Thursday, 19 June 2014

Ibanez SD9M Sonic Distortion Mod

There are two dual opamps, and one half of the other is completely unused in the original. So i used the remaining half as a buffer for the reference voltage. D1 and D2 are your clipping diodes. Should be easy enough to add a third switch to act as a diode clipping switch.




25 comments:

  1. What is the advantage of buffering vref? Sorry for bein a noob!

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    1. More stable reference voltage. And this configuration is rather pro :)

      I have no idea why they'd use two dual opamps in the original either, as the one half is a signal buffer. One transistor would have been enough to replace the need for another opamp. But. I guess it's one of those things where folks will be selling these used at ebay with a "It has TWO JRC4558 chips in it" -line.

      Nice read on the unused opamp halves: http://encon.fke.utm.my/nikd/latest/sloa067.pdf#page=8
      +m

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    2. Thanks Miro

      The clips of this actually sound pretty badass. I like the mids switch

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    3. No problem mate. I think i want to build one for myself once i got back to my desk. With on-off-off clipping switch :)
      +m

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  2. Hello Miro, even without the clipping switch would you consider this project verified? should it work?

    Thanks.

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    Replies
    1. I haven't built one yet, and as far as i know, no one else hasn't either. So no. I wouldn't call it verified at the moment. Sure, it should work :)
      +m

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    2. Thanks for the answer Miro, we dont have vero boards in our country so i have to draw everything (photoshop) then do the PCB Etching following your projects. Im interesting in this one with the gain and mid switch :)

      Cheers

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  3. Is this buffered bypass?

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    1. The bypass method is separate in 99% of the layouts on this site (basically all layouts unless it's mentioned otherwise) and so you can choose whatever method you prefer, true bypass, buffered or any other method you want. We suggest the true bypass method shown in the Offboard page, but some people prefer buffers and they can do that no problem if they want to.

      The circuit itself does have an input buffer so the signal hits the buffer first before going to the amplifying stages.

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  4. thanks for your clear and helpful planation Mark, i'll go for the true bypass them.

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  5. mirosol iviark hello and help me, I just got B20k pot tone ,any idea to put resistor
    order to be 25k, thanks, sorry my bad english

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    Replies
    1. finaly work fine,. thank for this layout
      :)

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    2. Great to hear it Agung! Cheers!
      +m

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    3. Hay miro all layout in guitar fx layout very cool,but Why is there no layout sanamp GT2?

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    4. Because the circuit is huge :)
      +m

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    5. Yes I know it is huge .. As flanger

      i prefer veroboard, Because vero makes me think. Btw Hey .. I'm waiting for the latest layouts. :-P

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  6. Hi,
    when the volume is full its like the same nivel the clean sound !
    any idEa about change something for have more volume ?
    FRANCK
    BEST REGARDS

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  7. I have made this pedal (is my first one) and it sounds good i like the way it sounds but wen the gains switch is one it has a lot of hum everything in the connection is ok and i have seen every ground point and stills ok the only thing i have to say is that i have proved it with a 12v power supply
    Hope you can help me with that
    Best Regards!!!!

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    Replies
    1. What I've learned over dozens of pedals; check and double-check. And after that, check again :)
      Firstly I'd check the board for solder bridges and bad cuts (believe me, those are the corner stones of many malfuntioning builds) :)
      Then check that the switch works like it should (with a multimeter, ofcourse).
      I can't say how the 12V supply would affect this one, but to rule that out, try using 9V.
      Also, check the Distortion -potentiometer. I had a "budget model" Distortion -potentiometer on my build and the signal barely came through. After I changed it, the pedal came to life. And I must say, this pedal rocks!

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  8. I just built this and one half of IC 1 has 8volts on pin one and 1.5vopts on pin two. I know they are supposed to be relatively similar. Any ideas what might be wrong? Thanks!

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    1. Make sure you have made a clean cut on the board under the IC1 (between pins 1 and 8). That kind of voltages should only be present in the +V -line = both leads of D5 and 100R resistor and pin 8 of both IC's.

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    2. Oooops! Forget about my D5 and 100R nonsense! I had a different layout opened on my screen :D
      But check that cut under IC1, between pin 1 and 8.

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  9. Hi Mirosol, I think there is a small mistake in your layout. According to the schematic at http://aionelectronics.com/wp-content/uploads/2014/06/sd9m-schematic.png, the resistor to the right of the layout, the one connecting to the 470nF cap to the diodes, should be a 2K2, just like the one after, in the signal chain. It is the one tagged as R10 in the schematic, I guess this is why it has ended as a 10K in your layout... ;)
    I have fixed it in my build, and it is working like a charm. :)
    I will now be playing with the clipping diodes... ^^
    Thanks for that layout, I think this pedal sounds awesome! :)
    Cheers

    ReplyDelete