Uh oh...why do I think of stoopid projects?

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shadyshady Frets: 252
Basically, I have a hair brained idea to turn my 90's Marshall 3x10 JTM60 combo into a head and 4x10 cab.  Why?  Exactly...I dunno, I don't gig, just for loud home use.

Anyway - a handy mate of mine is able to make an enclosure for the ampy bit thus leaving more room in the cabinet for another speaker.  Now, I reckon that'll make for quite a good sounding compact package.  Obviously a bit of work involved in this, new grill cloth, new baffle, wiring etc etc.  I have me birthday next month so some cash may well be spunked on new speakers and to this end, 60 watts with a total load of 16ohms,  the choice of possible combinations has me confused.  I have read a few articles on the subject and as I'd like to keep things Marshally going Celestion would make sense.  Golds are well out of my price range though!

Aside from the actual stupidity of such an undertaking, is there any advice you lot might offer as far as 10 inch speakers go?


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Comments

  • shadyshady Frets: 252
    Blimey Charlie.  This is going to be too expensive I think.  As a bundle, 4x Celestion G10N-40 is the cheapest from Lean Business.  I also presume that 4x16ohm wired series/parallel is the only way to go with this, unless I make use of the external speaker out, but that that's just not cricket...or any other sport...and I don't like cricket anyway.
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  • olafgartenolafgarten Frets: 1648
    edited December 2016
    If you want 4x10 with 16 ohms impedance there is 2 options, either 4, 4 ohm speakers in series or 4 16 ohm speakers in a series parallel hybrid wiring. 

    That would be something like this:
    Tip of Jack (Positive) -> Speaker 4 Positive
    Sleeve of Jack (Negative) -> Speaker 1 Negative
    Speaker 1 Positive -> Speaker 2 Negative
    Speaker 1 Negative -> Speaker 3 Negative 
    Speaker 2 Positive -> Speaker 4 Positive 
    Speaker 3 Positive -> Speaker 4 Negative
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  • shadyshady Frets: 252
    edited December 2016
    Yip, thanks for that...been schooling myself on various wiring diagrams.  4ohm 10" guitar speakers don't appear to exist, bass yes, guitar no.

    *EDIT* The Tayden True Brit is 4ohms, £60 a pop though.
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  • Winny_PoohWinny_Pooh Frets: 7730
    edited December 2016
    Dont do it. If you want a project then build an Ampmaker head kit.
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  • shadyshady Frets: 252
    If I can't find a set of decent enough speakers at good price then it won't happen. It's not like it's a particularly well built amp in the first place and certainly wouldn't do any harm as a bit of a sex up project, as long as the outlay is minimal. I'm in no hurry, getting the head enclosure built is the first step anyway - and the catalyst for how the rest of it looks.
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  • gubblegubble Frets: 1737
    This might sound crazy but would it be easier to sell your current JTM60 combo and hunt down the head and 4x10 cab version they did?
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  • ICBMICBM Frets: 71951
    gubble said:
    This might sound crazy but would it be easier to sell your current JTM60 combo and hunt down the head and 4x10 cab version they did?
    This.

    On the other hand if you really want a project, go the whole way and build a completely new cabinet - that way you can use ply, and ditch the crappy MDF shell Marshall used.

    If I remember rightly the speakers in these are Eminences (they are in the other models), so either you want to find a similar Eminence as close as possible to the existing ones, or replace two or all four - a single different speaker in a set of four usually sounds odd.

    I also worry that you'll go to a lot of trouble and expense and then the amp section will die, too… they have a tendency to, although they can be repaired at some cost. If you're going to make a head box for the amp section, make sure it's really well-ventilated, including a top vent - I don't normally like them but these amps have a bad record for overheating.

    "Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski

    "Just because I don't care, doesn't mean I don't understand." - Homer Simpson

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  • shadyshady Frets: 252
    I've been scouring the interwebs for everything you gents have mentioned above over the last couple of evenings.  

    The JTMC 4x10 seems a rare beastie and most of the heads have probably gone to the great gig in the sky along with it's slightly younger and short lived JCM600 sibling.  As the 3x10 Eminence speakers are rated at 5.3ohms each to get 16ohms the only way forward would be a complete replacement, which is prohibitively expensive for what is (as much as I like it) a mediocre amp notwithstanding the well documented issues.  But my thinking is if/when the amp implodes I would then have a half about cab to partner a replacement head.

    Marshall also did a 15" combo, which got me thinking I could find a cheap knackered one and use that as an extension cab but they seem harder still to find - one on Ebay for £495 though...not exactly a bargain.

    Meh...as you might expect, the usual places will be kept an eye on for 2nd hand shiz.  Keeps me interested innit.
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