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Sunday, 16 June 2013

Arion MMP-1 Metal Plus

Here's something cool. The design reminds me of something else a lot - i think some of you may want to take the diodes on a switch with red 3mm LEDs :)
Original unit has NEC C157C metal can IC in it, but NEC's own cross reference guide says that this particular IC has been obsolete since around 1975 and it's exactly the same IC as LM301AN, a PDIP-8 chip that is still quite a standard. Original output buffer is marked as 536 in the schematic, so i guess that would be 2SC536 or 2SC5368. Nevertheless, it's still just an output buffer, so i used your average everyday pinout. This way you could use something like 2N3904 or 2N5088 in it's place.

Very little info available. Other than one near mint unit was apparently sold for $250 couple of years ago...

Now verified. I swapped 68p for 470p to tame oscillation, and there were couple slight issues (one cap was typoed to 330n instead of 33n, tone was in reverse, pot tapers felt wrong as those are not stated in the schematic). All those are now fixed. This is in fact very nice Rat alternative. I also used 1N4007s for clippers. Recommended build.



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7 comments:

  1. mirosol15 September 2013 at 13:56

    Built this today and it rocks. Rat-like, but better to my ears. Used 470p for 68p as that tamed the oscillation i got. Also 10p for high bypass instead of 6p. I used 1N4001s for clippers.
    Really nice.
    +m

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    Replies
    1. Unknown20 October 2013 at 10:56

      Mirosol, While I was building the DOD studio pre-amp, I had this in the pipeline too. Just finished it today and it is doind the same thing as the DOD. The only thing common to both is that they both dont have switches in the build. Should this make a difference ? I didnt think so?. However my last successful build before the DOD and Arion was the Colorsound overdriver and if memory serves it had a problem which went away when I hooked it up to a switch. Im waiting on switches atm so cant test the theory till they arrive. Jim

      Delete
    2. mirosol20 October 2013 at 14:07

      Hmmm.. I think you have something fundamentally wrong with your test setup.
      +m

      Delete
  2. Unknown22 December 2014 at 21:40

    I'm planning to build this thing. I don't understand the last cut (from left to right) on the fourth row (from down to up). But I think it doesn't hurt anybody.

    Should it be nice to add some germanium diodes to the clipping switch instead of the LEDs for a fuzzier sound?

    Thanks a lot!

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    Replies
    1. mirosol22 December 2014 at 21:51

      The cut doesn't do anything and it's just a leftover from tweaking the layout.

      LEDs/Si signal diodes should be a better idea. Ge diodes tend to drop the level more than other types, so those may sound too quiet in comparison to Si or LED type diodes. Yellow LEDs should be fuzzy enough.
      +m

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    2. Unknown20 January 2015 at 18:32

      Hey Miro! It's built and it rocks.
      I don't have yellow LEDs so I tried the Ge diodes instead. It's great on both modes: Si and Ge.
      I used a on-off-on switch (like the ROG) but I find the "no clipping diodes" mode unusable, so I probably will swap it with an On-On.
      I've compared it with a DS-1 and I think both usable modes have enough volume.
      First pedal that I built (I've biult maybe ten) that I'm completely sure I want to box.
      The only "weird" thing about this pedal it's that it "losts" some treble with gain at maximum. It happens on both modes. It doesn't literally losts it, it's like in medium to low gain settings the EQ pot have to be in the middle, but with gain at maximum I have to max it. Anyway it rocks.
      Thanks!

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    3. Unknown20 January 2015 at 18:45

      I've just saw the pedal's photo you pasted on the post. It has the EQ pot almost maxed. My amp is a little dark and the DS-1 is a little bright. So I think it's Ok. I'm too used to the DS'1 Tone pot which has to be ALWAYS in less than 10 o'clock to work as an usable distortion!

      Thanks again

      Delete