PPIMV Types

Discussion in 'Marshall Amps' started by matttornado, Aug 11, 2021.

  1. matttornado

    matttornado Well-Known Member

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    Hey all. I just recently saw someone mention the Rich Mod in another thread. That's the only type of master I have not yet tried with my 1959. I guess it's the hardest to implement with the PCB. My amp is a 74 Superlead.

    Does it sound better than the Lar Mar type? The Lar Mar in my amp works OK but doesn't really sound that great until it's turned up too loud & to the point were the Presence control starts to function.

    I was thinking of trying the Rich Mod one these days when I get bored and feel like tinkering.

    What do you guys say?

    I also have an attenuator so sometimes I use that along with the master.
     
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  2. neikeel

    neikeel Well-Known Member

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    The ‘Rich Mod’ is not dissimilar from the Lar-Mar. It uses a dual 500k pot. To implement it neatly you need a x3 lug stand off and shielded wire. The stand off bolts to the board between the 220k grid leaks so that you can desolder the output couplers and flick them up onto the stand off lug.
    You still have decreased Presence functionality. It does add a little distortion to the amp itself. I ran one on a 76 1987 for at least 3 years as my gigging amp and was very happy with it.
     
  3. matttornado

    matttornado Well-Known Member

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    Very cool thanks for the reply! I do remember seeing some pics using the stand off lugs. I think I have one lying around somewhere.
     
  4. Emiel

    Emiel Member

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    No experience with the Lar-Mar, but apparently the key is to use a PEC military spec dual pot as it has very evenly matched sides, which is often not the case with Alpha or CTS dual pots. This is properly why it works so well on lower volumes, and why I don't feel the need for an attenuator or an expensive reamping device :)
     
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  5. matttornado

    matttornado Well-Known Member

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    so you use the Rich Mod?
     
  6. neikeel

    neikeel Well-Known Member

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    I know that George at Metro always used that version. No extra blocking caps required.
     
  7. Emiel

    Emiel Member

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    Yes, I do. Works great.

    Have a look/listen yourself:

     
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  8. Sg-ocaster

    Sg-ocaster Well-Known Member

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    Probably giving you no real info here but. I did some recording on a 1973 1959 with a Rich Mod master volume and it sounded Damn good.....course I had it at ripping volume too(could feel it moving air standing infront of it dialing it up)
     
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  9. matttornado

    matttornado Well-Known Member

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    I saw that a few years ago very cool. Man that Metro forum he had used to [email protected]#!
     
  10. matttornado

    matttornado Well-Known Member

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    thanks for sharing that!!!
     
  11. Emiel

    Emiel Member

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    Honestly, I would suggest finding a decent tech and discuss the possibility to add such a PPIMV on a circuitboard Marshall. You can use one of the speaker outputs so that saves drilling in the amp chassis. Make sure you get the military spec PEC dual 500K pot. Installing it would be easy for anyone who does a decent soldering.
     
    Last edited: Aug 12, 2021
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  12. matttornado

    matttornado Well-Known Member

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    Thanks for suggestion but I been my own amp tech now for 15 years and installed masters many times in my amp, done all repairs and maintenance. I could do it easily as I am a certified electronic tech. & do solder training at a manufacturing facility. I never said I couldn't do it.
    Like I said in the OP "That's the only type of master I have not yet tried with my 1959." I just mentioned the PCB makes it a little more difficult. Sorry for the confusion.:D
     
  13. GIBSON67

    GIBSON67 Well-Known Member

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    I've not used the Rich PPIMV, but I have the Lar/Mar and prePIMV like all 2204's and
    frankly I never use the Lar/Mar as you stated because of losing the Presence control.

    It was the same way when I had a 2203 with two MV's, never used the PostPIMV much. I thought this was a Rich Mod MV but it is different.
    It sounded really good but still no Presence control so I never used it much.

    upload_2021-8-12_8-46-1.jpeg
     
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  14. AlvisX

    AlvisX Garage Guerrilla Gold Supporting Member

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    They really sound about the same to me .....of course, Im no audiophile , I just play 'em
    Everybody bitches about the PPIMV doesn't sound good until you turn it up ......whatever......no amp sounds good til you get it n the sweet spot . PPIMV moves the sweet spot over just a hair , so you MIGHT get invited back to play the same place twice ......

    Maybe .....just maybe the Lar Mar has a little better taper up and down the dial ....but as mentioned before , that may depend on the quality of the pot
     
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  15. matttornado

    matttornado Well-Known Member

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    Thanks for your input! interesting.
     
  16. Sg-ocaster

    Sg-ocaster Well-Known Member

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    WAIT!!!?!?!?!??......that actually happens???:hmm: :drool:
     

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