MP-1 Gain section

DannyjoeCarter · December 30, 2016, 02:47:59 AM

OK Folks another techie question;
How many stages of gain are in the MP-1 and how much voltage is hitting the two tubes?

I'm figuring the MP-1 is not like the Marshall JMP1 where I believe it's solid state/diodes and gets warmed up a little bit somewhere along the line with a 12AX7? I think the Rocktron Voodoo Valve did the same thing - SS then gets a little tone from a 12AX7 -

Harley Hexxe · December 30, 2016, 03:07:39 AM

Hi DJC,

No, the MP-1 is definitely not like the JMP1. I think there are two gain stages, but MJMP would be the one to answer that question definitively.

DannyjoeCarter · December 30, 2016, 10:41:10 AM

OK thank you Harley, I will wait for MJMP to jump in on this one :)

MarshallJMP · December 30, 2016, 12:23:18 PM

Since each 12ax7 has 2 sections there are 4 gain stages in the MP-1.Same goes for the MP-1 classic and MP-2 (and even the MB-1).

And yes you are right about the JMP-1, solid state with a tube for warmup. One tube for the clean section and one for the distortion section.So no real tube overdrive sounds like in the MP-1.

Harley Hexxe · December 30, 2016, 12:28:44 PM

Quote from: MarshallJMP on December 30, 2016, 12:23:18 PM
Since each 12ax7 has 2 sections there are 4 gain stages in the MP-1.Same goes for the MP-1 classic and MP-2 (and even the MB-1).

And yes you are right about the JMP-1, solid state with a tube for warmup. One tube for the clean section and one for the distortion section.So no real tube overdrive sounds like in the MP-1.

Well that solves the mystery for me too! Thank MJMP

DannyjoeCarter · December 30, 2016, 01:16:48 PM

OK good to know MarshallJMP!
You can actually feel it when you play the MP-1 because there is a give and a breathe to it. I have been playing my best friend's 1.38 for the last two weeks until mine arrive and I remembered the way the MP-1 responded to your picking attack the same way a regular tube amps feels.
The Rocktron Chameleon and the Marshall JMP1 has a very stiff solid state feel which, can sound good at times but when you crank it really loud is when you really hear and feel that something is missing - like the tubes! LOL!

Still a little curious how much voltage flows through those two tubes -

MarshallJMP · December 30, 2016, 02:11:48 PM

The standard high voltage is 190V, with an MDRT you can bump it up to 240V.

DannyjoeCarter · December 31, 2016, 02:04:56 AM

Quote from: MarshallJMP on December 30, 2016, 02:11:48 PM
The standard high voltage is 190V, with an MDRT you can bump it up to 240V.

Wow that's pretty hot - I like that!! I'm going to for through the forum and find a little more about the MDRT and who on here can do it and how much!
Great info Marshall JMP

rnolan · December 31, 2016, 04:28:19 AM

Hey DjC, MJMP gets the MDRTs made, prices are on his site (http://www.marshalljmpmodshop.net/miscellaneous_parts_and_replacement_tubes.htm). It's not a hard mod with minimal soldering, but easy job for any tech. And as I posted before, really opens up the MP1.

Harley Hexxe · December 31, 2016, 04:38:11 AM

Quote from: rnolan on December 31, 2016, 04:28:19 AM
Hey DjC, MJMP gets the MDRTs made, prices are on his site (http://www.marshalljmpmodshop.net/miscellaneous_parts_and_replacement_tubes.htm). It's not a hard mod with minimal soldering, but easy job for any tech. And as I posted before, really opens up the MP1.

That's the popular concensus, but to my ears, it seems to alter the core tone of the MP-1. For better or for worse is subjective to your personal taste, and what you are looking for out of your amp. That's why I haven't jumped on that bandwagon. I'm not sure I would like the change.

rnolan · December 31, 2016, 04:51:58 AM

Hey Harley, again very salient, and I hear what you mean. I think you would like the change but ideally you kind of need one of each. I was gobsmacked after MikeB made the change to his MP-1, the MDRT really opens up the MP-1, but the MP-1 stock has a creamy (almost boxy) sound (kind of warm ??). With MDRT it's allot more articulate.

Harley Hexxe · December 31, 2016, 04:59:50 AM

Quote from: rnolan on December 31, 2016, 04:51:58 AM
Hey Harley, again very salient, and I hear what you mean. I think you would like the change but ideally you kind of need one of each. I was gobsmacked after MikeB made the change to his MP-1, the MDRT really opens up the MP-1, but the MP-1 stock has a creamy (almost boxy) sound (kind of warm ??). With MDRT it's allot more articulate.

So it's not just me who noticed it. That's the thing I like about the original MP-1 it has a warm low end to it. So you lose some of that warmth with the MDRT?

rnolan · December 31, 2016, 05:25:56 AM

Hey Harley, no you are correct, the sound changes, is it for the better or worse (subjective). Hey @MikeB you could chime in here.
I think one of my first comments to Mike when I heard it was wow that's going toward the MP2 and what it can do >:D .

So yeah you loose some of the warmth (but better to say boxyness) of stock.

Harley Hexxe · December 31, 2016, 05:38:02 AM

Okay, I don't want to lose that bottom end. Between the MP-1 and the 3TM, I can cover just about anything the MP-2 can give me but with the MP-1 character. There is a difference there.

Of course, that doesn't mean I'll be letting go of my MP-2's

I have too much invested in the learning curve of those now.

rnolan · December 31, 2016, 05:47:08 AM

I cant speak for the 3TM, maybe in the future >:D ?? But the advantages of the MDRT in stock MP-1 are definitely worth it, it's like lifting off a vale seriously

. That said however, there is something in the stock MP-1 sound that you loose (for me it's kind of a boxy/compressed/mud (but nice warm mud)

) so one of each makes sense.

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MP-1 Gain section