JMP's

[siggy14]

OK is there really a difference between the JMP's. I was at a music store tonight and the owner, who deals mostly in vintage says that there is a different between the JMP's, the one with the small logo's he says sound better and are slightly different, i believe he said the switch over was 78. Anyone can shed light on this subject i would be happy.

Thanks,

Todd

[442w30]

Re: JMP\'s

The smaller logo provides less resistance to airflow. Makes sense to me.





Seriously I didn't ever hear that before

[Rupe]

Re: JMP\'s

They almost all sound a bit different...even the same model made the same year. Always try to play a vintage Marshall before buying...some have mojo, some don't (although some "poor" sounding ones can be made to sound great with some tweaking).

[charvelguy]

Re: JMP\'s

[ QUOTE ]
They almost all sound a bit different...even the same model made the same year. Always try to play a vintage Marshall before buying...some have mojo, some don't (although some "poor" sounding ones can be made to sound great with some tweaking).

[/ QUOTE ]

quite true, I think every Marshall can be of different character not just in how it is setup, but the amp itself has its own character. The changeover occured in '77, actually late I think '76 they were producing the master vol 'script' JMP's. Those usually have 4 inputs. They still made plenty of non master amps in '76.
They made them with red print on the back of the chassis and different stylings as well. I think the red print came in around 1979-1980 just before JCM's.

I have a couple non master 50's, and one master 50.
My fav is a reissue made for one year in '88 called a 1987S, which is patterned after a '73. The other is a non master '74. I've owned other 50's and a 70's superlead as well.
Then I have a '78 master. I personally did not like these amps when they were introduced.
To me, (and it may be me) this amp seems less loud than the other JMP's even when put at the same vol.
I think tonally they sound like a Marshall but have a little less headroom than a 4 input JMP. The amp still sounds good, but I agree the master vol do sound a little different.

[siggy14]

Re: JMP\'s

Here is some Info I have found, keep in mind the MV JMP 2204/2203's started production in 1976

"Further brightening of the circuits occurred in the 1979-1981 JMP master volume models in addition to the non- master volume models. I believe this is due to the incorporation of a new style of capacitor which was now a square plastic type. Again, in stock configuration, the higher-output pickups which inherently have emphasized bass but reduced highs seem to “balance” out the circuit. The ’79-’81 models are easily identifiable since they marked the beginning of Marshall adding its serial numbers on the amplifier front panels beneath the power and standby switches. Even with the minor circuit tweaks that only amount to a personal preference toward the ’77-’78 models, the ’79-81 amps were still punchy, and great all around rock and roll amplifiers. Combo versions in 2 x 12 and 1 x 12 versions also gained popularity during this era."

How accurate this is i am not sure as i got it fromt his webstie, you can read more about marshalls here. http://www.legendarytones.com/marsha...rs_guide_2.htm

[charvelguy]

Re: JMP\'s

Interesting writing. I did not know they reduced the # of caps in the horizontal series, cheap bastards.

I think the master volume amps of 77-78 are brighter sounding than an older JMP. As stated in that article..brightness can be attributed to the caps they used, or didn't use...and/or later on... the caps needing replacement. If they made the amp even brighter voiced in '79 they must be really top endy..which would account for why I did not like these amps relative to the small script heads of the early 70's.

I've played some metal panel PTP amps that just didn't do it for me either,..they have alot of headroom and have to be screamin loud to sound good but for the most part I prefer the '73's and '74's as they are reputed to have 'more gain'. I know some guys really dig the '76 non master amps for the same claim because they were the last development in the series before the MV change.
I personally did not care for the JCM era drake transformers just from my limited personal experience.

[siggy14]

Re: JMP\'s

I personaly have two JCM800's, they sound good but the tone is not warm enough for me. I am not a big AFI fan, but if you checked out there last album i thought his tone was killer and he switched from Mesa DR rackmount to using a JMP, just not sure what year, but to me his tone was wicked.

[charvelguy]

Re: JMP\'s

Older JMP's are much warmer IMO, especially with EL34's. They have a very even tone across the spectrum with the mids enhanced just right.

[Chuckracer]

Re: JMP\'s

I really like the tone of my EL34 1980 JMP. It's the sweetest sounding Marshall I've had, and I've been through a bunch of 'em.
Very even, smooth, not harsh or cutting at all...good, strong bottom, nice presence. Good whallop, too!

[siggy14]

Re: JMP\'s

[ QUOTE ]
I really like the tone of my EL34 1980 JMP. It's the sweetest sounding Marshall I've had, and I've been through a bunch of 'em.
Very even, smooth, not harsh or cutting at all...good, strong bottom, nice presence. Good whallop, too!

[/ QUOTE ]

I have read alot of places and been told by many people that the 1979-1981 JMP is the same exact amp as the 1981 through 1983 JCM 800's. With that being said i have a 1982 JCM and i do love the tone, however i would love to hear a 1976 through 1978 JMP. This little shop around here has a 1977 in fawn tolex, they want like 2600 for the head and matching cabinet, way to high for me, but i am gonna go play it to see how it sounds.

[Chuckracer]

Re: JMP\'s

Ooo...there it is again. That phrase. "Exact same". We're talking about production Marshalls here. I'd be willing to bet you will not find two from ANY era that sound the "Exact Same".
That being said, my JMP sounds nothing like your JCM. Keep that in mind whilst persuing Marshall tones! There are as many variations on that theme as there are amps.

[siggy14]

Re: JMP\'s

[ QUOTE ]
Ooo...there it is again. That phrase. "Exact same". We're talking about production Marshalls here. I'd be willing to bet you will not find two from ANY era that sound the "Exact Same".
That being said, my JMP sounds nothing like your JCM. Keep that in mind whilst persuing Marshall tones! There are as many variations on that theme as there are amps.

[/ QUOTE ]

Tru amps from that age could sound very different. I just mean the circuit is exactly the same, now depending on who did the flying leads and length could determine tone difference etc..

[Chuckracer]

Re: JMP\'s

Not to mention component tolerances were not real tight.
I'm tellin ya, it's not that they "could" sound very different, it's that they DO sound very different.
I don't know how long you've been around old Marshalls, but I've was playing them in the late seventies. I learned from the "older" guys. Right from the beginnings, we would play dozens before we would buy one. Everybody was always digging for a "good" one. Every pawn shop around would always have two or three metal panel 1959's for $300 and us gear heads would have played them all at some point. When Marshall themselves started research for building the re-issue series, they examined LOTS of different Plexi's to find a couple really good ones to spec out and measure components, test transformers, and find out why they were so good sounding.

No two older Marshalls sound alike. They all are subtely different, and when you find a good one, you don't let it go. This is why I elected to mod my JMP with an effects loop and a second, footswitchable master volume instead of selling it and buying a VHT or something more versatile for live work. It's a really good one!

[rstites]

Re: JMP\'s

[ QUOTE ]
Not to mention component tolerances were not real tight.


[/ QUOTE ]

I'm sure that's where most of the difference lies. The difference in the flying leads wouldn't change anything sonicly without completely different layouts, but 20% tolerance caps and 10% tolerance resistors (not to mention differences in off-the-shelf production transformers) would add up to some huge differences in the actual implemented circuits.

I've never really bought all the hoopla about different years of Marshalls being vastly different from other years. I've played a lot of them and think most of the difference can be artibuted to the specific component values amp-to-amp, rather than small changes in the year-to-year schematics.

[speed monkey]

Re: JMP\'s

[ QUOTE ]
No two older Marshalls sound alike. They all are subtely different, and when you find a good one, you don't let it go. This is why I elected to mod my JMP with an effects loop and a second, footswitchable master volume instead of selling it and buying a VHT or something more versatile for live work. It's a really good one!

[/ QUOTE ]

Dude - would you give somebody else the opportunity to be right for a change ? instead of always just nailing it? sheeesh... [img]/images/graemlins/grin.gif[/img]

[img]/images/graemlins/headbang.gif[/img] [img]/images/graemlins/headbang.gif[/img] [img]/images/graemlins/headbang.gif[/img]

Steve E