Marshall 9200/ JMP-1

[rzenc]

Got these on the bench...

Marshall 9200 - 2 channel 100W power amp - tubes are sovtek 5881 - seems to be factory original.. preamp tubes are ECC83, ECC81 - looks like chinese tubes...
Marshall JMP-1 preamp...

Friend bought them used back in 1998 - sold in 2003 - bought again last week... He told me it is sitting for about 5 years in the basement without use...Previous owner dropped both units on the floor - scratches on the faceplates and rack-ears...Also fired it without load attached  and some stuffs he was not proud to tell us

Tested tubes in my amp and they are varying all over the place.
Since tubes are locked inside the cage, I had to check height on some tubes - 6L6GC variants - and besides Sovtek 5881, the only tubes that seems to fit are TAD 6L6WGC - small bottles - "C" is a little too long...
I will replace all e-caps since it has been on storage for such a long period.
Do you guys have EXP with this set up? It's dead clean inside - no one has been there since it left factory..
9200 schema:
http://www.el34world.com/charts/Schematics/files/marshall/9200_2x100w.pdf

I have used JMP-1 a lot on a studio with metalhead bands but never opened one up..
JMP-1 schema:
http://www.el34world.com/charts/Schematics/files/marshall/jmp_1.pdf

Thanks in advance
Best Regards

Rzenc

[DummyLoad]

what a load of garbage that 9200 is. sorry, but i don't equate a greater parts count to better tone. that thing has to be a nightmare to service. sheesh! sand state current sources? you'd think they were designing a hi-fi and got side-tracked into building a guitar amp.

[rzenc]

what a load of garbage that 9200 is. sorry, but i don't equate a greater parts count to better tone.

Agreed... Less is more

that thing has to be a nightmare to service.

Yeah...tight as hell...

sheesh! sand state current sources? you'd think they were designing a hi-fi and got side-tracked into building a guitar amp.

Had the same feeling when I saw the schematic...They could have used a EF86 instead, at least it would be glass-friendly
Maybe we can come up with some cool mods...I will talk to my friend tomorrow...

Is there any reason why R40 - 56K noted as 1/2W metal oxide - must be metaloxide??

P.S. DL: I 'm still working on the .dwg file... did not forget..

Best Regards
Rzenc

[DummyLoad]

P.S. DL: I 'm still working on the .dwg file... did not forget..

cool! thought you gave up.

Maybe we can come up with some cool mods...

honestly, i wouldn't know where to start... maybe a gut it out and start over...  :-\

Is there any reason why R40 - 56K noted as 1/2W metal oxide - must be metaloxide??

looks like R39 and R40 are 1/2W - metal oxide used in power supply - flame proof.

[rzenc]

P.S. DL: I 'm still working on the .dwg file... did not forget..
cool! thought you gave up.

Not that easy pal!!

About the mods, I will first bring it back to life..them we see...

Thanks for the info about the resistor...

Best Regards
Rzenc