Historically there are two ways out of the ghetto. You have to be a sports type, or a musician. So why is it that the latter sensitive weed has to heave the equivalent of a weight-training programme in and out of the garret? Is this the Suffering required for Art?

The first solo trip carrying this amp from car to flat via three flights of stairs was a noisy, grunting affair, enthusiastically supported by local dogs, but it wasn't actually as devastating as anticipated.

The Sherwood is about the size of a single-drum top-loading washing machine, allegedly weighs a mere 54 pounds, and comes in the sort of brown that features in special offer luggage sets. It has one very uncomfortable handle on the top, no wheels, stacking corners, and looks unprepossessing and awkward.

All of which may be perfectly tolerable because it sounds superb.

Construction is chipboard. The amp compartment is separated from the open-back speaker section. The pre-amp and tone circuitry is mounted on a single flanged plate mounted from the front; the power amp, power supply and mains transformer are mounted on a similar plate from the rear. The 19in Accutronics reverb spring is mounted on the compartment floor between these two sections, well isolated from the speaker. Initial gain on the guitar input is from a 4558, and on the mike input a TL071.

Servicing access is dead easy, PCBs are clean, nicely laid out and solidly mounted, and the solder can be got at without further disassembly. There was only one sign of tooth-cutting on the review sample – an extra capacitor tacked on to the solder side of the pre-amp PCB. The power transformer looks to have a 120 volt tap available if you're thinking of lugging one off to foreign parts.

Carlsbro have designed this primarily as an acoustic-electric amp, with an extra mike channel with balanced and unbalanced inputs. As many of us have found out the embarrassing way, a piezo-bugged acoustic requires an amp with a fairly flat response. The usual guitar amp has lumps, bumps and dips across a limited frequency range that play hell with an acoustic. It is unfortunate for the less fit among us that a good flat full range sound currently seems very dependent on speaker size. It's here that the Sherwood's unnamed, flared-cone 15in and bullet tweeter produce the sort of starting point flat sound that I thought I'd never get outside a studio or a good hefty PA rig.

The guitar channel has bass and treble controls with maximum effect at 50Hz and 6.5kHz respectively. I don't think I quite believe the plus and minus markings on the panel, and these functions are not thoroughly defined in the "Instruction Guide" (their tautology). Zero sounds a mite boosted to me, and I would put flat somewhere in the minus – but I don't have a few grand for a frequency analyser. Cabinet, speaker/horn and passive crossover characteristics could well account for a very minor point. The really useful weapon is a limited "parametric" with a claimed plus or minus 20dB from 75Hz to 1kHz. There is no width control, and set width is not specified, but it sounds quite tight and proved effective enough to nail a low frequency feedback problem that has kept my D12-35 Martin confined to a cupboard for a few years. That's fitted with one of the old screw-on Barcus Berry's, hardly up-to-the-minute technology. But this guitar is now reprieved from threat of sale for practical as well as sentimental reasons – in this amp it works a treat.

My Ovations sounded very good indeed in it, and with a boost on the bass, a touch of treble on a wood-top one, and a discreet dip around the 700Hz mark to take out a crusty edge on one Adamas, the tone had enormous depth and space in it. I don't use the Ovation pre-amps with filters at 800Hz and 1200Hz by the way, so I'd expect roughly similar results from a few other bridge pickups. The clarity was quite marvellous, treble strings and artificial harmonics sang out in the muddiest pieces, and I found a real sense of volume of sound rather than scrunched-up loudness.

With a 90 watt rating, the Sherwood will happily go over the top for small rooms/clubs, cope with small theatres, and should be ideal on a festival stage.

I've one or two quibbles on the extras. The DI out and 500mV line out are both affected by master volume – I'd prefer it if they were affected by channel controls only which would make the unit more versatile for monitoring when hooked up to a big PA. I didn't experience any undue earth loop hum problems with the DI, but have yet to try it into a big rig. The effects loop is post-reverb, so if you want to use reverb to soften echo repeats, the echo must go before the input. I'm not sure of the value of an effects loop anyway. I don't know anyone who uses it, but am assured by various salesmen that it is a desirable feature. The reverb is first class, a good spring properly driven.

As well as the push/push reverb buttons on the control panel, there is a noiseless footswitch which may be useful for taking out the reverb for announcements between numbers.

Gigging this as guitar amp and PA for a solo act is quite feasible. Personally, I'd be happy to swap the switch for flip-out handles on the side even if it does have a nice little red light on it.

Side handles and wheels are sacrificed to a jealous God, namely the £300 retail ceiling. The makers consider that under that level, a footswitch and plastic travel cover are more desirable. I take their point, but guess that they don't have to carry it into a gig or worry too much if their barres are knackered for an hour after.

One important point. The internal speaker must be disabled by inserting a stereo jack in the headphone socket before hooking up extra speakers as the loading is right on the limit. I don't see the point of having an extra speaker facility – the sound is perfectly good as it stands. Understanding and sympathising with the Brit tendency to consult an instruction book only after something has gone bang or fizzled out, I think this warning should be on the back panel in BIG LETTERS right by the speaker outlets. Or the facility should be scrapped. The note concerning this point was on page four of my instruction notes guide explanatory manual. I know people who could burn a house down before getting to page three, and then they'd only be looking for a nude.

The unit has a keyboard application as well, and a couple of them could form the basis of a nice little stereo PA, but those aficionados of the DI'd Strat (pace CBS Fender) sound will love this rich, sparkling clarity with enough welly in the razor top end to Van Gogh the drummer's ears.

One of the amp's delights for me has been the ability to use outboard eq in a more literal and positive sense without having to second-guess a jagged combination of amp and speaker characteristics. Dealing closer to real dBs and frequencies rather than suck-it-and-see stuff has been revealing. I can hear things I'd given up for lost on stage – the tone of a pull-off, for instance, or the breathiness of a soft attack. Response is all there right across the range, from gut-shaking thumb-fleshed bass lines to the remotest stratospheric (pace CBS Fender) harmonic.

As the Ovation pickup was once a personal technical answer to some musical problems, so the Sherwood is an answer to the problem raised by the Ovation pickup. That is, what the hell do you plug into for general gigs?

To sum up, it doesn't look much, is a bit of a pig to cart about, but my oh my, what a sound. Try one and listen to your nail varnish.

Carlsbro Sherwood electro-acoustic combo: £291