Cool Amp Spotting! Pete Townshend´s 100 Dual Rectifier Dual Output 100w Amp

Discussion in 'Let's Talk Vintage' started by pleximaster, Jun 9, 2018.

  1. pleximaster

    pleximaster Well-Known Member

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    Let´s try this thread again!
    This thread was mistakenly deleted/lost during the change of server of the forum according to the moderator. I first thought I had violated some rule by posting these pics that I got from a friend the other day. It is supposed to have belonged to Pete Townshend of the Who and has a interesting story and one of the first 100 watters design by Dudley Craven and Ken Bran.

    My friend wrote this about it. I have tried to fix the text from google translate as it originally was in Swedish... :)

    “This is a cool early dual output 100 watt Marshall amp with dual rectifier tubes. It was probably one of the first 100 watters signed off in May 1965 for Pete Townshend as indicated by inspection tag. This amp predates other dual output amps as it sports the twin GZ34 valves instead of the later diode rectified 100 watters. It is not a pure prototype but could be consider a “pre-test-production” run. The cab is interesting as it has a full length width but is only as tall as previous jtm45s. It doesn’t have the tremolo section that Pete later recommended that they included for these amps. Pete went through quite a number of amps. This has Pete´s name and a reference Super Amplifier No7 written on it. Is it Pete´s 7th amp or the 7th100 watt amp?

    This amp has had a hard life and was restored pretty hard 10-15 years ago; removal of master, retolex, new strap handle new modern Marshall knobs (should be Clapton knobs, one remains) later choke, output covers transformers? and more.

    Cool anecdote, it is legendry the amp that Pete Townshend, while upset, picked out of his van and though at Terry Marshall after a dispute around unpaid bills, an argument that eventually led to the fact that Pete departed from Marshall, and saying “it doesn’t work and it sounds like shit anyway!” :)

    5-6 years ago, the MT unfortunately had a melt down and brought down at least one of the output transformers. You can see how the laminations of the OT have warped as it got hot. Current owner doesn’t want to restore it as of its historical reference. “

    Other info:
    The amp is in a private collection in Germany.

    The two valve/tube sockets behind the MT are for set parallel set of GZ34 rectifier valves. The four remaining octal bases are for KT66 (however it had EL34 when it melted the OT which could have been the reason for the malfunction.) Preamp valves should be ecc83s as usual.

    The OTs are wired in parallel as well

    Cabinet is recovered but the interesting thing is that the cabinet is a mixture of a traditional small box (height and plywood thickness) but full length chassis and box length as the 100 watt cabinets we are familiar with.

    The capacitor layout is also unique having six 32uf caps on a board and a extra 16uf cap (like traditional jtm45s) mounted with a clip on the side next to the fuse holder and the MT.

    Serial number is in the 6000 range.

    plexi

    PT1.JPG PT2.JPG PT3.JPG PT4.JPG PT5.JPG PT6.JPG PT7.JPG PT8.JPG PT9.JPG
     
  2. jmp45

    jmp45 Well-Known Member

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    Very cool. I expected to see this in disrepair. Awesome piece of history.
     
  3. tomsvintage

    tomsvintage Well-Known Member

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    Pleximaster , Thank you for posting this rare and very significant piece of Marshall history !!!!
     
  4. neikeel

    neikeel Well-Known Member

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    Very, very interesting I have never seen a dual Gz34 45/100 before or one with block logo except in 'The Who' photographs (there was that one in Italy with bass label).
    I did quite a lot of research as I am in possession of Ser.6503 which has prototype features (odd cap board) but it is a PA with script logo and RS Deluxe PT but a pair of Drake 789-74 OTs. The primaries are in parallel as are the secondaries because the output jacks or linked.
     
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  5. charveldan

    charveldan Well-Known Member

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    Somewhere with a Friedman Marshall & Les Paul.
    I thought it was deleted because the amp may be stolen ...


    This amp would be cooler if it worked.
     
  6. pleximaster

    pleximaster Well-Known Member

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    Me too! I the original thread we were discussing the early 100 watt amps that were stolen from the who while in Sweden...

    plexi
     
  7. pleximaster

    pleximaster Well-Known Member

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    Lot of interesting features to be sure.

    I guess the big chunky RS MT used in later 100 watt amps won´t fit the in a head box cabinet with the lower height of this box and other traditional jtm45 small boxes and that the reason for increased height of 100 watt head boxes. This suggests that the odd (unfortunately blown MT in this amp) is original. Another thing I just saw when studying the pics are there probably isn't a CT on the 6.3V heaters on this MT. Isn't there an artificial ground (resistors from heaters going to ground) ?

    First marshall with Vox vents?

    I also wonder the reason for having wires from the OTs going above the chassis? Why?

    the OTs have ohm selectors on them but have five holes for mounting screws I never seen that before only with two centre ones. Replaced or original? looks old but... :)

    plexi
     
  8. Marshallhead

    Marshallhead Well-Known Member

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    Is there any information on where it came from?
     
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  9. pleximaster

    pleximaster Well-Known Member

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    I can ask my friend if his got more info on that. When we spoke the other day he mentioned that the current owner bought it working restored condition in early 2000s in Berlin. From where who what we didn't go into? I don´t know. I had many other questions... :)

    plexi
     
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  10. GrahamL

    GrahamL Active Member

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    Cool... regarding the amps being stolen, its a big "Who" done it! bu da bum bum :band:
     
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  11. neikeel

    neikeel Well-Known Member

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    Re: the selector in trannies the ones here are two hole mounts both have 4, 8 and 16ohm options. As you noted the primaries run up top and are plaited and laced.
    I presume you have one of the big RS pt amps in your arsenal?
    I don’t recognise the PT in the amp above, does not look like the later Drake 1203-80 that came in after the RS.
    Oh and the boards in that pic look really red ?
     
  12. pleximaster

    pleximaster Well-Known Member

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    So Whats your thoughts on the ot covers? Ots?

    I actually downt have a big rs MT 100 watt amp, its on my to get list!

    Boards dont look alarmingly red on my screens and my friend who’ve seen the amp didn’t mention anything odd about the boards and he has great experience

    I see from other dual amps that the primaries of the ot are on top. Still don’t get why? Looks like bad design

    Plexi
     
  13. Ned B

    Ned B Member

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    The blown PT looks like a 1204-43 which came before the 1203-80 and is a good half inch taller. Maybe it was a prototype from Drake with the RS type used until full production established.
     
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  14. neikeel

    neikeel Well-Known Member

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    Sorry Ned I meant -43 (Sunday am brainfade waiting for kettle to boil). Still came after the RS.
     
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  15. danfrank

    danfrank Well-Known Member

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    Thank you Pleximaster for sharing this with the MF. Very interesting history!
     
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  16. pleximaster

    pleximaster Well-Known Member

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    Got some more info on this from my friend who visited the current owner in Germany. It has amp more celebrity connections!


    “After the “return” to Marshall the amp came to the guitarist Derek Leckenby, who played in the British band from Manchester Herman's Hermits. He really didn´t use it much as the band departed to the US were they used Fender amps, Herman Hermits were part of the British Invasion. In the mid 70´s the amp was sold to the famous recording studio in Berlin the “Hansa Tonstudio”, (still operational today) where it was also used as a rental amp for touring bands. In the late 80´s early 90´s something it was lost for a few years as it was out on tour but later surfaced again and came in possession of a musician named Thomas Gruhlke. It was recognised as an historical interesting amp and was restored by a “Dr Music Meistro” in Berlin as indicated by the sticker on the back. About 10-15 years it was bought by the current owner and was operational then. Broke down 5-6 years ago and left as is. Serial is 65XX (Owner doesn’t want it out. but it´s a low number but not 6500, panels were probably not picked number order.) This is part of the first 100 watt white panels batch made, which all originally had Super Amplifier PA silkscreened on them, the PA was removed on non PA models and sometimes a “100” was added (different font and gold color) as well a “LEAD” “PA” above the serial number.”

    Just for verification of this PA panel thing I have looked at another friend dual output amp No 6539, definitely original and the actual Dual Output amp that Marshall used for blueprinting the dual output reissue (minus the trem part) this amp has been speculated to have been one of two dual output amps that Pete Townshend lost while touring in Sweden (that’s a whole new thread by its own… ☺) Look at the close up of this amp and you see a “PA” shadow under the “100” lettering
    more pictures of this amp you can see on the amparchives and JTM45/100 super tremolo dual output.

    plexi
     

    Attached Files:

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  17. pleximaster

    pleximaster Well-Known Member

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  18. pleximaster

    pleximaster Well-Known Member

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    My friend has made a deal on this amp and is picking it up after the "Swedish midsummer holiday" (the upcoming weekend.) And I have made a deal with him too! I have promised to fix it up for him for free and I get tro trace, out line it, measure everything up and making blue print of it!!! Cool! :)

    It seems to have originally had 6L6 tubes and not KT66 in it. it was probably the el34 that killed the MT as they draw more current. Reason we believe KT66 was´t in it originally... The valves don´t fit proper when the chassi is put in the box!

    This is also in line with the early amp shown in the Marshall book page 33 that have 6L6 valves (even though the same amp has KT66 in the coloured pages...) On page 34, the Doyle book describes a prototype with four 6L6 and two GZ34, are they talking about this amp? Perhaps?

    Marshall made a 4x6L6 tube amp with dual rectifiers before MESA! Haha!

    plexi
     
  19. pleximaster

    pleximaster Well-Known Member

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    I am already in the measuring up the amp mode!

    I’d like to get every component described as following

    Brand
    Originally
    Date codes (when available)
    Stamped value
    Meassured value
    Oddities

    Do you guys have any good trixs to measure components in these amps with minimum of tampering with solder joints

    Transformers must be removed anyway so there we have some things that will help measure some components in specific positions

    The preamp however and som coupling caps are harder to measure without tampering

    Potentiometers as well, they influence the tonestack a lot...

    Ideas? How would you go about measure this thing up. I’d might like to make a clone out if it for myself. It looks soooooooo cool with 9 valves/tubes in a long row...

    Dan frank
    Transformers guru!!!
    What would you do with the warped MT?

    Plexi
     
  20. neikeel

    neikeel Well-Known Member

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    Neither of those output transformers look like original units to me, as you know the choke is mid 70s or later too. The original would have been the RS 20H or Drake 3H - the hole centres are slightly different IIRC. The 6 hole covers and the remaining selector looks odd (is that brown paxolin - ie '68MY) on limited pics I have seen.
    Will watch this with great interest!
     
    Last edited: Jun 20, 2018

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