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

Please login or register.

Login with username, password and session length
Advanced search  

News:

Need a Schematic? Check the Vault *MP-1 Classic Schematics Just Added!!

Pages: 1 [2]   Go Down

Author Topic: my new mp1 sounds like dudu  (Read 917 times)

0 Members and 1 Guest are viewing this topic.

davidfugler

  • Newbie
  • *
  • Offline Offline
  • Posts: 19
Re: my new mp1 sounds like dudu
« Reply #15 on: Time Format »

although it's much louder, the bass sounds centered at around maybe 400 hz or higher. the treble and presence both sound very narrow. picture a graphic eq with 5k pushed up quite a bit and maybe 6.5 k pushed up the same. that's with both at zero. if you turn either, or both up it just sounds like fingernails on chalkboard. not at all what i hear when i listen to mp1 clips online. does it look stock? or modded?
Logged

MarshallJMP

  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 3787
    • marshalljmpmodshop.net
Re: my new mp1 sounds like dudu
« Reply #16 on: Time Format »

Looks stock to me.
Logged

davidfugler

  • Newbie
  • *
  • Offline Offline
  • Posts: 19
Re: my new mp1 sounds like dudu
« Reply #17 on: Time Format »

any idea where i can get a power switch and input jack?
Logged

rnolan

  • Administrator
  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 4901
Re: my new mp1 sounds like dudu
« Reply #18 on: Time Format »

Looks like a good candidate to do the rear jack mod (and replace both input jacks) http://www.marshalljmpmodshop.net/miscellaneous_parts_and_replacement_tubes.htm.MJMP can probably help you with a power switch also.
Logged
Studio Rig: MP2/MB1 > Eurorack UB2442FX-Pro > TC M-One XL > Behringer Truths (with Truth Sub) / QUAD ESL 63s
Live Rig: MP2/MB1 > Alesis Quadverb > Alesis Midiverb 4 > Yamaha AM802 > B200s/Carvin TS100/DCM200L > ADA Split Stacks/Mesa P112s

MarshallJMP

  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 3787
    • marshalljmpmodshop.net
Re: my new mp1 sounds like dudu
« Reply #19 on: Time Format »

Why do you need a new power switch? is something wrong with it?
Logged

davidfugler

  • Newbie
  • *
  • Offline Offline
  • Posts: 19
Re: my new mp1 sounds like dudu
« Reply #20 on: Time Format »

I have to switch it on 2 or 3 times to get it on, quite often.
Logged

MarshallJMP

  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 3787
    • marshalljmpmodshop.net
Re: my new mp1 sounds like dudu
« Reply #21 on: Time Format »

That's not a switch problem, looks more like a power supply problem.
Logged

davidfugler

  • Newbie
  • *
  • Offline Offline
  • Posts: 19
Re: my new mp1 sounds like dudu
« Reply #22 on: Time Format »

think that could have anything to do with the thin sound? I was thinking of getting your transformer upgrade. what do you suggest I do?
Logged

davidfugler

  • Newbie
  • *
  • Offline Offline
  • Posts: 19
Re: my new mp1 sounds like dudu
« Reply #23 on: Time Format »

if I do the rear switch mod, someone said the earlier models are difficult to change the front jack. If it's a 1988 what do you suggest? My soldering skills are pretty questionable, at best. Also, the far left (input) LED just barely flickers, with both gains at 10. Sorry if I'm a scatterbrain.
Logged

rnolan

  • Administrator
  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 4901
Re: my new mp1 sounds like dudu
« Reply #24 on: Time Format »

Having watched/helped Mike do the rear jack mod it's not the front jack that is difficult as you change it to a normal jack (as used in the later models) rather than the PCB mounted jack socket.  The rear socket is a bit harder as you have to bend things open a bit to get the old one out (IIRC) (which is the normal/easiest/least time consuming way and what Mike did) OR undo all the rear jacks knobs etc to completely disassemble the back plate.  However, once dissembled the rest is easy, so this way takes more time.  If you look at the pic (http://www.marshalljmpmodshop.net/miscellaneous_parts_and_replacement_tubes.htm), the right hand jack (normal style- pre soldered) is the front jack replacement, the other one (black plastic) is for the rear.


Logged
Studio Rig: MP2/MB1 > Eurorack UB2442FX-Pro > TC M-One XL > Behringer Truths (with Truth Sub) / QUAD ESL 63s
Live Rig: MP2/MB1 > Alesis Quadverb > Alesis Midiverb 4 > Yamaha AM802 > B200s/Carvin TS100/DCM200L > ADA Split Stacks/Mesa P112s

Systematic Chaos

  • Administrator
  • Hero Member
  • ******
  • Offline Offline
  • Posts: 656
  • Blood type: Becks Positive
Re: my new mp1 sounds like dudu
« Reply #25 on: Time Format »

think that could have anything to do with the thin sound? I was thinking of getting your transformer upgrade. what do you suggest I do?

Let me suggest a methodical approach here...

I'm with MJMP suspecting something in the PSU being the culprit for the power-up issues. Low and thin gain could be the old front jack and/or Diode D16 as well as some old dried out caps having gone far off specs.

To address all of the above:
- do the Noise Mod
- do the rear jack conversion Mod
- do the Battery Mod

That should get you back on track. Concerning the transformer: some prefer the smooth compressed sound of the original tranny, some prefer the added clarity of the MDRT.
If you get it up and running again with the 3 mods I mentionend you can still decide if you like what you're having or if you wanna add the MDRT.

Soldering is no witchcraft. The hardest/most difficult part soldering-wise of the mods I mentioned above is changing the U4 OpAmp (IMHO).
If you're uncertain you can do it, gather all parts for the mods and take it to an amp repair guy or (if you still have them in your neck of the woods) an old TV repair shop.
It's just swapping some resistors and caps and an OpAmp for newer better spec'd/higher quality parts. Desolder the old parts carefully while paying attention not to lift/burn any traces (less heat on the soldering iron is more!!). Clean everything nice and tidy with desoldering braid and PCB/Solder Flux cleaner, put in the new parts, make sure you get clean solder joints. Clean everything with Solder Flux cleaner again after the soldering job and you're golden.
« Last Edit: Time Format by Systematic Chaos »
Logged
Mesa Boogie MkIVb short head, ADA MP-1 v2, Fractal AxeFX II, Rocktron Velocity 150; Digitech GSP1101, DigiTech 2120Artist, Carvin Tube 100, Yamaha MFC10//
Ibanez RG550RF, Ibanez 540S-LPF DY, Ibanez RGR620TKS, Ibanez RGR620TPS, Ibanez RG550Ltd BK, Ibanez RG7620MSOL, Ibanez RGR465MCA, Ibanez RGR765RCB, Ibanez RG620QMSP, Ibanez RG1420FBHB, Ibanez RGT42MDX, 90s ESP M-II Dlx //
DiMarzio CrunchLab/ToneZone/Gravity Storm/Liquifire/AirNorton/PAF Pro/HfH/ibzUSA F Series pups

davidfugler

  • Newbie
  • *
  • Offline Offline
  • Posts: 19
Re: my new mp1 sounds like dudu
« Reply #26 on: Time Format »

Thankyou. I will do those mods and see what happens. :)
Logged
Pages: 1 [2]   Go Up