JMP 2104 Speakers

Cstell

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I just purchased a 1978 JMP 2104 combo, and it is killer. I had a question on the speakers in it, and I was hoping someone could help me out. They have a black Marshall label on the magnet. Are these blackbacks? Is there any difference between a blackback and a Greenback?
 

Emiel

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Properly a pair of G12-65s. You can do worse!

Here's a comparison with some Greenbacks...

 

neikeel

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Pictures of the speakers, frame stamps and cone codes - please!
 

V-man

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My 78 412 has Blackbacks in it. My guess is you may be more likely to have those, although 65s make more sense for amp safety in a combo.
 

StingRay85

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Since they have a black label on the magnet, the answer is G12-65.

Blackbacks have a black plastic magnet cover, and that's not what OP referred to.
 

Super Blead

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Never seen '78 2104s with G12-65. Not before '79.
Maybe the OP just forgot to talk about the black magnet covers.
 
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GIBSON67

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There were some G12-65's made in 1978, but from what I've seen the Marshall labeled -65's didn't start until 1979. But please show us some pics, maybe that will change.
 

Super Blead

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Thanks for the replies everyone…So, it looks like a T1221 code on there. That should be a G12M right?
Yes, G12M Blackbacks lead cone from May '78 (the 17th! Happy birthday to you G12M! :applause:).
You should see 1777 code stamped on the cones.
 

StingRay85

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Never seen '78 2104s with G12-65. Not before '79.
Maybe the OP just forgot to talk about the black magnet covers.
Or the speakers were not original to the combo. Anyway it was your last prediction, blackbacks it is
 


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