The History of the Legendary Marshall 100-watt “Plexi” Head

Amps: The Unsung Heroes of Rock

Guitars invariably get all the glory in rock, but, in
reality, they’re only half of the all-important sonic story. I mean, what’s
your most beloved axe sound like without an amp? The answer is simply this:
it’s effectively silent. It’s merely a block of wood with some strings on it.
It might be a priceless, stunning-looking 1959 Gibson Les Paul that plays like
a dream, but, without an amp, the
electric guitar loses its purpose ­— it loses its all-important voice. Like it
or not, a banjo or even a ukulele will drown it out!

Yep, in order for an electric guitar to be truly heard, it needs its partner in crime — the amp.
Furthermore, the amp you plug into can literally make or break the resulting
tone of even your most beloved guitar. As has been proven countless times, an
amazing custom-shop axe paired with an awful amp can be tonally crushed by a
much lesser guitar plugged into an amazing amp. Case closed.

Because of this simple, irrefutable truth, we’re going to start singing the praises of these unsung heroes of rock, pop, country, metal, and all things electric guitar. Many moons ago, a dear friend of mine, Ritchie Fliegler, wrote a wonderful book on this very subject, and its title says it all: Amps! The Other Half of Rock ‘n’ Roll.

Some of the reference books used to ensure the accuracy of this article — including Mr. Fliegler’s awesome, aforementioned tome.

We’re gonna get this ball rolling with a truly iconic
electric-guitar amplifier: the game-changing Marshall 100-watt “Plexi” head.

The History of the Marshall 100-watt
“Plexi” Head: 1965–1969

There’s an amazing array of great rock guitar amps available
right now, and they come in a mind-boggling variety of shapes, sizes, and sorts
— from high-tech digital profilers, modelers, and plug-ins to good ol’ fashioned
analog solid-state and tube-driven offerings... plus all points in between.
In fact, one could successfully argue that there’s never been a better (or more
confusing) time to buy an electric-guitar amp!

This said, despite the vast number of wonderful guitar-amplifying options out there, only a handful have truly earned the esteemed title of “legendary.” Furthermore, when it comes to all things classic rock, hard rock, early metal, and even punk ­— one amp in particular quite literally stands head and shoulders (sorry, bad pun not intentional) above the rest: the fabled 100-watt Marshall “Plexi.” This British-born, handwired*, all-tube beast is about as simple as they come: no gain control; no effects loop; no channel switching; no reverb; no DI output; no nothing. All it offers is this: an incredible, intoxicating, touch-responsive primal roar — provided it’s cranked up to a deafening “eleven,” of course! The rest is totally up to you, the player.

*All Marshalls made from the company’s birth in 1962 until 1973 were handwired. The transition to PCBs (printed circuit boards) happened during ’73.

The glorious, handwired guts of an old 100-watt “Plexi” Super Lead head.

Judge This Amp by the Company It Keeps

Why are these old 100-watt Marshall heads regarded with such reverence? A quick look at some of its highly influential users will reveal all: Jimi Hendrix; Cream-era Eric Clapton; Duane Allman; Jimmy Page; Jeff Beck; Edward Van Halen (David Lee Roth–era Van Halen); Johnny Ramone; Billy F. Gibbons; Wayne Kramer; Paul Kossoff; Malcolm & Angus Young; Eric Johnson; Yngwie Malmsteen. I could go on (and on and on!), but I think you get the picture! Yes sir, the 100-watt Marshall “Plexi” has been the amp of choice for countless guitar heroes for over 50 years. It’s not surprising that many (myself included) consider the 100-watt “Plexi” to be one of the sonic cornerstones of rock as we know and love it today.

“Plexi” & Super Lead: What’s in a
Name... or Two?

The answer is, of course, everything. That said, thanks to a
lot of amp-modeling devices using the term “Plexi” so liberally, a great many
folk understandably think that the name automatically means a 100-watt Marshall
head. I hate to break the news, but that’s not
always true. The two might appear synonymous, but that’s not always the case. Why? Because not all Marshall
“Plexi” heads are 100 watters, that’s why!

Then, to add further to the melee, while there are 100-watt
“Plexi” heads that bear the name “Super Lead,” not all 100-watt “Plexis” are
Super Leads. And, furthermore, not all 100-watt Super Leads are “Plexis!”

Confused? If so, fret not. Read on, and all will be revealed. First though, let’s quickly touch on where the “Plexi” name came from.

The name “Plexi” stems from the fact that the front and back panels of the amps in question are made from an acrylic* material many refer to as plexiglass ­— and “Plexi” is obviously merely an abbreviation of that name. To be precise though, Plexiglas is actually the name of an acrylic manufacturer that’s become so synonymous with the material that the brand’s name has become a generic term for the stuff ­— regardless of who makes it. Kind of like how “Kleenex” is synonymous with “facial tissue.” After all, when someone says, “Pass me a Kleenex,” they’re not asking for a Kleenex product, just a tissue of some sort!

*Acrylic is a transparent plastic material that’s extremely strong, rigid, and clear.

TRIVIA!As the acrylic material Marshall used for the front and back panels of these legendary amps wasn’t actually made by the Plexiglas company, certain folk have humorously nicknamed it “Perplexi” as many people also refer to said acrylic material as “perspex,” too ­— geddit? And, as added irony, Perspex also happens to be the name of a brand that makes acrylic sheet!

That explained, let’s clarify what is what in the sometimes perplexing (sorry, couldn’t resist!) world of Marshall “Plexi” heads.

Plexiglass by name, plexi-“glass” by nature! As you can see from this road-worn, ol’ trooper, a “Plexi” panel can and will crack or break if hit hard enough. The amp, however, didn’t despite the brutality of the hit it took — this one still sounded and felt great to play.

Not All “Plexi” Heads Are 100 Watters!

The very first Marshall head, the equally famous JTM45, had a panel made from the same exact material and, as a result, is often referred to as a “Plexi” by some. This classic, small-box* head delivers a mean 30 watts (not 45 watts, as often stated**) and is still available today as a reissue. As you’re about to discover, the JTM45’s preamp (and front panel!) played a vital role in the creation and evolution of its bigger, 100-watt brother.

*The term “small-box” is often used to describe the wooden cabinet the JTM45 lives in as it’s ­— wait for it ­— smaller than the 100-watt amp box. While the height and depth of both boxes are pretty close, the 100-watt box is three inches wider.**The understandable reason a great many folk assume that the JTM45 is a 45-watt amp is obviously because of the “45” in its name! Here’s the myth-busting truth behind the name: JTM is an acronym for Jim & Terry Marshall — Terry being Jim’s son. As for the 45 — it refers to the fact that the amp will put out 45 watts when cranked to the max, namely, at full distortion. However, that’s not how guitar-amp companies like Marshall typically measure power. Instead, they measure the amp’s clean power — namely, with no distortion. FYI, this measurement is sometimes referred to as RMS. To this end, the JTM45 puts out 30 watts of clean power; 45 is merely its peak. So, now you can see why many old Marshall tube amps are so darned loud and can blow up speakers — their power rating is pretty darned conservative!

Talking of the 100 watter, it also happens to have another small-box sibling with a plexiglass panel ­— the 50-watt model 1987 head, another Marshall head commonly called “Plexi.” This one is also still available as the 1987X reissue.

The current Marshall 1987X reissue — it has a plexiglass front panel, but it’s a 50-watt amp housed in a slightly smaller head box.

Because of this pair, a “JTM45,” “50-watt,” or “100-watt”
qualifier will avoid any possible “Which Plexi are you referring to?”
confusion. Make sense? That’s why the title of this piece is “The History of
the 100-watt Marshall ‘Plexi'” and not merely “The History of the Marshall ‘Plexi.'”

And, talking about confusion, let’s sort out a couple of
other confusion-inducing aspects regarding the subject of this article...

Not All 100-watt “Plexi” Heads Are
Super Leads... & Vice Versa

As mentioned earlier, the name “Super Lead Plexi” is
frequently used when talking about our 100-watt subject. The trouble is, not
all 100-watt Marshall heads with plexiglass panels made between 1965 and 1969
were Super Leads. This is because said label wasn’t added to the amp’s rear
panel until early 1967.

Furthermore, as the Super Lead name continued to be used
after the amp’s front-panel material was changed to aluminum in mid-1969, not
all 100-watt Super Leads are “Plexis” either!

One more minor point of name-induced confusion to clarify, and then we can move on.

The handwired insides of an old Marshall JTM45/100 “Super 100” head — this ancient beauty is 100 watts and does have a “Plexi” front panel... BUT it’s not a Super Lead!

IMPORTANT!ALL original, vintage Marshall 100-watt “Plexi” heads were handwired... no exceptions!! This, however, is not true of all reissues. Read on...

Marshall Handwiring

The art of handwiring amps — an ancient but not forgotten Marshall art!

THEN

NOW

1959: The Model Number, Not the
Year!!

In 1966, Marshall signed a 15-year distribution deal with Rose-Morris, and said company gave the 100-watt “Plexi” head the model number 1959. Due to the fact that 1959 is such an iconic year when used in conjunction with the Gibson Les Paul, this unfortunate model number is a common cause of confusion. Rest assured, when someone says “1959 Plexi,” they’re referring to the amp’s model number, not the year it was made! Especially as Marshall didn’t start making amps until 1962!*

*1962 also happens to be the model of another much-lauded Marshall, the Bluesbreaker combo Eric Clapton made famous. Once again, nothing to do with the year ­— another one of Rose-Morris’s confusing faux pas!

As the 1959 model number remained in use after the amp’s
front panel was changed to brushed aluminum in mid-1969, not all 1959s are
“Plexis.” And, just like the Super Lead name, because the 1959 model number
wasn’t designated right away, not all 100-watt “Plexis” are 1959s either!

1959 TRIVIA!The model number/name 1959SLP is frequently used, too, nowadays. SLP is an acronym for “Super Lead Plexi,” which is nice and specific. To be historically accurate, the 1959SLP model number wasn’t used until the amp was reissued in 1993.

MKII TRIVIA!You’ll see “MKII” on many of the plexiglass front panels in this article. MKII was used for quite some time on all Marshall “Plexi” panels after the JTM45 prototype and initial production run in late-1965. It wasn’t model specific though — thus, as a result, you’ll see it on old JTM45s, 1987, and 100-watt “Plexi” models. And on the current JTM45, 1987X, and 1959HW reissues, too.

Phew, hopefully that has unmuddied the waters.

In summary — all original Marshall
100-watt “Plexis” have four things in common:

They’re 100 watts... duh!!
The “big box” and a quartet of power tubes are the dead giveaways here!They have a plexiglass front
panel... duh #2!!They’re handwired.They were actually made
by Marshall!! I saw a couple of simply stunning fakes during my tenure with Jim...

This all said, now it’s time
for a quick trip down memory lane.

Back to the Beginning

As hard as it might be to imagine, there was a time not so
very long ago when a lot of the things we take for granted today just didn’t
exist. There were no cell phones; no internet; no Facebook; no YouTube; no
laptops; no texting or tweeting... in fact, homes didn’t even have
microwaves! And that’s where this story starts: in London, England, during 1965
­— a time when rock was in its infancy; TVs weren’t even color let alone
big-screen; and the only way to listen to music, other than at a live concert,
was on the radio or by plonking a vinyl record on a clunky turntable. Yep, it
was pretty darned primitive by today’s standard. Anyway...

An entrepreneurial chap named Jim Marshall was already making a name for himself by building tube guitar amps that delivered the aggressive sound the young, emerging rock bands desired. One of the most promising Marshall-abusing acts around England at that time was The Who.

One of my all-time favorite snaps of “the Guv’nor.” Taken in 2003, it captures an 80-years-young Jim with the then 41-year-old amp that started it all: the legendary prototype JTM45 known as “Amp Number One.”

“Make Me a Sonic Weapon”

The Who’s guitarist, Pete Townshend, loved the sound of his
Marshall amps, but he had a problem ­— he didn’t think they were loud enough
for the larger venues the band were playing. Plus, to make matters worse, the
guitarist could see people in the audience talking while he was playing, and that
infuriated him. How dare they?! So, Pete met with his friend Jim Marshall and
begged him to build “a sonic weapon” that was so loud that no one in the crowd
could even dream of talking while he was playing! As Mr. Townshend recalled in
the September 2002 issue of Guitar World
magazine: “I went to Jim Marshall, stomped down my 50-watt amp, and said: ‘I
want that, twice as loud’... Jim’s eyes lit up and he said, ‘I will supply
this man with the weapon he requires!'”

Trivia!Pete also insisted that these new sonic “weapons” come with 8×12 cabinets, a request that ultimately led to the invention of the Marshall stack. That’s another story... stay tuned to this inSync channel for that one as it’ll be coming soon.

As Pete’s Guitar World
interview revealed, Jim and his team happily accepted this bold mission: to
make a 100-watt guitar amp that was so loud that no one in the audience would
be able to talk while Townshend was performing.

For the sake of historical clarity at this point of the proceedings, I should point out that Marshall wasn’t the first company to enter the 100-watt guitar-amp arena. Another well-known English amp maker, Vox introduced the 100-watt AC100 in 1964 for some band called the Beatles. In fact, due to The Who’s desire for more stage volume, the band switched to the new Vox AC100 amp for a while, but it didn’t work out as they’d hoped. To quote Pete from the same interview: “We figured it would be louder, but it wasn’t. It just blew up.” That explained, back to Jim Marshall’s quest.

A reissue 100-watt “Plexi” that sits in the Marshall museum, signed by the legendary Jeff Beck. When asked to submit a handwritten quote to celebrate Marshall’s 40th anniversary in 2002, Mr. Beck simply penned this: “It’s all your fault!” Amen to that...

Early Development

Jim and his trusty team of designers, Ken Bran and Dudley
Craven, built the first prototype in mid-1965 using a quartet of 6L6 tubes and
the preamp of a JTM45. They were faced with a major hurdle though ­— the output
transformer. Unfortunately, the largest one available at that time simply
couldn’t handle the task of producing 100 watts of output. As a result of this
shortcoming, the first prototype only kicked out about 60 watts. Undeterred,
Jim’s team soldiered on, and their second prototype employed two output
transformers to handle the power the four 6L6s delivered when the amp was
cranked “to eleven.” The results were both encouraging and, wait for it, much
louder... duh! The guys were clearly onto something.

Next came prototype #3. As well as having two output transformers, this bad boy boasted four KT66 tubes; and, reportedly, the head’s output not only hit 100 watts — it exceeded it. Mission accomplished!

The “back-panel-off” view of a Super 100JH reissue (read on) — it doesn’t sport a pair of output transformers, but it does house a quartet of bulbous KT66 power tubes.

The JTM45/100 Dual-Output-Transformer
Head

As a result of prototype #3’s success, Marshall produced
their first 100-watt head in late 1965. The quad of KT66 power tubes remained,
but the output transformers were changed from Radiospares ones to a pair of
50-watt Drakes. The resulting head was affectionately nicknamed “the JTM45/100”
as it used the JTM45’s preamp. It also used the JTM’s plexiglass front panel.
These “dual-transformer heads” are super rare as, in September 1965, Drake
introduced a 100-watt output transformer. Not surprisingly, Marshall quickly converted
to using this new offering, and so the single-output-transformer 100-watt head
was born.

TRIVIA!In 2005, Marshall celebrated the 40th anniversary of the birth of the 100-watt stack by offering a limited-edition reissue of the rare “JTM45/100” dual-transformer beast ­— handwired and loaded with a quartet of KT66s, of course. And, to add to its authenticity, Drake duplicated the 50-watt output transformers for the occasion. Said reissue sported a black, block Marshall logo as opposed to the famous script one because that’s how Pete Townshend’s first 100-watt stacks were badged. Trivia tangent over; back to the plot.

The meticulously handwired interior of Marshall’s (extremely) limited edition reissue of the fabled Dual-Transformer JTM45/100 head in 2005. Truly a thing of beauty...

Ch, Ch, Ch, Changes...

Over the next couple of years, the JTM45/100 continued to slowly but surely evolve in terms of tone. The gold JTM45 plexi front panel and the white rear panel proclaiming “Super 100 Amplifier” remained the same; but, sonically, impactful things such as power transformers, higher voltages, and chokes were changed. Also, as the late, great Jim Marshall told me on more than one occasion, sometimes changes would be caused simply by component availability. A lot of artists who remain highly influential to this day embraced these amps with arms wide open ­— including Jimi Hendrix* and Eric Clapton. Pictorial evidence reveals that both the Jimi Hendrix Experience and Cream used early JTM45/100s a great deal in 1966–67. Jim not only supplied these guys with amps, but he also continued to listen to their needs.

*In addition to the Marshall tone he heard when he first went to England, Jimi wanted to meet Jim because his full name was James Marshall Hendrix. The two met and became friends, and the rest is rock history. In fact, Jim often referred to Jimi as “my greatest ambassador without any doubt at all...”

The guts of a really, really old JTM45/100 allegedly used by Jimi Hendrix at the Monterey Pop Festival in California, USA, in the summer of 1967.

The Customer Is Always Right

As a result of Jim’s close relationship with artists,
modifications were also made when someone like Jimi Hendrix asked if the amp
could be a little more “toppy” or “aggressive.” Jim’s credo in such
circumstances was: “Listen carefully, make sure you understand, and then strive
to not only meet expectations but beat them.” What a concept!!

Enter EL34 Power Tubes

In February 1967, a new Drake output transformer and a quartet of EL34 power tubes were introduced. Not surprisingly, these two changes had a significant tonal impact, making the amp dirtier and more aggressive sounding. The amp was also noticeably louder, too ­— good yet painful!

A vintage “Plexi” Super 100 amplifier that’s been freshly retubed with a brand-spanking-new quartet of EL34 power tubes.

The Super Lead and Super Bass Models Are
Born

In the late spring of 1967, gold, acrylic back plates proclaiming “Super Lead” and “Super Bass” were introduced. The JTM45 front panels remained, and a 500 pF bright cap was put into the Super Lead’s preamp, making its tone brighter and more aggressive. The Super Bass (model 1992) used the same exact circuit ­— sans the bright cap, of course. The reason I mention the Super Bass version is because, in addition to being synonymous with legendary bassists such as Lemmy* of Motorhead and Jack Bruce of Cream, a number of significant guitarists have one in their arsenal ­— including John Frusciante of the Red Hot Chili Peppers, Adam Jones** of Tool, and the much-respected Texas blues player Lance Lopez. In fact, Lance was gracious enough to supply us with the below photos of his.

**The late, great Lemmy’s infamous “Murder One” Marshall Super Bass head was a 1992 made in 1976 (see what I mean about confusing model numbers!), so it sported a brushed-aluminum front panel, not a plexiglass one. It was painstakingly replicated by Marshall in 2008 and released as the Limited Edition Lemmy Kilmister Signature 1992LEM.**Due to my OCD, I should point out that Adam Jones’s Super Bass was: A) a late-’70s model, so an aluminum-panel model, and B) it has been reliably reported that it has been modified back to 1959 (Super Lead) specs.

A pair of much-missed legends and dear friends — Jim & Lemmy. Sure, both Lemmy’s original “Murder One” and his limited edition signature 100-watt Super Bass heads had aluminum front panels and weren’t handwired, but I don’t care! How could I not include this great photo?!

This is another “off-script” photo I simply had to include. This shows the handwired insides of Lance Lopez’s early-’70s Super Bass head. Sure, it sports an aluminum front panel, but it’s yet another wonderful example of Marshall’s glorious handwired era of yesteryear. Another reason for including this one? It’s rumored to have belonged to Roger Glover of Deep Purple. I rest my case — thanks Lance!!

More Trivia: Black Flag Time

In mid-1967, the amp’s chassis was changed from aluminum to steel, making them sturdier and also cheaper to make. The amp’s front panel also featured a reverse JTM* logo to the left of the Power and Standby toggle switches. In case you’re wondering what a “reverse JTM logo” looks like, check out the picture below, and all will be revealed. These heads are often referred to as “Black Flag” amps as a result and are now worth a small fortune as they were only made for a short amount of time. They’re also sometimes called “JTM100s,” as opposed to “JTM45/100s,” due to this panel change. Pictorial evidence indicates that users of said Black Flag amps included Paul Kossoff (Free), Jimi Hendrix, and, more recently, Eric Johnson.

A close-up of the “Black Flag” logo on an incredibly rare (and expensive!) 100-watt JTM45/100 “Plexi.” Photo courtesy of my new, “over-the-pond” pal Justin at London Vintage Guitars.

From JTM to JMP

Later the same year, the “Black Flag” logo was replaced by
three bold, black capital letters: JMP ­— an acronym for Jim Marshall Products.
These models are known as the first “JMP100s.”

Super Lead Preamp Evolution

In 1968, Marshall made a pretty significant change in the
amp’s topology by adopting what is known as a split-cathode preamp circuit.
This also changed the tone of both the amp’s channel options ­— Normal and
Bright. The result? A louder, tighter, and more aggressive-sounding beast.
Later in 1968, the preamp filter values were raised, giving the amp tighter
bass and a somewhat “stiffer” feel. The most famous 1968-made Super Lead?
Undoubtedly, it’s the one owned by the late, great Edward Van Halen, which he
used on those first few groundbreaking albums, noticeably the band’s
game-changing self-titled debut unleashed in 1978.

TRIVIA!Contrary to common belief, Eddie’s fabled “Plexi” wasn’t modded. The reason that he was able to coax those incredible tones from the amp was due to three things: his incredible hands and ears plus a Variac that he used to lower the voltage to achieve the sound he wanted to hear. Dropping the voltage will cause both the preamp and power-amp sections to distort earlier, plus it will change tonal characteristics and the damping, too, making the amp a little more “spongy.”

In 1969, a resistor value was changed in the Brilliant channel, giving it a crisper tone that cleans up nicely. According to the much-respected Marshall expert/historian Mike Doyle, this version of the amp was used by Jimmy Page, Jimi Hendrix, and also Eric Johnson.

The End of the Golden “Plexi” Era

In the middle of 1969, Marshall made the decision to replace the acrylic panels on what was already a legendary amp with aluminum ones. The amp’s guts remained the same ­— for a while ­— but it was obviously no longer affectionately known as “the Plexi.” Further modifications took place in the early ’70s that made the 1959 even rawer and dirtier, and the aluminum-paneled versions continued to literally drive hard rock forward via countless bands including Judas Priest, Thin Lizzy, and AC/DC. Yep, the “Plexi” era was no more, but the Super Lead marched boldly on, even when its handwired insides were replaced by PCBs in 1973.

Yet another “had to use” photo — the 1959RR Limited Edition Randy Rhoads Tribute head. A wonderful example of a 100-watt Super Lead that’s not a “Plexi” due to its aluminum front panel. The signature you can see? Delores Rhoads — Randy’s beloved mother who blessed the project... RIP dear lady.

100-watt “Plexi” Reissues: Then &
Now

Reissue #1: The 1959SLP

Due to an ever-growing interest in amps of yesteryear, Marshall decided to offer a reissue of the 1959 “Plexi” in 1993, following a disappointing public reaction to a reissue of a circa-1973 Super Lead with an aluminum panel in 1988. The 1993 reissue was named the 1959SLP and was based on a late-1968/early-1969 model. Unlike the original though, the reissue wasn’t handwired; it boasted PCBs. It was well received though and stayed in the line for the best part of a decade until it failed to pass new safety regulations issued in the late 1990s. Thus, a major rethink was required.

TRIVIA! – the “Barney Plexi” 100-watt StackIn 1994, Marshall released a (very) limited run of purple “Plexi” full stacks ­— 100 for the USA and 100 for the rest of the world. This eye-catching rarity was named the “Limited Edition Marshall Hendrix full stack” and featured a model 1982B LTD straight-fronted cabinet, which is taller than a regular Marshall 1960B 4×12. Not surprisingly, this behemoth sold out almost instantly. Due to this stack being unusually tall due to the oversize straight cab, it was nicknamed “Barney” after the purple dinosaur in the once-popular kids’ TV show of the same name.

Reissue #2: The 1959SLPX

By the early 2000s, Marshall had a new R&D team, and
they were totally committed to making this reissue all it could be. They knew
that, to do so, they had several hurdles to clear in addition to the new global
safety requirements. In a nutshell, those hurdles were:

They were well aware that the initial design was changed pretty frequently that such seemingly small changes could well have a major sonic impact. The fact that said changes were rarely documented merely compounded this problem. Thankfully, some excellent archiving work by Mr. Phil Wells helped considerably.The tolerances of the components used in the 1960s left an awful lot to be desired. Consequently, two amps made back-to-back could well sound different than each other. So, which “Plexi” Super Lead from 1967–69 represented the true sound of the “classic”?!

In order to choose an original Super Lead “Plexi” truly worthy of the label “classic,” the team used both history and the opinions of players and experts from all over the world. They also did exhaustive component measuring to ensure the utmost accuracy. A year later, the 1959SLPX was launched and received glowing accolades from players and the press alike. Once again, though, PCBs were used. The reason for the “X” at the end of the name? Because, due to public demand, a series effects loop was added ­— with a True Bypass switch to satisfy the purists!

A zoom-in on the rear panel of the 1959X to show that all-important “BYPASS” switch for its effects loop. To some, its inclusion remains heresy, though, despite said switch!

Reissue #3: The 1959HW Handwired Super Lead “Plexi”
Reissue

Despite the rave reviews the 1959X received, there was an inevitable slew of “Please make a handwired one, too” ­— especially when Marshall unveiled handwired versions of two all-tube 1960s gems, the 18-watt 1974 combo and the 20-watt 2061 head, in mid-2004. Said wish was granted in 2005 when the 1959HW was unleashed. This handwired beauty is still available today and is based on two different original Super Lead “Plexis” that the Marshall team felt “exemplified the Plexi sound.” The fact that one of said heads was only 60 serial numbers away from the heads Jimi Hendrix used at his legendary Woodstock Festival performance in 1969 added even more excitement and vibe.

A Modern-Day 100-watt “Plexi” Rarity

In order to make this piece as complete as I can possibly
make it, it would be extremely remiss of me not to include this.

Jimi Hendrix Tribute Super 100JH Head

2006 marked the 40th anniversary of the first meeting of Jim Marshall and Jimi Hendrix ­— two guys who both shared the name James Marshall (remember?). To celebrate 40 years of this historic relationship, Jim decided to produce a limited-edition handwired stack in honor of his friend. To ensure this Super 100 head was as accurate as possible, Marshall contacted techs and roadies of the period to ascertain that Jimi’s first heads were completely stock except for the tonal enhancements the guitarist requested Jim make (slightly more treble and bass). Only 600 of the resulting handwired beauties boasting KT66 power tubes and Drake transformers were made. Offered as a full stack only and launched with Jimi’s sister Janie, they quickly sold out.

The rare and wonderful Marshall tribute to Jimi Hendrix — the Super 100JH head. Note both the “MKII” and “JTM45” on this 100-watt reissue’s historically correct front panel.

Conclusion

Hopefully this lengthy piece has proven both entertaining
and informative. I certainly enjoyed penning it, that’s for sure. I also
sincerely hope that it helped clarify some of the murkiness in the often
turbulent “Plexi” pool.

In my humble opinion, the birth and evolution of this legendary head between the years of 1965 and 1969 is living, fire-breathing proof of Jim Marshall’s ability to listen carefully to what the up-and-coming guitarists at the time wanted, understand it, and then deliver the goods. And boy, did he and the 100-watt “Plexi” deliver! I honestly can’t imagine what rock would sound like or where it would be without them. Rest in peace, Jim, my friend... and thank you for creating “the sound of rock.”*

*Marshall used this slogan for many years but “the sound of rock” wasn’t created by some high-flying, high-priced, “New York, London, Paris” advertising agency, it was coined by Marshall users. Let it be written, let it be said – or perhaps that should be, er, said the other way around?!

The author with his friend and mentor, the late, great Jim Marshall.

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