Thursday, 24 May 2018

Rostex Turbo Metal

I've heard that in 1991 former Lell engineer went on to form a new company called Rostex. At least that's the rumor and i have no other information about the brand or the pedal. You know anything about these (or have a demo clip/video), please do post it in the comment section.

For the layout, in addition to adding series polarity protection and input pulldown, i subbed the output buffer FET to common 2N7000 pinout.

4-knob version:
And the  3-knobbed version:

(Edit 25.5.2018 23:31: fixed a fault with low wiring and added the 3-knob layout
Edit 29.5.2018 20:35: Fixed 3-knob layout that had a misplaced cut on board image)

14 comments:

  1. thanks Miro!

    KP303B is a N-ch Jfet.

    Datasheet link

    And I've seen another version with 3 knobs.

    ReplyDelete
    Replies
    1. For the FET, as it's only an output buffer, i personally see that as a waste of JFET :) - and thus, the 2N7000 would perform the same. As would basically any n-channel FET or MOSFET. One can use what they want. Just mind the pinout.

      I've seen the 3-knobbed version as well. For the floater schematic, that seems to be exactly the same circuit. Except for the Low control fixed on maximum setting.

      I do find these russian circuits interesting as they rarely are just clones of the western designs. With an open mind and one could possible tweak many of those to perfection.
      +m

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    2. I'll see the 3-knob schematic in the evening and possibly tweak the layout accordingly for another version.
      +m

      Delete
  2. there seems to be a mistake with the low knob, according to the schematic low 1-2 should be switched with low 3 and a 4k7 resistor should be added between the new low 3 to ground

    ReplyDelete
    Replies
    1. Thanks for noticing! My bad. Now fixed.
      +m

      Delete
  3. Cheers for this! Love these mystery builds. Just cut my board to size...

    ReplyDelete
  4. Let me know if I'm crazy here... I'm populating the 3 knob version and I think there may be a stray cut in the wrong place on the bottom row on the non-component image? I'm guessing that the correct cut should be 6 holes from the left of the board, instead of 4?

    ReplyDelete
    Replies
    1. I think you're right.
      I guess the two non-component sides of the version layout have been confused.

      Delete
    2. Nowh fuck :) I'll fix them asap... Sorry. been of from doing layout for a while and that's what i get..
      +m

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    3. Fixed. *Should* be ok now.
      +m

      Delete
  5. This comment has been removed by the author.

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  6. This forum thread has some photos of this and a YouTube demo, not of this, but of a Rostex Delay: http://guitar-gear.ru/forum/topic/4570-%D0%B3%D0%B8%D1%82%D0%B0%D1%80%D0%BD%D1%8B%D0%B5-%D0%BF%D0%B5%D0%B4%D0%B0%D0%BB%D1%8C%D0%BA%D0%B8-rostex/

    There's also a schematic on there for a Rostex Turbo Overdrive:

    http://guitar-gear.ru/forum/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=42117

    ReplyDelete
  7. A couple more schematics on this Soviet Guitars thread, including a Rostex Distortion and an Anta Fuzz: http://sovietguitars.com/e107_plugins/forum/forum_viewtopic.php?103421.150

    ReplyDelete
    Replies
    1. Nice! Thanks Luke!

      Do note that the Distortion is pretty much 1:1 with the Turbo Metal.
      +m

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