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Pigs and Majors

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  • #1

    Pigs and Majors

    Hello Folks.
    Have a little interest to know the truth story about those Marshall monsters. All infos found on internet shows the original "the Pig" was a GEC design cause Marshall cannot developed a proven 200w monster. I have some doubts about. By circuits Marshall 200 and PA 200 seems very awkward designed not an engineered mind showing a weak tentative to make a 200w PA amp. On the other hand the next Marshall generation, means Majors (1966,1967,1978 models) looks more like a copy/paste from GEC manual, What is the truth of this story of this "babies" ? What was the Marshall intention ? They put a lot of effort to develop this product and they stopped few years later. Why ?
    "If it measures good and sounds bad, it is bad. If it measures bad and sounds good, you are measuring the wrong things."
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  • #2
    According to Wikipedia, they "ceased production when the supply of KT88's ran out".

    https://en.wikipedia.org/wiki/Marshall_Major

    I'll also speculate (and it is purely speculation), that P.A. systems were becoming larger and the need for a 200W amp was becoming less. These amps probably weren't a hot ticket any more. Most companies make these kinds of decisions based on the market.
    Last edited by The Dude; 07-07-2017, 01:16 AM.
    "I took a photo of my ohm meter... It didn't help." Enzo 8/20/22

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    • #3
      Okay, I don't know if you have seen this yet, but I think it's on tubebooks.org, there's a GEC design book, going from 5W designs all the way up to I think 1,000. And lots of KT-88 and UL designs. It might offer some insight to the Marshall. Marshall may have tried to simplify a GEC design - factory, keeping costs low, business, etc. That book midght be worth looking for...

      I think the Major probably came about because of a bunch of whiny sissies complaining that their Marshall200 was "too loud - I can't get any distortion cuz me wussy little eardrums hurt..." And that's when the Marshall 200 got a Master Volume!

      In all seriousness, the Michael Doyle book did say that the original "Pig" used "active" controls. Whether or not that's technically true, I don't know, but the simple setup and the general circuit did not really line up with what Marshall users and fans were used to, so they brought the 200 more in line with the rest of the Marshall line, at least preamp-wise... it was kinda like when I got my first 60s Ampeg after playing Fenders for years - it's not that it was "bad," but I just wasn't willing to take the time to learn to exploit the different design when any old Fender takes me right to where I want to go.

      Same Doyle book made sure to mention that Mick Ronson preferred a Pig...

      Justin
      "Wow it's red! That doesn't look like the standard Marshall red. It's more like hooker lipstick/clown nose/poodle pecker red." - Chuck H. -
      "Of course that means playing **LOUD** , best but useless solution to modern sissy snowflake players." - J.M. Fahey -
      "All I ever managed to do with that amp was... kill small rodents within a 50 yard radius of my practice building." - Tone Meister -

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      • #4
        those book I considered too. Nice one. But look at first 200w design meant "the Pig". 12ax7 long tail to drive 4xkt88. It cannot be proper drived and raise the voltage into plates to 750V doing a lot of shit (It was a sort of bomb blowing everything). And those useless tone control... This was a GEC approach too ?
        Last edited by catalin gramada; 07-07-2017, 01:33 AM.
        "If it measures good and sounds bad, it is bad. If it measures bad and sounds good, you are measuring the wrong things."

        Comment

        • #5
          I don't know - I'm just thinking to compare that actual GEC 200W design to the Pig. That GEC book will settle whether the Pig was a GEC design or not. It would simply verify or not whether Marshall was trying to copy a GEC or if they just really blew it with the Pig.

          Justin
          "Wow it's red! That doesn't look like the standard Marshall red. It's more like hooker lipstick/clown nose/poodle pecker red." - Chuck H. -
          "Of course that means playing **LOUD** , best but useless solution to modern sissy snowflake players." - J.M. Fahey -
          "All I ever managed to do with that amp was... kill small rodents within a 50 yard radius of my practice building." - Tone Meister -

          Comment

          • #6
            Originally posted by Justin Thomas View Post
            I don't know - I'm just thinking to compare that actual GEC 200W design to the Pig. That GEC book will settle whether the Pig was a GEC design or not. It would simply verify or not whether Marshall was trying to copy a GEC or if they just really blew it with the Pig.

            Justin
            Was just looking at the GEC book in the 200 watt amps one of the 2 tubes in the output was a DA100 used 2 el84 to drive 2 kt66s to drive 2 DA100s That was the class AB for reduced output of 200watts. Check out data on this tube. NT36 @ The Valve Museum
            nosaj

            Looking at the schem here http://music-electronics-forum.com/t8345/#post373977 I don't visually see any relavence to the GEC design, but hey what do I know.
            soldering stuff that's broken, breaking stuff that works, Yeah!

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            • #7
              We had the RCA book over here, and they had sample circuits in the rear for all manner of things. You might recognize some of the circuits in Fender amps as direct lifts from RCA. But this was not a secret, the RCA folks put designs in the book precisely to be taken. They wanted to make it easy for potential manufacturers to design things, and in the process use lots of RCA tubes. All the tube plants did this.

              Just like nowdays, you see a data sheet for an LM3886 or a TDA7293 and then spot the identical circuit in some amp. That is why the data sheet included the circuit.

              There is no shame in not re-inventing the wheel.
              Education is what you're left with after you have forgotten what you have learned.

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              • #8
                The GEC Book has a monster 500W 10 x KT88 amp - It uses two stages of amplification between the PI and the output valves, so not much resemblance to the Marshall 200 circuit.

                The other high power amps in that book all use RF transmitter valves with HT Voltages of up to 2.5kV.

                The book goes into some depth comparing the pros and cons of large numbers of parallel KT88s vs. the use of pairs of monster transmitter valves.

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                • #9
                  Originally posted by Enzo View Post
                  We had the RCA book over here, and they had sample circuits in the rear for all manner of things.
                  Mullard did the same for amp designs and they still hold up today. All kinds of manufacturers used their circuits, from radio and TV to Hi-Fi. Mullard was held in such High esteem that companies used this as a selling point. At the end of the day, they wanted to sell more valves, but in the process they published a lot of really good technical information. Here's one of their books 'Mullard Circuits for Audio Amplifiers';

                  https://www.google.co.uk/url?sa=t&rc...mdyoLw&cad=rja

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