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Boss Metal Zone MT-2 Help Needed to fix.
Hi, wonder if someone can help me with this pedal that is not working correctly.
When hooked up between the guitar and amp, with no other pedals between; with the battery (New) or a 9vdc (Tip negative) 300ma power supply. In bypass sounds pass right through to clean channel on amp. Step on pedal, red led lights, same sound comes through on amp. Now the strange thing is, when the level control is at 12 o'clock sound is at the correct level. If I turn from 12 down towards 9 o'clock the level drops lower. This also happens when I turn the level up from 12 towards 3 o'clock. Odd eh?
There is absolutely no distortion or any tone difference when any of the eq knobs are turned or the Distortion knob.
I've opened up the pedal and everything looks and smells brand new. No solder bridges, burn marks, overheated IC's or Transistors or Fet's.
I have the schematic for it and have checked all the components to it, and maybe someone can help here; is the following right?
All 4 Fet's seem correct (1 - 2sk184 at Q11 and 3 - 2sk118 at Q2,Q3,Q9)
I have 5 - Transistors 2sc3378 (As shown on schematic, Q1,Q4,Q7,Q8, Q10)
But the other 2 are 2sc2458 (Schematic shows other transistors as 2sc945 for Q5, Q6)
The IC's I have are NJM 14558L for IC's 1, 2, and 4.
IC 3 is NJM 4558LD Is this correct? or did Boss put the wrong IC into posistion 3?
The unit looks and smells brand new with no signs of use or abuse. It came from a music store that was going out of business, so I have no history on it. Maybe it never ever worked. I'd sure like to fix it if I can. I can solder and have built my own pedals and amps etc before.
Any help would be greatly appreciated by this old rocker.
Thanks .
John (61 year young, disabled Rocker)
When hooked up between the guitar and amp, with no other pedals between; with the battery (New) or a 9vdc (Tip negative) 300ma power supply. In bypass sounds pass right through to clean channel on amp. Step on pedal, red led lights, same sound comes through on amp. Now the strange thing is, when the level control is at 12 o'clock sound is at the correct level. If I turn from 12 down towards 9 o'clock the level drops lower. This also happens when I turn the level up from 12 towards 3 o'clock. Odd eh?
There is absolutely no distortion or any tone difference when any of the eq knobs are turned or the Distortion knob.
I've opened up the pedal and everything looks and smells brand new. No solder bridges, burn marks, overheated IC's or Transistors or Fet's.
I have the schematic for it and have checked all the components to it, and maybe someone can help here; is the following right?
All 4 Fet's seem correct (1 - 2sk184 at Q11 and 3 - 2sk118 at Q2,Q3,Q9)
I have 5 - Transistors 2sc3378 (As shown on schematic, Q1,Q4,Q7,Q8, Q10)
But the other 2 are 2sc2458 (Schematic shows other transistors as 2sc945 for Q5, Q6)
The IC's I have are NJM 14558L for IC's 1, 2, and 4.
IC 3 is NJM 4558LD Is this correct? or did Boss put the wrong IC into posistion 3?
The unit looks and smells brand new with no signs of use or abuse. It came from a music store that was going out of business, so I have no history on it. Maybe it never ever worked. I'd sure like to fix it if I can. I can solder and have built my own pedals and amps etc before.
Any help would be greatly appreciated by this old rocker.
Thanks .
John (61 year young, disabled Rocker)
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