Among vintage guitar amps, Marshall is of course the 1st or second name you will hear and it’s for good reasons : those amps forged Rock’n’roll and I really cannot imagine music without them. Most guitar heroes have used or still used a Marshall and their music and tones are closely linked to the signature sound of these wonderful amplifiers. So I propose here a trip though the vintage Marshall of my collection, the Blues Breaker having its own page.

JTM45

What would be a better start that the amp that started the whole business ? I will not come with more history about the creation of this legend, but instead will try to give a short description of its tone : beautiful clear at low volume and a really unique smooth with lovely high-end when pushed.

This, of course, if you use original G.E.C. KT66 tubes. Other 6L6 won’t give this amplifier its genuine signature tone. Note both plexi front plates, golden in front and white on the back, folded aluminium chassis and round three prongs AC plug.

JTM100

Shortly after the creation of the JTM45, a strong demand of higher power amps raised in the UK, as the British bands played in bigger venues and needed to be loud. This particular amp may have been created for P.A. but I am sure many guitarists used it.

Very rare amp, which can be considered as the missing link between the JTM45 and the later famous 100w plexi. Spot the very ‘Voxy’ copper vents on top and unusual power transformer.

The Pig

A very rare and mostly interesting amp, as for a long time only mine could be searched on Google. As the audience increased, the guitar players wanted more power – remember in the ’60s , guitar did not come though P.A. – so why not make a 200w amp ?

This clever idea had some drawbacks : MIGHTY and fragile power and output transformers -on my pig, we had to change the power transformer- and the use of KT88…. when it was quite simpler and maybe less expensive to get two 100 watters.

This explains the short life of the wonderful pig , life in which it had the time of recording the legendary tone of Mick Ronson, and the later great number of amps on stage.

1960 cabinet

All these amps needed cabs of course, and the most famous is the 1960A or 1960B. The beautiful original pinestripe grillcloth of the sixties is now a rare sight.

plexi 50w super lead

The succesor to JTM45 differs from its ancestor from few things : a stronger and more convenient stell chassis and the use of the tube that will become standard in all Marshall amps : the EL34 .

You can find great EL34 tubes these days, thanks to the reactivation of once-lost vaccum tubes factoried. But nothing will replace the perfect distortion of the original Mullard when pushed to their far, far limit. This amp is anyway close to perfection unless you need of course its Majesty ….

The Plexi

By ‘plexi’ I mean Marshall Super Lead 100w plexi front, the king of all amps, used by the most famous guitar heroes of all time. You will often hear you don’t know what is electric guitar until you plug into one of these vintage monsters at full volume, and this is really not far from truth.

The power tubes distortion of this amp is perfect : all of a sudden the raw power in your face turns into a nearly mellow distortion so pleasing you won’t stop playing. Tinnitus-friendly for sure. Here again , genuine distortion tone is obtained with vintage Mullard, newer tubes giving a less smooth overdrive, while this could be subtle if you correctly bias your amp and get a perfect quartet of EL34 as it was done here.

Park amps

Park amps were Marshall when Marshall could not use its brand for legal reasons. They had different but becoming cosmetics and supposed to be a tad better. Most Park had the same Marshall equivalent and mine was simply a JMP 100w.

I say was because because this particular amp of my collection went to another famous collection : Joe Banamassa’s. You can actually spot it in numerous video thanks to its flashing blue colour.

Flag logo super P.A.

This 100w P.A. have a rare and short-lived ‘flag’ JTM logo and is a direct sibbling of my JTM100 P.A. on this page. A real beautiful design with its large front face.

It also features the famous cloth-retainers , made of heat resistant coton and giving a real Lewis Caroll look to the amp chassis. Spot the yellow capacitors and laydown transformer, making it a real plexi amp.

Marshall Major

Well the idea of 200w amps did not die completely : they still wanted to use high-power tubes for P.A. as it was the weak point of all big shows at that time. It’s not a plexi anymore and I wonder if this green light is original. But I still like the large front plate…

The cloth retainers were left for sturdy steel to protect the expensive KT88 or 6550 while it may not have been a good idea to mix them like here. I suppose the strange small double circuit board on the left is a test point for bias or a bug killer.

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Silicium might be an endangered species. Progress around carbon electronics (nanotube and tripods) and nanotech are going so fast that a well-known Japanese TV brand is issuing next year a flat TV screen using carbon nanotube. Much more than this, in our days of digital technology, it is quite uneasy to find the simplest Silicium transistors essential for fuzz box craft.
In this context, it may seem ridiculous to focus on the old germanium electronic science, which main actors are just fond memories of the past.
Nevertheless, and I am not the only one to think this way, nothing sounds half as good as a well-tuned germanium distortion device for electric guitar.

This is why today, I would like to introduce you to my old buddy, the AC128 germanium transistor ,
exclusively used in my handmade Mercer Box and KATAPULT pedals .

Besides being in the famous original Fuzz Face, the AC128 was used in numerous domestic electronic appliance, and certainly one of the most common European transistor. This explains why it is still possible to find nice new-old-stock of these jewels.

They usually come in 3 different types :

The real thing

This is both the oldest and arguably the best sounding AC128. It is very similar if identical to the infamous NKT275 which equipped the original Jimi Hendrix grey fuzz face .
But this wonderful piece of crap has a major drawback : completely random technical data in a VERY wide range. This means that any given theorical design has something like 30% odds to function right away. This fact has 2 consequences:

1- Each distortion device using this same transistor must be modified afterwards to match the theoretical technical data of the set of 2 or more transistors.

2- This a posteriori adaptation must be made while monitoring the tone of the resulting distortion in order not to drift away from the prototype.

Nowadays cheap transistor tester are avaible widelyso transistor selection is a tad easier.

It is therefore easy to understand that this kind of transistor is not industry compatible. Only handmade and hand-tuned devices can benefit from this nasty gremlin. Beauty has its price.

The hottie

This strange device is exactly the same transistor BUT with a factory mounted radiator, useful in other applications where it receives its 32v possible supply. The AC128 can be as hot as a soldering iron in certain cases with no damage. Compare this to a ts9 chip.

You will find these square beatuies often in a matched pair with a AC127. Those pairs were used in the not-so-distant past for making small amps that will go in radio, record players etc … remember the Queen deacy amp was powered by ac128 as power transistors.

I feel the radiator somehow tightens the fuzz tone, while not in a big way, making it a valuable successor.

The modern

Well, they were the last poduction AC128 and can be found easier in new old stock. Their data is even more erratic , with hfe gain going from floor to roof in the same batch. I don’t recommend them for beginners.

Unfortunately,while really good in booster / one-transistor pedals, this young component gives a higher even/odd harmonics ratio in fuzz pedals than its pain-in-the-ass ancestor. So the resulting distortion is , exaggerating, closer to a metal zone than a fuzz face.

They are precious anyway, as they fit in the original fuzz face design without any change and give a very acceptable approximation, even for a purist. They really are pure germanium after all!

The little sister

The AC188 pictured here, is a scaled down version of the modern AC128, made for lower voltage applications. And what are our 9v fuzz box ? In fact , this little sister does miracles with electric guitars.

Pushed to their limits, they deliver a full frequency grawl that is hard to beat. A very interesting transistor indeed, the AC188 is too rare to give its full dimension but remains one of my fave if you know how to use it.

the OC family

OC prefixed transistors were made by Mullard and Valvo , and are famous among pedals aficionados because they were present in famous classics such as Marshall supafuzz and eraly vox tonebenders. They usually are good quality and good sounding. The oc75 seems to have been manufacured or selected for good and constant Hfe , making it a perfect choice , while the oc76 must be sorted but yet is also a great choice for fuzz pedals. I can imagine OC75 were selected OC76 , just like Philips were offering different selection for their great dac chip tda1541 .

The Frenchies

The first transistor to be produced in France was invented by Doctors Welker and Mataré of the Société des Freins et Signaux Westinghouse (F & S Westinghouse) in mid 1948 and announced to the World in May, 1949

In the world of fuzz, some french transistors made their way to history such as the SFT352 present in the famous Elka Dizzy Tone which was at my time a modest copy of the tonebender.

But in 1962 , the two companies present in the early days,
Thomson-Brandt and CSF merged into two new firms , COSEM in the French Alpes and SESCO in Aix-en-Provence , a few miles away from my hometown, Marseille.

So it’s no surprised I found here nice supply of germanium transistors from SESCO, including my fave, the 324TI which has perfect HFe and noise level for fuzz pedals.

These means I can do a nearly 100% made in Marseille pedal, which I call the F.F.F. ( French Fuzz Face ) . Please send me a note if you’re interested.

EPILOGUE : When supply will dry…

In a very close future, all stocks, including mine, of original germanium AC128 or any usable germanium transistor will dry.

Forever.

After this extinction, that only a few aficionados will notice, there will be no other possiblities to obtain THE original fuzz tone than a used Germanium fuzz box or a digital model.

Make your choice.

From my point of view, I feel my ’65 strat deserves more than a plastic computer. And in my experience, no digital guitar tone can sound good live or even recorded.

” How well you know me

You’ve seen me cry

I’m just a shadow

In a rock’n’roll sky “

Deep Purple 1973 “Super Trooper”

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