expressive dynamics of the Gibson were extracted and reproduced perfectly by the Marshall, Jazz chords sounded warm and touch responsive, with not a trace of muffling or masking of the guitar's richness in this setting. Flipped over to the bridge humbucker, however, the Marshall began to bark into an aggressive, attacking life. Still set clean, the Gibson rang and 'talked' with every nuance of the harmonics audibly there.

Winding up the pre-gain gives that characteristic, unequalled vintage Marshall sound. Run at full power (when it's astoundingly loud for a 15 watt amp!) the Studio 15's valves give that touch-responsiveness to the way your fingers and pick handle the strings, a quality allowing you to play exactly what you feel, from the raw aggression of a jagged rhythm chord, to a sweetly sustaining solo barely held on the edge of runaway feedback.

I had just one worry about the Studio 15 before switching over to a Strat. To get the Gibson really singing, I'd had to have the pre-gain on maximum - not something which I'm used to with the high-ish output of the humbuckers, and this made me wonder if the lower power of the Fender's single coil pickups wouldn't be enough to drive it sufficiently hard for perfect overdrive. Having said that, the resulting sound from the Strat was fine and sharp - perfectly capable of extensive sustained soloing.

Curiously, passive though they are the Marshall's tone controls work really well, offering not only a great range of sounds but also a 'class' which I just cannot find the right words to describe. In conclusion - yes, the baby Marshall is just what a lot of recording players are looking for. The crystal clear non-overdrive sound, the natural warmth and responsiveness of the distortion, are excellent, and when recorded the sound is uncannily like that of a full-blown stage amp, only minus the hum. Equally, this amp could well suit a dual role. Not only will it shine in the studio, but you could very satisfactorily use it as the first unit in a stage amp chain. It would do perfectly in this role.

If I had any doubts at all about this latest Marshall then they would relate only to any player who wanted full 'overkill' distortion from guitars with weak pickups. Some lower output Strats, and a few other Fenders (notably Jags) could encounter trouble overdriving this amp. On that account perhaps a little more pre-amp gain might help some players? In fact, I wouldn't have minded just a shade more myself. Nonetheless, I quibble. Session players who hate transporting huge amps, anyone who wants a genuine 'vintage' big valve sound from a small amp will probably find this the very amp they've been waiting for. Over £260 might like a lot of money for a small amp - but not once you've heard it!

Marshall Model 4001 'Studio 15' Valve Combo RRP £267 Inc. VAT

More details from Jim Marshall Products Ltd., (Contact Details).