I'll get some pics up soon, but this is a criminally underrated pedal. I etched a PCB using the layout from https://effectslayouts.blogspot.com/2018/03/zvex-59-sound.html, which does not include the SHO boost.
I did also make the following modifications:
The toggle switch for the mids basically makes it an OD/distortion switch. In the stock setting (470pF), it's a good overdrive; definitely more 'vintage American' with SOME midrange to it. The gain range from 10 o'clock to noon is clean-ish, and can get into distortion from 1 o'clock to max on drive control. With that drive all the way up, it's a LITTLE looser/borderline fuzzy.
But, flipping that toggle switch for the mid boost is really where it's at. It is one of the best 'vintage Marshall' sounds I've built. Dare I say it does what I wanted that Brown Betty (Dirty Shirley OD) to do: low-to-medium-to-med-high-gain 'kerrang' in a box, with non-flabby bass and useable treble. The '59 Sound (albeit modified) does it in a smaller/simpler package. It covers a lot of ground and I'm still floored by it.
I'll likely check out the Box of Rock next.
I did also make the following modifications:
- Replaced the 470K resistor under Q2 with a 1M trimpot - this allows for the dialing down the low-end.
- Replaced the 470pF cap with a DPDT toggle switch to switch between 470pF and the addition of a 1n cap in parallel. Adding that cap turns it into a midrange + gain boost.
- Removed the 2.2nF cap under the 10K resistor under the vol pads. This is my tried-and-true method for adjusting the overall high-end in a circuit that tacks on that LPF at the end. This is purely preference, but I feel it needs it.
The toggle switch for the mids basically makes it an OD/distortion switch. In the stock setting (470pF), it's a good overdrive; definitely more 'vintage American' with SOME midrange to it. The gain range from 10 o'clock to noon is clean-ish, and can get into distortion from 1 o'clock to max on drive control. With that drive all the way up, it's a LITTLE looser/borderline fuzzy.
But, flipping that toggle switch for the mid boost is really where it's at. It is one of the best 'vintage Marshall' sounds I've built. Dare I say it does what I wanted that Brown Betty (Dirty Shirley OD) to do: low-to-medium-to-med-high-gain 'kerrang' in a box, with non-flabby bass and useable treble. The '59 Sound (albeit modified) does it in a smaller/simpler package. It covers a lot of ground and I'm still floored by it.
I'll likely check out the Box of Rock next.