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Fatpants/charge pump questions

Started by HKimball, June 11, 2014, 07:54:02 PM

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HKimball

So, I tried to do my best to copy the fatpants layout seeing as right now they're unavailable.

I used the 3PRR and ran the tip of the input to a dpdt switch - the first side goes into the footswitch/charge pump (for true bypass) and the other side is connected to the "in" (which is in turn connected to the "in" part of the circuit)

Also, I've connected the "sw" portion (that activates the buffer) to the two unused prongs in the 3PRR (middle and bottom all the way left if you're looking at the PDF) so that when I'm on the buffer setting and the footswitch is "off" it should still be buffered. I've since disconnected these so that the buffered setting no longer works, right now. As it turns out, for some reason that I still can't figure out, while all of the other parts of the 3pdt switch work right, those two prongs always share an electrical connection (and because of this I would always be running the buffer and never the effect)

Now, I have a few problems:

- The charge pump which originally worked great now only reads 10.6v (from the +18v out) when plugged into a 9.6v power source. Interestingly enough if I move the black end of my multimeter to the -9v output it reads 12v, which is still way short of 18v
- The "on" setting for the effect only engages the buffer - the "soft" and "body" switches as well as the "fat" control have no noticeable effect. The level control only turns the effect off when turned fully counterclockwise but otherwise has no discernible effect on volume.

I've checked my wiring and it all looks okay (aside from being a complete rat's nest) - I have photos of the board that I'll attach when the email sends (cell phone photos but you can see everything). I don't know if it will help but I sure hope so.

So, in summation,
- Only getting the buffered output even when the effect is engaged (which makes me think the "sw" part is connected somehow but I've double and triple checked and I can't see where the connection would be)
- I'm like 8v shy of where I need to be so even the buffered output is slightly lower volume than bypassed.

I would love any help you guys have to offer but I will continue to work on this and post again if I do ever figure out what I've messed up.

Edit: I'm using the LTR1054 or w/e the one with the 14v input is, and an mpf102/j201 for q1 and q2. I've omitted the portion of the charge pump to the "left" of R11 and "below" R9 if you're looking at the fatpants 2013 PDF.

Double edit: Q1 is seeing voltage but Q2 is not

Triple Edit: (I'll keep updating the first post with my progress so the thread doesn't get bumped to the top) - Cold solder joint on R11, fixed, now Q2 is seeing voltage - at full bias it's ~10v at the (drain? that's what it looks like from the diagrams), and .45v at the source, and 0v at the gate. Again I'm about as green as they get so this is just me working backwards from the diagrams using the internet. There may be some more cold solder joints so I'm going to troubleshoot those.

Still trying to figure out the charge pump and the whole buffered/true bypass switching.