The British Amp Invasion: Birth of the Crunch

Editor's Note: The following excerpt comes from chapter five of acclaimed guitar author Dave Hunter’s latest book, The British Amp Invasion. You might remember Dave from his Reverb series "Dave’s Corner" that saw him explore the many intricacies of guitar and amp tone. For the remainder of this story and more fascinating tales from the British amp history, you can order Dave’s book right here on Reverb.

British guitar amplifiers of the decade-and-a-bit from 1959 right through the 60s were all about making it louder. The need had been clearly identified, vocalized by players themselves, and was being addressed by several prominent British manufacturers. None, however, established BIG quite so resolutely as did Marshall.

Having started merely as a retailer selling amps made by others, Jim Marshall saw the need for a bigger, louder, professional-quality amp with the ready availability and accessible pricing that only a home-grown effort could provide as the incentive for his ‘let’s build it right here!’ approach. And if the firm took a couple of years from the fledgling efforts in 1962 before the Marshall sound was fully established, it was certainly headed in the right direction from the very start.

Kinky Distortion

Even if it was a no-no in the studio engineer’s handbook, the sounds of slightly dirty overdriven electric guitars were heard from several left-of-center players and genres, and many young British guitarists loved it. You wouldn’t have heard this kind of thing in the charts yet, but plenty of future stars were gobbling up rough-hewn recordings by American blues artists, many of which were textured with that extra bit of hair in the sound courtesy of overdriven Fender, Gibson, Supro, and Danelectro amplifiers, often smaller combos that were easily pushed into distortion.

The British Amp Invasion Softcover Book
By Dave Hunter

One of many seminal stories of an English lad discovering the blues is that told by Dave Davies, former lead guitarist of The Kinks. The British-invasion hit-makers formed in 1961, but even before that, Dave and his brother Ray—who would become the group’s lead singer, chief songwriter, and rhythm guitarist—were aping a tamer, politer music of the day... until the lightning bolt struck. In 1999, Dave Davies told me how he first discovered ‘that sound.’ "Initially, Ray and I used to do duo stuff," Davies said. "He’d write instrumental tunes and I was the rhythm guitar player. We did our first gig when I was eleven in the pub across the road, only because my dad used to frequent the place. We’d do this sort of Chet Atkins thing. Ray had classical training, which really served us well later when we got into the studio, but I just used to pick ... I thought I was Earl Scruggs or something, but I didn’t know what I was doing."

Then came an important event: their brother-in-law introduced them to Big Bill Broonzy. "I’d never heard anything like it. I was awestruck; I just could not believe the power, the soulfulness of it. From then on I knew I wanted to hear more of this stuff— him, and others, like John Lee Hooker. He had a funky guitar sound, and it had that buzz, that drive. I used to listen to him and think what the fuck’s he doing there? That’s amazing—how do you get that sound?"

Davies reckoned it was all those elements that led him to mess around with amplifiers. "Because all the amps were clean, soulless. The blues players were the first to crank it up and the music had that spirit, that anguish, which a lot of working-class people had. You could relate to it easily through music—it was probably the first time working class people had a voice, in the late 50s and early 60s."

At the time, even a little tube clipping into a ratty overdriven speaker was enough to get kids pretty excited, but eventually, that ‘working-class voice’ would get louder and dirtier. Jim Marshall might not have known it yet, but his amps—while designed to offer excellent clean headroom and impressive volume for the day—were primed to dish out the overdrive big time ... and to get kids very excited.

Marshall Moves In

Jim Marshall’s transition from music-store owner to guitar-amp manufacturer is not unlike that of Charlie Watkins and Tom Jennings before him. Come to think of it, it’s not far from the way Leo Fender started, too. Marshall saw a need, and decided to fulfill it himself. The difference, perhaps, is that Marshall came to it at about the top of the current technology; he decided to go big right from the start.

At the time, even a little tube clipping into a ratty overdriven speaker was enough to get kids pretty excited, but eventually, that 'working-class voice' would get louder and dirtier.

Having attained some status as a professional drummer and drum teacher in London, Marshall decided (again, not unlike Watkins and Jennings) to strive for some stability in his life and livelihood by opening a retail shop to expand his sideline of selling drum kits to his students. The first shop, named Jim & Terry Marshall (for his son and business partner), opened its doors at 76 Uxbridge Road in Hanwell, northwest London, in 1960. In 1962, the Marshalls opened a second premises across the street at 90 Uxbridge Road and shortened the name simply to J & T Marshall.

Marshall had been a jazz drummer and would remain a jazz fan throughout his life. Perhaps that makes him an unlikely ambassador between the young rock’n’rollers and the music-industry establishment. He clearly had a way with the young players, though, as well as a keen appreciation of their needs.

"I was certainly the first to cater for rock’n’rollers in the London area," Marshall said in an interview conducted shortly before his death in 2012. "I had so many top drummers as pupils that they started bringing their guitarists into the shop with them— chaps like Ritchie Blackmore, Jimmy Page, and Pete Townshend.

Anyway, all the guitar players would say to me Jim, if you sold guitars and amplifiers, we’d much prefer to buy them from you because all the music shops in the West End treat us like absolute idiots because we play rock’n’roll. Because we don’t play jazz, they just don’t take us seriously. So I did— and they kept their promise!"

Of the amplifiers that Marshall began to carry, the ones that most impressed Jim and many of his customers, including a young Pete Townshend from nearby Acton, were the big Fenders imported from the USA. But these were difficult to get hold of and extremely expensive. The solution, as the oft-told story has it, was to copy the design of the favorite of those American Fenders and render it with easily available British components, building it up in the back room of the J & T Marshall shop in Uxbridge Road.

Jim Marshall and his repairman Ken Bran decided to use the stout Fender 5F6A Bassman combo as their platform, despite the tweed amp being a couple of years behind the evolutionary curve by this time. To do it right, though, they felt they needed a little more engineering help, so they enticed Dudley Craven, an EMI engineering apprentice, to join in the venture. The first effort followed the schematic for the 5F6A Bassman almost to the letter, other than a couple of minor changes to component values, and of course it used British-made transformers, capacitors, resistors, and other components that were readily available off-the-shelf. The prototype that emerged late in 1962 might have looked like a DIY project cobbled together in Marshall’s shed, precisely because it was, but it performed well enough to earn the team dozens of orders for more.

"We started out in my shed," Marshall said, "making an amplifier from Monday to Friday that we could sell in my shop on Saturday. This gave us the money to go out the following week and get more parts. I would have been delighted if we could have built and sold just fifty amps. I didn’t dream that the endeavor would last fifty years."

The early Marshall amps, initially made only as separate heads, copied Fender’s 5F6A Bassman right down to the inclusion of the Fender’s Polarity switch. In the States, before properly grounded (earthed) three-prong AC outlets were common, this feature enabled US players of Fender amps in the 50s and 60s to correct the reverse-polarity current within an amp that might have been plugged in backwards—that is, with the two- prong AC plug reversed in the socket. Properly grounded British mains supplies, which were already designed for grounded three-prong plugs at this time, needed no such switch. Although Marshall and his partners used the same pair of 5881 output tubes carried by the Fender Bassman (a 6L6-equivalent that was difficult to come by in the UK, and relatively expensive), they changed the first preamp tube, which provided the first gain stage for each of the two channels (Normal and High Treble, which had been called Bright on the Fender) from the Bassman’s 12AY7 to a hotter 12AX7. The result would have been a faster onset of distortion in the amp’s preamp stage.

Although the early Marshall amps shared ninety-eight percent of their design DNA with the Fenders that inspired them, there was one component that differentiated them sonically: their speakers. As heavily American influenced as the amp was at this point, the circuit itself really wasn’t producing anything that today would be considered the Marshall sound. The speakers it was driving, on the other hand, and the cab they were mounted in—the classic closed-back Marshall 4x12—played a huge part in the genesis of that sonic archetype.

Although the early Marshall amps shared ninety-eight percent of their design DNA with the Fenders that inspired them, there was one component that differentiated them sonically: their speakers.

As Jim Marshall recalled later: "We started off with 2x12s, but in those days speakers weren’t all that good, so we used two twenty-five-watt speakers and a forty-five- watt amplifier that peaked at around seventy-five watts, and we blew every speaker. That’s when I designed the 4x12. It was purely because we were blowing speakers. I thought about the smallest cabinet I could make to hold four twelve-inch speakers, and there was nothing clever about designing the size, or anything like that. It was purely so that it would go into the transport of those days. We couldn’t make a more powerful 2x12 cabinet because there were not speakers available that could take the abuse of the amplifier. So I made a small cabinet, put in four twelve-inch speakers, and it worked."

In fact, the first Celestion G12 speakers, an early alnico variety, were originally rated at just fifteen watts, so a quartet was most certainly desirable if you intended to play the amp anywhere close to its upper volume capabilities without blowing these drivers. The first G12M ‘Greenback’ ceramic-magnet speakers of around 1965 handled twenty watts, and these were upgraded to twenty-five watts in 1968. Even then, since a fifty-watt amplifier can put out significantly more than its conservative RMS rating at full volume, four speakers would be necessary to ensure safe operation. Eventually, even more speakers would be required to handle the sonic maelstrom, and Marshall would take the template further, again at the behest of local lad Pete Townshend. Meanwhile, in 1963, the Marshall amp head on top of a solid 4x12 cabinet was the mightiest thing on the British stage.

Marshall JTM45

The first production Marshall amps of 1963 now had their control panels conventionally centered, with front panels entirely covered in the ‘salt and pepper’ Vynair fabric that would also be used for early speaker-grille cloth. Later that year, the more familiar ‘sandwich front’ arrived, with front panels bearing a black vinyl strip covering approximately the top third. The redundant Polarity switch was dropped, making room for the logos "JTM45" and "Mk II" on the front panel. By this time Marshall had moved from 5881 output tubes to British-made KT66s, another more robust near-equivalent of the 6L6 that was readily available in the UK. Although it was marketed in Lead, Bass, and PA models, each used essentially the same design. That and the accompanying speaker cab were the only home-grown products the company offered until the arrival late in 1964 of the first combo, the 2x12 Model 1962 Lead & Bass Combo (also known as the Bluesbreaker). That same year, Marshall moved production from Jim’s shed to the back of the Uxbridge road shop. Things looked to be getting serious.

My colleague Rick Batey, a former cohort at The Guitar Magazine (the British magazine today entitled Guitar & Bass), is a long-time owner of a pristine 1963 JTM45, a genuine under-the-bed find. Batey wrote a piece on early JTM45s for the magazine and made some interesting observations about Marshall progress through the early years of its manufacturing business. It’s difficult to imagine, in hindsight, that Marshall’s JTM45 wasn’t instantly adopted as hallowed amplification in the backlines of all the major British stars of the day. But Vox was still the big player in town, Selmer still had a decent foothold, and it took the north-London upstart some time to gain ground with major name players.

Vox was still the big player in town, Selmer still had a decent foothold, and it took the north-London upstart some time to gain ground with major name players.

Marshall’s 1965 catalogue included endorsers Gary Farr & The T- Bones, The Mark Leeman Five, The Second Thoughts, Lulu And The Luvvers, Tony Rivers And The Castaways, Alan Elsdon And The Voodoos, The Next Five, and The Cherokees. Major names? Not one of them. As Batey mused: "It’s hard to imagine a group of names more redolent of clapped-out Ford Thames vans, of Players Weights [cigarettes], of fried breakfasts at 3:00am in transport caffs just off the North Circular. Such were the building blocks of England’s rock’n’roll dream in 1965."

Thanks for Dave and Hal Leonard for sharing this excerpt with us. For more on the evolution of vintage British amps, order the new book here.

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