This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Monday, July 24, 2017

JHS Twin Twelve V1

Here's the original Twin Twelve from JHS. It's an emulator of the old Silvertone 1484 amp. Like a lot of amp emulators (including their Superbolt) it uses JFETs and an 18v charge pump. The schematic can be found here, and I added the charge pump from JHS's Superbolt. Set the trimmers to around 9v and the adjust as need be. Pots are board mounted as usual and it should fit in a 125B with top mounted jacks nicely.


15 comments:

  1. If I would use a normal 18 volts ac/dc, wich part of circuit i've to remove?

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    1. If you're using an 18v DC supply, you'd remove the MAX1044 chip, the 2, 10uF caps, and replace the 2, 5817 diodes with jumpers.

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  2. Hi.Can i use LT1054 in plece of Max1044 (same pinout)?. Thanks for your brillant work!!

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    1. Yeah that should work. And you're welcome!

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    2. Oh, you'll want to leave pin 1 disconnected with the 1054.

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  3. I have this populated on my bench right now.....and it is not quite working. I think the 10uF closest to Q2 should be connected to the strip side of the other 5817 diode (I think this is what happens in your superbolt layout and what the 1044 data sheet says). As drawn above I think the IC chip heats up and dies pretty quick.

    I think something else is still wrong with the power doubler in at least my build though; I can get a pretty clean low output signal out of the effect without the IC in place (biasing the J201's to 4.5v), but when I insert the chip after moving the 10uF cap as I note above (and rebias the transistors) the sounds stops.

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  4. Yes, same with T-funk, the charge pump section is wrong. Now the charge pump section is working, and try to build the rest

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  5. Done! Except error in the charge pump section its verified. Nice one dude 🤘

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    1. Clarify for me what's wrong with the charge pump. Either I'm having major brain farts or the schematic I used is wrong. haha

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    2. Actually T-Funk spot it first :
      I think the 10uF closest to Q2 should be connected to the strip side of the other 5817 diode (I think this is what happens in your superbolt layout and what the 1044 data sheet says). As drawn above I think the IC chip heats up and dies pretty quick.

      Delete