You might think vintage Fenders cost a fortune, and you'd be right: some of them do. But there was more to the company's output than Strats and Teles, and some of it can still be bought for a song.

JUST OFF THE Charing Cross Road in London's West End lies a short and grubby one-way street. It's called Denmark Street, and ever since the 1960s it's been a magnet for anyone interested in anything to do with guitars. Once you've discovered where it is, it's pretty hard to pay a visit to London without going to look at those half-dozen shops full of all those gorgeous, glossy instruments in 'Tin Pan Alley' - even though, in your heart, you know you're probably never going to be able to afford to buy any of them!

Imagine that you're standing there one afternoon, your nose pushed up against the glass, when your eye is caught by an old guitar. The white paint has been almost worn away, the metalwork is rusty, and the neck has been stained dark grey by years and years of hard use (and abuse). Aha! Now there's a guitar that's seen better days! Yet in an odd sort of way, it's got a certain something about it, a certain something that says... this is the guitar for me. Surely a guitar as tired and worn-out as this shouldn't cost too much?

You walk inside, go up to the man and utter those immortal words: "Excuse me, how much is that Fender in the window?" He rubs his chin thoughtfully, looks at you for a moment, then names a price so outrageously steep that you stagger backwards, struck by a sudden and severe attack of vertigo. You fell in love with the wrong guitar! That battered old thing was a 1957 Stratocaster, the instrument made famous by the incredible Jimi Hendrix, one of the best guitars ever designed and the most sought-after model that Fender ever made.

Not only that, but there's a strange mystique that surrounds any Fender made before 1965. For it was around this time that Leo Fender, his health deteriorating, gave in to pressure and sold the entire company, lock, stock and barrel, to the enormous CBS corporation - for thirteen million dollars. There's a general feeling that the later guitars weren't built nearly as well, and that the design changes CBS made were not necessarily for the better. So it's the "pre-CBS" guitars that command the big money.

If the man in the shop is in a good mood, he'll let you take the old Strat down and plug it in, just so you get an inkling of what all the fuss is about. The first thing you'll notice is how comfortable the neck is, then how good it sounds, and how much all-round "character" it seems to have - that indefinable certain something. You're on the way to catching the Old Guitar Bug, but how the heck can people justify asking that kind of money? Is it all a con?

Con or not, it's not necessary to rob a bank to satisfy your new-found cravings. All you have to do is accept that there aren't any undiscovered Strats hanging up in junkshops any more, and set your sights on something a little more realistic.

From the late '50s up to the present day, Fender included budget or "student" models in their line-up. Because these guitars have always lived in the shadow of their older and more desirable stablemates - the Stratocaster, the Telecaster and the Precision Bass - they can be picked up for considerably less money. Mind you, the vast majority of the cheaper guitars went to the American home market, so while not impossible to find, they're not exactly commonplace here.

Does "budget" in this case mean "not-so-hot"? Well, these days, if a famous manufacturer wants a slice of the beginner's market they employ a Japanese factory, or even an Indian or Korean one, to do the work for them. And although this doesn't have to be a recipe for disaster, such instruments rarely retain all the qualities of the original. In the '50s and '60s, however, this international approach was out of the question. So Fender's Musicmasters, Duo Sonics, Mustangs and Broncos were built alongside all the rest, by exactly the same people, and using largely the same materials. Economies had to be made, of course, but that didn't stop them being great little guitars.

The one in the picture might look rather like a baby Strat. But it's actually a 1963 Duo Sonic, identical to the Musicmaster in all respects but one - an extra pickup placed near the bridge. I spotted it just a few weeks ago in a local music shop, hanging on the wall and with £239 on the dangling ticket. It wasn't a lot of money, but it was more money than I had. So I volunteered my weird Hofner/Framus mongrel to the man in part-exchange, and - because large-bodied guitars are currently trendy and small-ish ones like the Duo Sonic are not - actually ended up with a straight swap. Which, considering I knocked up the mongrel from bits costing substantially less than a ton, made me a very happy man indeed.

Identification. You can tell this Duo Sonic is a "pre-CBS" guitar by the narrow headstock and by the so-called "spaghetti" Fender transfer, black-edged but gold or silver in the middle. It's also possible to tell at a glance that this guitar was made after 1959, because that was the year Fender changed the wood used for the fingerboard from pale, honey-coloured maple to a darker rosewood.

There's a serial number on the neckplate at the back which reads L06129, and L-series numbers ran from 1960 to 1964. You can't always trust the serial numbers on Fenders, because swapping the plate from one guitar to another can take less than ten minutes. In this case, however, the plate is original; after all, no dishonest person is going to put a valuable L-series number on a lowly Duo Sonic, when they could take it off the Duo Sonic, put it on a Strat, and pocket four or five times the dosh.

The final check for the date can only be made by undoing those four screws and taking the neck off. Fender had the convenient habit of stamping figures giving vital information on the very end of the neck, and in this guitar's case the figures read 9 APR 63 A34. The 9 looks as though it should be the day, but it's actually a code for the type of guitar the neck is intended for - in this case, one of the "student" guitars. April '63 is the date, while the letter A indicates a narrow neck. The 3A sign means that this guitar has a three-quarter scale length of 22", as opposed to the longer 24" version or the Stratocaster's 25½".

What good is a three-quarter scale length to anyone? Well, three-quarter scale means that it's exactly like playing a normal guitar, but with a capo on the second fret. Not too bad, eh? In fact, if you've got small hands you might find that with one of these, playing the guitar seems suddenly much easier. The one disadvantage is that bass notes aren't as clear as on a Strat, especially high up on the neck.

But the pickups sound wonderful: quite toppy and very clear, with all the twanginess your heart could desire. The neck itself is chubby by modern-day standards; many necks these days are so thin that they're only suitable for high-speed pyrotechnics, but these old Fender necks feel just as comfortable for jazz chords as they do for lead-work.

The Duo Sonic feels small and light to play, because although it's like a Telecaster in that the body has no bevelled edge to rest your arm on or waist-cut to fit against the body, it's quite a lot thinner.

In terms of general design, the Duo Sonic has two main drawbacks. The first is the bridge, which has only three saddles instead of six, so that a pair of strings runs over each one. Because thicker strings need a saddle set further back, this makes setting the intonation something of a compromise. And when changing strings, it's difficult to remember which of the many grooves to use. The second drawback is the way the jack socket is mounted on the front: give the jack plug a hard knock, and you'll crack the scratchplate. Whoops!

If there's one thing which decreases an old Fender's value, it's unoriginal paint. When I first saw this guitar, I thought I'd uncovered a rarity. A sunburst Duo Sonic, anyone? No such luck. Red, white and blue were the original options, and someone has covered the old white finish of this guitar with a brave attempt executed with three spray-cans. Funny thing is, it was done a very long time ago, and the usual fashion in the late '60s and early '70s was to turn sunburst guitars into white ones - the Jimi Hendrix influence again.

If you're a tremolo fan, your best bet would be not the Duo Sonic but the Mustang. This was introduced in 1965 and displays the wider headstock of the CBS years, together with several improvements, such as six individually adjustable bridge saddles and a metal plate for the knobs and jack socket. If you want to see one, just take a look at a Fine Young Cannibals video. The Bronco, probably the most affordable of them all, was the singlepickup version and usually came in red.

I'm happy with my Duo Sonic, though, unoriginal paint and all. It wouldn't be enough for someone to offer me a Stratocaster as a swap - it would have to be a very good Stratocaster. And by the way, if you walk past a shop and see a white 1950s Duo Sonic with a maple neck and a gold anodised aluminium scratchplate, for goodness' sake don't buy it. Just give me a call.