Sunday, 13 June 2021

Analog Man King of Tone

 This one is basically two OD circuits in one enclosure so I went with two separate board for the option to only have one in a smaller enclosure. The only differencies between the two channels is the value of the gain limiting resistor at the gain control, the hard clipping diodes and possibly the op amp (the one in the high gain channel was sanded off...).

The layout is based on a schematic avaiable at FSB.

 

Regular channel

 
High gain channel
 


 

 


23 comments:

  1. Here I go...

    About the misterious OpAmp, I´ll put NJM2068DD on both and forget about it.

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  2. For what it’s worth , I have stumbled across a pic on the web that appears to be an original that shows both ICs being JRC4580D.

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  4. You can tag it. Works nicely, sounds almost the same as my other KoT (Mark's layout). With the 2068DD has a litle more bite and dirt (but not something we can brag about)... I tried both. As to the diodes, and I tried a lot, maybe I´m kind of daf but I still not notice any special diferences with dipswich (or togle switch, by the way) on, off, or out. I suspect it is something like king's new clothes.
    So, great work, dude. Keep on rocking!

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    1. Dragao strikes again! Thanks man, tagged it.

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  5. fuzzhead... would you consider? https://www.pedalpcb.com/docs/GeneralTso.pdf

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    1. Yes, it is on the list. But having a hard time to draw and build stuff at the moment.:-/ Hopefully things settle down in a couple of weeks.

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  6. So putting these 1k/100k on a dpdt should do the trick to switch between the 2 channels right ?

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    1. yes, you can do that or use 1k with a 200k Drive pot.

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  7. Hello,
    Sorry to hijack the thread, but is there any chance to feature the mighty Ibanez Renometer?
    It's an awesome eq/booster sounding like a wah.
    Schematics can be found here :
    https://www.dirk-hendrik.com/temp/ibanez_renometer.pdf
    https://mirosol.kapsi.fi/2013/08/ibanez-no-95-renometer/
    https://www.freestompboxes.org/viewtopic.php?t=24587
    https://www.diystompboxes.com/smfforum/index.php?topic=121066.0
    Thank you :)

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    1. Wow, never heard of that one! Looks very cool and is something I would like to build myself.
      But inductors comes in various shapes and sizes. I'm no expert when it comes to inductors but I guess those circular black inductors from Bourns or Murata is preffered over those from Tayda that looks like large resistors?

      And an onboard charge pump for the 9v/-9v operation will be added.

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    2. I have a vintage one (which is now broken for whatever reason), and I used to love it a lot.
      This thing is insanely loud, and it sounds like no other, thanks to the inductors making it sound somewhat like a multiband wah. It carries a bag of character!

      About the inductors, I couldn't tell for sure. What I know is that it's quite difficult to source the bigger one, but I think that we might be able to use a more common value if we adjust one resistor accordingly.

      I have added a chargepump on mine, and it used to work fine (until the PCB and other parts start to show their age and get faulty).

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    3. And done!
      https://dirtboxlayouts.blogspot.com/2021/06/ibanez-no-95-renometer.html

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  8. Just finished this one. Sounds great! Lower output on the drive side when compared to the original, but other than that I think I prefer it!

    https://i.imgur.com/vL6pI7q.jpg

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  9. Regarding the lower output on the high gain side, why would that be? I used the same IC’s and there’s only one resistor change between the two. Ok, just noticed I missed the 100pf on the HG side. Could that be it?

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    1. I'm afraid you have a problem in the high gain side, that only resistor change shouldn't drop the volume at all. I would start with compare the voltages for both ICs.

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    2. I just checked. Pin 3 on the HG side is showing 7v, whereas on the other side its 4.5. All other pins are 10% either way the same between both sides.

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    3. Yes, pin 3 seem to be the culprit. Somehow you got voltage leaking into row K. Luckily, you got another fully working board so you easily can compare if you have any misplaced compotonents, links or cuts. But I suspect that it could be a solder bridge.

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    4. Yeah, that makes sense. Will get back to it later. I did have a quick look and couldn’t see anything, but I think I’ve gone blind to it now so I need a break.
      Cheers
      Ben

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  11. Hi Fuzzhead, you have great layout but I have question that you put 100K resistor between drive 2 and drive 3. I try to check every KOT schematics out there but never found any 100k resistor. What is the purpose of that resistor or maybe I can just ignore one?

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    1. Thanks for noticing. It was a leftover resistor that I forgot to remove. Updated both layouts.

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    2. Yes, thank you for your exellent layout

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