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  1. M

    Cascade Mod for a 50w Plexi clone

    Thanks for the info, I didn't build the amp, but it was a mess when I got it!! Before I cleaned it up some: What exactly is lead dress, and what do i need to fix? Thanks
  2. M

    Cascade Mod for a 50w Plexi clone

    Okay, I might need a little more explanation. The only thing I did different was to unsolder the wire at lug 2 on V1 and tape, then ran a new wire from that lug to the lifted end of the 470k resistor. I just did this so I didn't have to lift the board up to unsolder underneath the 68k resistor...
  3. M

    Cascade Mod for a 50w Plexi clone

    Well that didn't work!! Bright channel squealing when vol turned up, normal channel sounded same. Yuk!!
  4. M

    "Pointer" knobs??

    Should a '77 JMP have them?
  5. M

    "Pointer" knobs??

    Yep, those!!
  6. M

    "Pointer" knobs??

    I guess, the ones like this amp has in pics: http://www.marshallforum.com/lets-talk-vintage/66114-nad-1976-jmp-50w.html
  7. M

    "Pointer" knobs??

    Okay, dumb question: Which models and years of the amps came with the "pointer" knobs, for lack of a better word? I have a '79 JMP with them, but curious as to years and models? Thanks
  8. M

    Cascade Mod for a 50w Plexi clone

    Cool, thanks! I'll give it a try. I also have a PPIMV installed if that makes any difference.
  9. M

    Cascade Mod for a 50w Plexi clone

    Can someone give me the idiots version of the cascade or one-wire mod for this amp? I have searched and can't find much that I can use. Here are a couple got shots for direction. Thanks
  10. M

    Transformers on a '74 Jmp

    Thanks!!
  11. M

    Transformers on a '74 Jmp

    Does this look correct for a '74? Thanks
  12. M

    Marshall 1987T Tremolo '73 in the house!

    Cool, I missed the attenuator! Def sounds good!
  13. M

    1983 jcm800 4210 to el34 question

    Did you see my post on "Getting '79 JMP 2204 to bias in range"? Guessing you have the same issue.
  14. M

    Coverting a JMP 2204 or JCM 2204 to EL34's

    Me too!!
  15. M

    5153 with low output

    Check the impedance good, give it a jiggle while playing. That is how I figured out the one in my 4100 JCM-900 was acting up, same symptoms as you guys have.
  16. M

    My plans for tonight

    My '79 JMP 50w plate voltage is 402v.
  17. M

    79 JMP Low Power Output

    I second the ohm selector, make sure the plug is making good contact. I had the same symptoms happen to my -900 with the slide ohm selector.
  18. M

    My plans for tonight

    Don't do it!! Go buy a cheap -900 that has all that stuff, save the JMP!!
  19. M

    Getting JMP 2204 bias in range

    Yep, its -42.2 to -41.7 on pin 5 of the tubes. Here are the power tubes that are in it.
  20. M

    Getting JMP 2204 bias in range

    I'll check it tomorrow and report back. Did this amp come with EL-34's or 6550's or something similar?

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