Help identifying vintage Marshall

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Hi All. New on this forum. Amazing site!
I have had this amp for a few years now and was told it was a '68 when I bought it. It came with 2, 4-12 cabs. I verified the speakers were originals - date coded 1969.
The amp has a serial number. It also has CSA on the tag. Is this normal for N. American amps? One tube is an original Marshall....the rest are newer.
So what do I have here lol.
Thanks!

Need to figure out how to add pics! Please stand by...
1968
I guess There’s no voltage selection because it was specifically made for Canada?
 

Gene Ballzz

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@Jimmy Bodanis ,
It may be worth the hassle and expense to get/ship it of to @neikeel (or someone as well experienced, though I don't know who) for a complete going through, re-furb, etc. The actual monetary value will likely be increased by far more than the expenses incurred AND/OR if you're going to play/use it, the enjoyment factor will probably be greatly enhanced!
Just My Addled Perspective,
Gene
 

Matthews Guitars

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Not wishing to argue, but it says JTM45 right on the back panel. So it stands to reason that it's a JTM45 and not a 1987.

A JTM45 is actually about a 35 watt amp due to the power output limitations of its tube rectifiier.

It'd be nice if you put up photos showing the entire chassis from the top showing ALL of it in one photo.
 

Derrick111

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Not wishing to argue, but it says JTM45 right on the back panel. So it stands to reason that it's a JTM45 and not a 1987.

A JTM45 is actually about a 35 watt amp due to the power output limitations of its tube rectifiier.

It'd be nice if you put up photos showing the entire chassis from the top showing ALL of it in one photo.

No, not a JTM-45. It has a 784-139 output transformer ((EL-34s) and no tube rectifier, and split cathode preamp, and, and, and... I could go on. The CSA tag likely says it because Marshall was using up old CSA tags that were printed for the later JTM-45s. But those ams would be quite different form this one indeed.
 

Matthews Guitars

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Ah, that explains it. I'd have normally expected Marshall's own label to be correct, though. There's being economical...and then there's just being LAZY.
 

Jimmy Bodanis

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Been asked for a pic of the cabinets. I got these and the amp as a package from a local guy here in Toronto. They are both 4x12 slant cabs with the original speakers.
They have seen many, many gigs and are kind of beat-up....but they still sound great!
 

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Jimmy Bodanis

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@Jimmy Bodanis ,
It may be worth the hassle and expense to get/ship it of to @neikeel (or someone as well experienced, though I don't know who) for a complete going through, re-furb, etc. The actual monetary value will likely be increased by far more than the expenses incurred AND/OR if you're going to play/use it, the enjoyment factor will probably be greatly enhanced!
Just My Addled Perspective,
Gene
Thanks! I agree. I like my stuff to be as right as possible. I am in Toronto - but I would ship it to someone who can straighten it out for me.
 

Jimmy Bodanis

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Looks like a late 68 Canadian Market JMP5 Model 1987.
It has had some messing with for servicing etc but apart form the rectifier looks pretty original (can't say for sure regarding OT yet - need more pics).
Thank you very much!!
 

Derrick111

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Ah, that explains it. I'd have normally expected Marshall's own label to be correct, though. There's being economical...and then there's just being LAZY.
Yes, you would think... Its not the only time Marshall did this. They continued using up the stock of 260w badges for their speaker cabs after they made the switch from 65w Celestions to 70w, then 75w Celestions until they either got new ones or used up the old ones. Fender did the same thing with their combo badges where the circuit type and design date/model wouldn't track with the changes because they used up remaining stock. Marshall did this with cosmetics sometimes too. Park used up old style parts so often had much earlier cosmetics. Though the change from JMP to JCM is well documented as 1981, Marshall continued to make old style JMPs for Sweden well into the mid 1980s. Gotta love manufacturing practices...
 

Matthews Guitars

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Mesa took their stock of Mark IIC front panels and had extra legends silk screened on them for the new incoming Mark IIIs. They DID spend the money to get that done, though.

Every company tries to save some money where they can.

But the model plate? It's wrong, use it anyway? That strikes me as being excessively cheap.

It'd be like buying a new Toyota model that replaced the Camry but it has Camry badges on it because they've got plenty of them and the new badges don't arrive until next month.

Oh well. It's just something else to look for when trying to ID an old Marshall.

I really think Marshall never made 100 identical amps in a row in the JMP and earlier days. Something would change before the 100th one was completed.
 

Jimmy Bodanis

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Knowing what I know about CSA, they were big time sticklers on the approval process for electrical products. CSA (or a special one-off test) was a requirement to sell into the Canadian market back then....up until early 2000's when there was a harmonization of approvals in N. America between CSA, UL, ETL etc.
My guess? Marshall already had CSA approval on the one model and put that tag on others so they didn't have to go through the long and expensive approval process on another model.
 
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CptZar

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Not wishing to argue, but it says JTM45 right on the back panel. So it stands to reason that it's a JTM45 and not a 1987.

A JTM45 is actually about a 35 watt amp due to the power output limitations of its tube rectifiier.

It'd be nice if you put up photos showing the entire chassis from the top showing ALL of it in one photo.

I would have thought a 1987 was lead circuit and a 1986 was a bass circuit? Other than that, this appears to be a JMP50 , as written on the front panel.

Model numberWattsDatesFeaturesNotes
JTM4535–45[10]1963–19642 channels, 4 inputsAlso available in bass and PA versions
1963501965–19664 channels, 8 inputsPA version; "JTM50 MK III"
1985451965–19662 channels, 4 inputsPA version of JTM50 MK II
1986451965–1966High treble and normal channelsBass version of JTM50 MK II
1987451965–1966High treble and normal channelsLead version of JTM50 MK II; also with tremolo as Model T1987
1989451965–1966For electronic organsAlso with tremolo as Model T1989
JTM 45 (2245[11])301989–2 channels, 4 inputsReissue of original JTM45 (1987)
 
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Derrick111

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Every company tries to save some money where they can.

But the model plate? It's wrong, use it anyway? That strikes me as being excessively cheap.

That CSA tag wasn't Marshall's usual model identification. I believe that they relied on the front panel to identify the model more so than the a CSA tag which went on the relatively low percentage of their amps that being made for the Canadian market. That would also explain why they had old plates to use up. His amp does say "JMP" right on the front... the model, much like how you would expect to see a Toyota emblem on the top front of the hood as apposed to the interior door compartment.

My guess? Marshall already had CSA approval on the one model and put that tag on others so they didn't have to go through the long and expensive approval process on another model.

Jimmy, the JTM-45 preceded your model 1987 however, so the 1987 was an evolutionary progression from the JTM-45 that existed a few years before your amp. When Marshall produced a batch for the CSA market, it seems they had these tags left over form the JTM-45s and used them.
 

Gene Ballzz

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Jimmy, the JTM-45 preceded your model 1987 however, so the 1987 was an evolutionary progression from the JTM-45 that existed a few years before your amp. When Marshall produced a batch for the CSA market, it seems they had these tags left over form the JTM-45s and used them.

Wouldn't this somewhat equate to an attempt to defraud or otherwise circumvent government regulations? As I've been led to understand UL standards, much of it pertains to any circuit that has AC applied to it from the wall Alternating Current and has been modified from the original, tested, listed design. It does not pertain to the DC part of the circuit, only to the portion of the circuit that is prior to and including the coversion from AC to DC. This is what has spawned the prevalence of "wall warts" for so much electronic gear. A company only needs to have that outboard power supply inspected, tested, certified and listed once and can continue to use that same wall wart/power supply on any multiples of various models and units, with annual changes to all the rest of the circuitry not even being inspected. Perfect examples are the DBX consumer lines of gear, as well as BOSS pedals that have used the same wall warts for eons. There are no UL or CSA listings on the units themselves, only on the wall warts!
Just Wonderin'?
Gene
 

Derrick111

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Wouldn't this somewhat equate to an attempt to defraud or otherwise circumvent government regulations? As I've been led to understand UL standards, much of it pertains to any circuit that has AC applied to it from the wall Alternating Current and has been modified from the original, tested, listed design. It does not pertain to the DC part of the circuit, only to the portion of the circuit that is prior to and including the coversion from AC to DC. This is what has spawned the prevalence of "wall warts" for so much electronic gear. A company only needs to have that outboard power supply inspected, tested, certified and listed once and can continue to use that same wall wart/power supply on any multiples of various models and units, with annual changes to all the rest of the circuitry not even being inspected. Perfect examples are the DBX consumer lines of gear, as well as BOSS pedals that have used the same wall warts for eons. There are no UL or CSA listings on the units themselves, only on the wall warts!
Just Wonderin'?
Gene
Hi Gene. I can only speculate as I wasn't there or part of the process. I would think that (1) things were much less strict back then, and (2) that the amp was indeed built to CSA spec, but that they simply didn't have "JMP" labeled tags to accurately point this Marshall's model designation. Surely, the amps were still in accordance with CSA regardles of the accuracy of Marshall's model naming designations, and the designation Marshall used may not have any effect on the listing.
 

Gene Ballzz

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Hi Gene. I can only speculate as I wasn't there or part of the process. I would think that (1) things were much less strict back then, and (2) that the amp was indeed built to CSA spec, but that they simply didn't have "JMP" labeled tags to accurately point this Marshall's model designation. Surely, the amps were still in accordance with CSA regardles of the accuracy of Marshall's model naming designations, and the designation Marshall used may not have any effect on the listing.

Yeah, but part of the method of converting AC to DC was changed from being done by a tube/valve to being done by SS diode rectification. It might have something to do with some "grey area" concerning what happens prior to the transformer vs after? Or maybe the term "diode" was construed in the regulations to include both tube and solid state "diodes" as certain portions of tube rectifiers are referred to and function as "diodes?"

Either way, using up government approved and/or produced labels on units that were only "similar" seems to at least border on being a bit shady, or questionable at best! Where does one draw the actual line between compliance and skirting regulations? I guess that is for attorneys to argue!

I Was Just Curious,
Gene
 


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