Harmonic Jerkulator

Started by estch71, August 04, 2013, 12:53:18 PM

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estch71

I built this last night and, surprisingly enough, it sounds great.  I wanted to add a tone knob or SPST switch for a mid cut to it but wasn't sure on where to add it to the schematic.  Any advice is greatly appreciated. 

Here's the layout:

Are you saying that I put an abnormal brain into a seven and a half foot long, fifty-four inch wide GORILLA?

nocentelli

#1
I'm not sure you could easily get a midscoop just by altering that layout: You need at least a couple of caps and resistors to get a useable mid cut. You could build a tiny daughter board, and connect it between the output cap and the volume pot.

Here's a circuit I've used before, it scoops at about 800hz which is roughly where the Big Muff mid scoop occurs.



Here's a frequency plot for the pot rotation done for me by ~arph at the other place:



As you can see it cuts a fair bit of level, so I'd only use it if the Jerkulator's got plenty of output on tap.
Quote from: kayceesqueeze on the back and never open it up again

estch71

definitely going to build that but, as a newbie, which one is the output cap, the 22uf?  It seems obvious that's the one but, I just wanted to be sure.

Thanks for the advice!
Are you saying that I put an abnormal brain into a seven and a half foot long, fifty-four inch wide GORILLA?

nocentelli

No, the 0.1uF cap that connects to the volume pot.
Quote from: kayceesqueeze on the back and never open it up again

mistahead

I love this circuit for its simple but amazing outcomes, mixing up the trannie pairs can be interesting too.

estch71

It's a nice circuit.  It's almost like an edgy boost but, it goes all the way to 11.

Nocentelli, it it possible to incorporate that daughterboard into a pedal of its own?
Are you saying that I put an abnormal brain into a seven and a half foot long, fifty-four inch wide GORILLA?

nocentelli

You could, but it's quite lossy so if i was building it as a standalone pedal, I'd incorporate a gain recovery stage after it: You might want some sort of buffering or boost before as well. I did a vero layout for a version of this with a mosfet input stage -> mid cut -> gain recovery stage:



Quote from: kayceesqueeze on the back and never open it up again