1968 JMP Super PA, 100W head - or something...

[Nik Henville]

This is on the bay of Flea here in Blighty...

https://www.ebay.co.uk/itm/Vintage-...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

...and I was wondering

 

[Ken Underwood]

And guess what Nik, red and black and not original or early LOL

 

[Nik Henville]

And guess what Nik, red and black and not original or early LOLView attachment 69003

Dear Ken,
Say what now...? I think you are confusing me with someone else in another thread.
I have never commented on wiring colours in ANY Marshall amps - not my thing...
...others herein may well have done so. I merely related MY wiring of MY builds for the NHS.
And the choice of black/white was my boss's rules - now he WAS old school.
His mantra was "red is hot, black is not, green and yellow earths the lot".
I asked him why black/white for EHT - he said red was live mains, white was hot, hot, hot

 

[BanditPanda]

And guess what Nik, red and black and not original or early LOLView attachment 69003

Hi Ken

In the e bay posting of the amp in question the description reads:
"It has been recently rewired by a very good amp tech to a standard 100 watt Marshall circuit as per the attached drawing.|
and
"As this amp has lost its original circuitry it is offered for sale as a potential restoration project and is sold as seen."

BP

 

[Ken Underwood]

Dear Ken,
Say what now...? I think you are confusing me with someone else in another thread.
I have never commented on wiring colours in ANY Marshall amps - not my thing...
...others herein may well have done so. I merely related MY wiring of MY builds for the NHS.
And the choice of black/white was my boss's rules - now he WAS old school.
His mantra was "red is hot, black is not, green and yellow earths the lot".
I asked him why black/white for EHT - he said red was live mains, white was hot, hot, hot

No Nik you got the wrong end of the stick, i looked at the ebay ad and there was two on there, this one had the picture of the underside of the chassis,so you can see what jumped out at me.

I commented on an old thread earlier today were it was mentioned that early Marshall's had black and white twisted heater cables, i pointed out that there is a difference between the words Early and Original.

Think some guys here think i am telling porkies, why should i want to do that.

Guys, not all but some, i was there, honestly, and i know that some of you think that i am making up, well you are entitled to your opinions, thats fine by me.

 

[Ken Underwood]

This is on the bay of Flea here in Blighty...

https://www.ebay.co.uk/itm/Vintage-Marshall-Plexi-Super-PA100-JMP-JTM-Amp-model-circa-1968/293507555859?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

...and I was wondering

I am wondering too Nik

 

[Ken Underwood]

Hi Ken

In the e bay posting of the amp in question the description reads:
"It has been recently rewired by a very good amp tech to a standard 100 watt Marshall circuit as per the attached drawing.|
and
"As this amp has lost its original circuitry it is offered for sale as a potential restoration project and is sold as seen."

BP

BP we are talking about a different amp mate https://www.ebay.co.uk/itm/Marshall...a=1&pg=2334524&_trksid=p2334524.c100667.m2042

 

[neikeel]

The amp has been gutted totally, something strange has been done to the top of the chassis too.
If you were to buy it that would be for the value of the headcab, panels only.
Presume that the circuit boards and original parts went to a rebuild of something else.
The schem in the photo is not even of the correct amp.
At least the description make it clear that it has been re hashed.
Can't tell if the transformers are original or not from those pics - might be useful?

 

[Nik Henville]

Quite agree, @neikeel - but it has intrigued me...
...and the state of the cabinet... kinda matches my LP

 

[BanditPanda]

BP we are talking about a different amp mate https://www.ebay.co.uk/itm/Marshall-Master-PA-100w-4-channel-head-EL34-vintage-valve-amplifier-tube-amp-JMP/202772875216?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20160811114145&meid=eacabacd036b4a6da1dc2e84f876c72e&pid=100667&rk=2&rkt=8&mehot=none&sd=293507555859&itm=202772875216&pmt=0&noa=1&pg=2334524&_trksid=p2334524.c100667.m2042

Sorry 'bout that. Between Nik, you and me I'm totally confused! No matter. Carry on.
BP

 

[Seanxk]

Quite agree, @neikeel - but it has intrigued me...
...and the state of the cabinet... kinda matches my LP

Me too, the transformers could be right, but why the PT bell is in such good condition, re plated perhaps or just all new, really need to see a pic underneath.

 

[Nik Henville]

I suspect, but don't know, that it is not even a Marshall inside there...
...just some parts - or even most - of another amp stuffed inside a cannibalised shell.
Kinda like a Taco-Bell taco of the amp world. Whatever... I think (even at the current low price) I won't go there.

Still interested in what other, more knowledgeable, folk see in there...

 

[ampmadscientist]

I suspect, but don't know, that it is not even a Marshall inside there...
...just some parts - or even most - of another amp stuffed inside a cannibalised shell.
Kinda like a Taco-Bell taco of the amp world. Whatever... I think (even at the current low price) I won't go there.

Still interested in what other, more knowledgeable, folk see in there...

From what I can see the whole inside is replaced / rewired. The only thing original is the chassis and transformers, maybe a few other parts.
It's not a Marshall amp but it is a Marshall chassis.

 

[Nik Henville]

It's not a Marshall amp but it is a Marshall chassis

That's about where I had got to...
I suspect whatever Marshall parts may be left behind
will not be enough to make it sound like a Marshall Super PA

So it boils down to "do I want that mojo in the cabinet?" - to which the answer is "Probably not..."

 

[ampmadscientist]

That's about where I had got to...
I suspect whatever Marshall parts may be left behind
will not be enough to make it sound like a Marshall Super PA

So it boils down to "do I want that mojo in the cabinet?" - to which the answer is "Probably not..."

It's only a shell of it's former self.

 

[Ken Underwood]

And very poor wiring as well, thats the give away for me.

 

[ampmadscientist]

And very poor wiring as well, thats the give away for me.

It looks like my first grade science project.

 

[Matthews Guitars]

It'd be a great box to build your own amp in. The transformers are nice, if they're good.