1972 PTP JMP 50 watt. VERY nice NON-USA export model!

[Trapland]

This amp was built to stay in England. The label on USA export models say USA, this one says ENG. it also has a multi voltage LAY DOWN MAINS transformer. You can use is amp pretty much anywhere in the world.

It has a BULGIN mains plug, that was never allowed in the USA as a UL listed electrical device. Quite rare to see this in the USA. Someone either carried this amp home from England, or had it shipped by a Brit.

This amp left the factory with EL34s and not 6550s like God and Jim intended. Rose-Morris never infiltrated this amp.

Aside from normal maintenance parts, this amp is ALL ORIGINAL. most of the solder joints have the red/brown ink on them. A few have been touched, probably for test purposes, but all of the original tone generator parts are still there.

Ok how does is sound? Well I am running Russian tubes all around right now and it's sounds amazing. The volume goes from loud at 1 to really loud at 2. After 2 it doesn't get any louder, just more overdriven. It has SO MUCH GAIN! Comparing it to a JVM, its got plenty. I like a fair amount of gain when I play, and I usually run this amp at 6-7. 8-10 is too much gain for live use for me.

All the buzz about 1972 being the year when "plexis" became monsters are true.

Here in no particular order are all the pros and defects.

Cabinet is REALLY nice and clean. The inside of me cab and the back panel both have 21 marked in as the week of inspection. The head does too. It's all straight.

Some of th front panel lettering is wearing off. The "JMP" lettering didn't fit in the "new" large box cabinet and the J is worn. This is a VERY early large box. It has smooth levant and gold piping.

It has the rare large round feet. Have you ever seen these except in pictures?

Lay down mains. Cool. And useful since this amp is ready to go on 120 and not 110 like so many others from the earlier era.

It looks like the rectifier diodes and caps were replaced. Maybe not, they may have just been desoldered for testing. This amp has zero hum.

The inside is beautiful. All preamp parts seem to be original.

Original Bulgin mains plug is cracked and taped with 600 volt tape. This happened on almost every Bulgin plug that gets dropped. It works fine. Most collectors would rather the mains plug was original, so I never converted it.

I've owned this amp for about 7 years. I have gigged with it and its amazing, but its always been given royal treatment. Now, I need another gigging amp an amp going to look for a beat circuit board version so I don't have to worry.

I really DON'T have to sell this amp. I have others. I am offering it to collectors or those that want something special. I really would prefer a local sale, but I will ship. Mostly, I took some nice pictures and wanted the forum to see it. If you need it, its available for $2800 plus shipping. I know it's top dollar, but its an amazing amp.

I will consider LOCAL partial trade for other 70s-80s Marshall's. Its a nice way to upgrade your collection.

Pics to follow....

 

[Trapland]

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[chuckelator]

She's a beauty for sure. GL with the sale!

 

[Trapland]

Let me just mention that I don't mind if anyone wants to use these pictures while discussing vintage amps. Just don't claim it's yours unless it is.

 

[damienbeale]

Your bias supply is currently wired to the wrong side of the standby switch. For safety of the PT, this should be changed.

The red wire on the standby that connect directly to the board should be moved to either one of the bottom terminals so that your bias supply is unswitched.


Btw, that is a lot of money to ask for an amp that is not particularly original inside. You're getting darned close to clean plexi price there, and it's neither clean internally, nor as desireable as a plexi.

All of your touched up solder joints (with the exception of two possibly original Iskra resistors) show later fitted components. As for the diodes, none of these left the factory like that, and it would have had a bridge rectifier mounted on that stud on the board as opposed to diodes.

 

[surfguy13]

Very nice amp and these early '72 JMP 50s are nice!

Re the bulgin plug......I'd be tempted to buy a new plug and probably socket as well. They're widely available here in the UK and I've just replaced the socket on one of my old JMP 50s. Got a pair of 'new old stock' sockets (the size you need for your JMP) for £7.50.....these were still wrapped in the old brown waxed paper so they really are old stock. Takes 2 minutes to wire the socket in and the plug likewise. The new old stock bulgins seem to fit perfectly, really tight. And, unlike many of the well used 70s plugs, they won't just fall out!!

If you have any problem getting hold of them I'm happy to help but I would advise against using the amp with a badly cracked plug.

 

[Trapland]

Very nice amp and these early '72 JMP 50s are nice!

Re the bulgin plug......I'd be tempted to buy a new plug and probably socket as well. They're widely available here in the UK and I've just replaced the socket on one of my old JMP 50s. Got a pair of 'new old stock' sockets (the size you need for your JMP) for £7.50.....these were still wrapped in the old brown waxed paper so they really are old stock. Takes 2 minutes to wire the socket in and the plug likewise. The new old stock bulgins seem to fit perfectly, really tight. And, unlike many of the well used 70s plugs, they won't just fall out!!

If you have any problem getting hold of them I'm happy to help but I would advise against using the amp with a badly cracked plug.

I have had it fall out.. Hence sone extra wraps of tape. Replacing the plug hs been on my todo list for many years.. It's just a thing easily forgotten on an amp that's rarely moved. I play it fairly often, but almost never take it out anymore. My cracked plug has worked fine for many years even out to a few gigs. But I should replce it someday.

 

[damienbeale]

Also, it is worth mentioning, the right angled Bulgin plugs that you can find also have a strain relief for the cable, and are a much safer alternative to the standard straight plugs.

 

[surfguy13]

Also, it is worth mentioning, the right angled Bulgin plugs that you can find also have a strain relief for the cable, and are a much safer alternative to the standard straight plugs.

Totally agree.....I'd always go for a right angle bulgin if possible.

I'd get a new plug Trapland.......if it falls out when you're working the amp hard you can have issues. Not worth the risk on an old amp for a few £'s?

 

[soundboy57]

I just scored a similar head, from October 72, a week ago, or we would be making a deal...

Mine doesn't say USA on the tag, but I assume the polarity switch/power cable makes it so??

 

[Valvelust]

I never understood why they made them with "JMP" hidden behind the front cut out where you cant see it or it gets half rubbed off.

 

[Trapland]

I never understood why they made them with "JMP" hidden behind the front cut out where you cant see it or it gets half rubbed off.

My guess is that it was a printing issue. I think they didn't plan to need polarity switches on some models, so when they found out they needed the,, they just moved the JMP over with little regard for fit.


Then they all got it. It's a good thoery right?

 

[kamran]

I dont think a 72 is enough of a collectors piece to not convert it to a newer style mains plug.

 

[soundboy57]

I dont think a 72 is enough of a collectors piece to not convert it to a newer style mains plug.

Pre '73 tag board 50 watters in great cosmetic, and original condition, including transformers, are pretty tough to find.
Especially the '72...

I would put an original (and easily available) original mains plug in it,
and refrain from cutting or drilling for a newer style..

I looked for years to find a nice, unmolested 72.
And, they don't give the nice ones away, at least in the USA...metal panel or not.
They are classic Marshall...
as good as it gets for tone and crunch.

 

[soundboy57]

(edited)

...The volume goes from loud at 1 to really loud at 2. After 2 it doesn't get any louder, just more overdriven. It has SO MUCH GAIN!....
...All the buzz about 1972 being the year when "plexis" became monsters are true....

....

Yes, and yes.

Good luck with the sale!

 

[Trapland]

I dont think a 72 is enough of a collectors piece to not convert it to a newer style mains plug.

I think people that actually own one would generally disagree. 72 was a unique year, in so much that the amps suddenly became gain and crunch monsters while still maintaining the PTP wiring.

They are fairly rare to begin with. Then to find one that was never a USA model with the transitional lay down mains transformer, that has NOT been converted to a modern cord, well, that makes it very rare.

If it was converted to a modern main plug, then it would be just another Marshall that someone hacked some holes into.

I'm not trying to be sarcastic, really, but go find one like mine, then feel free to hack in some modern appliance receptical. Stuffing in the receptical is the easy part, cus you dont have to worry about it looking good, its gonna look like crap no matter what you do. The hard part is finding one to hack up.

 

[Trapland]

I just scored a similar head, from October 72, a week ago, or we would be making a deal...

Mine doesn't say USA on the tag, but I assume the polarity switch/power cable makes it so??
]

I was just reviewing this thread and.....

I think your tag actually DOES say USA on it. Look right below the word LEAD. It sure look like it says USA to me! Yes?

 

[Trapland]

The 72 is sold.