ADA Depot - A Forum To Support Users of ADA Amplification Gear

Please login or register.

Login with username, password and session length
Advanced search  

News:

Temp "Time Format" issue Fix in Discussions

Pages: [1] 2 3   Go Down

Author Topic: Mp1 with drop out volume problem..help!  (Read 16640 times)

0 Members and 1 Guest are viewing this topic.

anto84

  • Newbie
  • *
  • Offline Offline
  • Posts: 22

Hi, last week I bought a second hand Mp1 Classic..now I have the chance to buy an original MP1 too at an half of his prce..but there's a problem!
. The seller says the Mp1 "sometimes" has a drop out volume problem. While playin presets volume become low suddenly. He doesn't know what the problem (and the solution) is.. all he knows is that he never changed tubes and the internal battery..

..So my questions:
- It is possible that the dropping volume problem is caused by the very old tubes and/or is maybe the almost dead battery?
- If they're not the problem..what it can be? Is something that can be solved and repaired from an electrician?

Thank you all!!


« Last Edit: Time Format by anto84 »
Logged

tomy

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 340
  • "To loose means trouble, to win pays double"
Re: Mp1 with drop out volume problem..help!
« Reply #1 on: Time Format »

Hi, l'm giving you a quick answer but some expert like MJMP or Rnolan would more abble to solve your problem.

-Yes old tubes can affect your volume, replacing it will definitely helps (if the previous  owner never replaced it , don't even think twice, do it !)
-No the battery is used for internal memory. Your mp1 can run without battery but you have to put back your preset after each reboot
-But  the tubes could not be the only cause of the issue.

So stay tuned for more info
TG
Logged
"As far back as I can remember,  I've always wanted to be a  gangster..."

ARSENAL :
https://fr.audiofanzine.com/membres/885047/products/

MarshallJMP

  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 4702
    • marshalljmpmodshop.net
Re: Mp1 with drop out volume problem..help!
« Reply #2 on: Time Format »

Is it a volume problem or a gain (distortion) problem?
Logged

anto84

  • Newbie
  • *
  • Offline Offline
  • Posts: 22
Re: Mp1 with drop out volume problem..help!
« Reply #3 on: Time Format »

That's the first question I make to the seller. He says seems a volume problem... But I wouldn't be surprise if it was a gain problem that he has confused for a volume one..
He added that the problem that take place only "sometimes"
« Last Edit: Time Format by anto84 »
Logged

MarshallJMP

  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 4702
    • marshalljmpmodshop.net
Re: Mp1 with drop out volume problem..help!
« Reply #4 on: Time Format »

Well ask him,this way we can narrow down the problem.
Logged

rnolan

  • Administrator
  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 5998
Re: Mp1 with drop out volume problem..help!
« Reply #5 on: Time Format »

Hey anto84, while I'm pretty confident that between yourself and more particularly MJMP you could sort out the problem, do you really want to take this journey ?  To answer all the questions we are going to ask you as we attempt to trouble shoot the issue, you really need to have the MP1 at hand, plugged in. So you would need to buy it (unless he gives you a return policy or whatever ?). So what seems a cheap MP1 may cost a bit more, at least $50 for a new set of tubes... These kind of intermittent problems can be hard to sort out, hey it may be an easy fix ?  You may be better off looking out for a MP1 in good nick with no issues, preferably with new(ish) tubes (and better MDRT and noise mod).

Eg The difference between a Volume drop and gain drop will help determine where in the circuit the problem is.

Not to say that MJMP may be able to narrow it down fairly quickly and give you an idea of what you'd be buying...

Anyway happy to help, just thought I'd ask.
Cheers R
« Last Edit: Time Format by rnolan »
Logged
Studio Rig: Stuff; Live Rig: More Stuff; Guitars: A few

MarshallJMP

  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 4702
    • marshalljmpmodshop.net
Re: Mp1 with drop out volume problem..help!
« Reply #6 on: Time Format »

Well a gain problem is usually either the tubes or the input jack.
Logged

rnolan

  • Administrator
  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 5998
Re: Mp1 with drop out volume problem..help!
« Reply #7 on: Time Format »

My thoughts as well, and both relatively easy to fix. Also the input jack is the component that takes the most wear.

So anto84, when the volume drop happens, is the sound (distortion) still the same just suddenly softer, or do you loose all the distortion...
Logged
Studio Rig: Stuff; Live Rig: More Stuff; Guitars: A few

anto84

  • Newbie
  • *
  • Offline Offline
  • Posts: 22
Re: Mp1 with drop out volume problem..help!
« Reply #8 on: Time Format »

Seller say sound is the same just with volume drop..
Logged

rnolan

  • Administrator
  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 5998
Re: Mp1 with drop out volume problem..help!
« Reply #9 on: Time Format »

Ok, that implies the issue is after the tube board/stage, ask if it makes any difference if chorus on/off ? Is he using the FX loop ? (when the drop happens ?), does the headphone out drop as well (when it occurs) (if no it would imply output jacks..??)

input > tubes > eq > FX loop > chorus > output pot > output jacks is kind of the signal flow.

I seem to vaguely remember an issue with the chorus chip sometimes ??? MJMP will know ?.

New output pot and jacks are always a good idea in a MP1 at this age
Logged
Studio Rig: Stuff; Live Rig: More Stuff; Guitars: A few

anto84

  • Newbie
  • *
  • Offline Offline
  • Posts: 22
Re: Mp1 with drop out volume problem..help!
« Reply #10 on: Time Format »

He can't answer to those questions anymore cause he has sell all his musical gear except the mp1 and a rack multieffect,,,guitar and cabinet are gone...

From what you're saying It seems to understand that the prolmem when the volume drop doesn't affect the gain is more serious than a normal gain loss... And here my doubt concerning the cost for it to be repaired...
Logged

rnolan

  • Administrator
  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 5998
Re: Mp1 with drop out volume problem..help!
« Reply #11 on: Time Format »

Well it's probably not just put in new tubes (something you need to do every couple years regardless), it may not be more serious, you could take a chance on it, it may end being a simple fix (eg new output jacks or maybe they just need a good clean ??). Hey if you decide to go for it we're happy to help sort it out. I suspect though your trying to get a take on what may be involved (ie should you buy it, hence my earlier question, do you want to go on this journey ?). And anyway, if it just happens here and there, while you'd want to get that sorted (particularly for live gigging) it doesn't mean you can't use it.
Logged
Studio Rig: Stuff; Live Rig: More Stuff; Guitars: A few

MarshallJMP

  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 4702
    • marshalljmpmodshop.net
Re: Mp1 with drop out volume problem..help!
« Reply #12 on: Time Format »

Volume drops can also caused by a bad V2 tube,other possible culprits are,the front vol pot,output jacks.
Logged

anto84

  • Newbie
  • *
  • Offline Offline
  • Posts: 22
Re: Mp1 with drop out volume problem..help!
« Reply #13 on: Time Format »

Ok, after a phone call with the seller..some news:

He says that, as said earlier, he seems to remember that when the drop volume happens, the gain stays the same and only the volume drop ut. He added that touching a bit the frontal input jack the volume came back to normality...until next drop out

Are those elements enoughfor you to unveil the cause of the problem?
Logged

MarshallJMP

  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 4702
    • marshalljmpmodshop.net
Re: Mp1 with drop out volume problem..help!
« Reply #14 on: Time Format »

does this happen on all 3 voicings?or just on the 2 tube voicings?
Logged
Pages: [1] 2 3   Go Up