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4-knob Starlit Snow Day + "stock" Bearhug with hidden extras

Started by midwayfair, December 10, 2016, 08:10:23 PM

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midwayfair

I might not be 100% done with the Snow Day, but it won't look any different if I change it:



This is most likely going to a local guitarist, but he needs to test it out first.

I made a couple tiny refinements while building this one, like C8 and C11 can just be 22nF, not 220nF, and D1 (the compression rectifier) can't be a 1n5817 apparently because it's too leaky. (I suggested some fixes in the build thread for anyone who's interested, but the easiest if you're building Brian's stock version is to replace the 5k6 right before the tone control with a 22nF or larger cap. You lose a tiny bit of available cut but it solves the entire issue without having to buy other diodes.)

The bass control is courtesy of Brian's addition of a HPF right before the gain control, R4 and C4. Although Brian's build doc (at the moment) kind of misstates what these are doing (they're cutting 1.5dB below 68nF, whereas the original was just a straight HPF), I'm glad they're there because they're an opportunity to easily add a bass shelf. I used a 1MC and a 1nF, which gives 12dB of control below 318Hz. It's not extreme but it's definitely noticeable. Just not sure I'd really put it on another build if my friend hadn't specifically mentioned wanting a bass control. It's also sort of philosophically weird for the design since it's not like a tweed Deluxe had a bass control, but anyway. The rest is basically stock to my schematic.



The order was for a regular Bearhug, but the customer uses an archtop and a tele with a Charlie Christian pickup. Since archtop + Bearhug is a recipe for distortion, I did some testing and found that a high pass filter on the front end fixed a lot of the issues, like triggering the compression too hard and overdriving the mosfet. I put a -3dB pad at 200Hz (2M2 with a 150pF in parallel) and a -6dB pad at 150Hz (4M7 with 220pF in parallel) on the front of the circuit with little dip switches to simply bypass them. They're just between the switch and the board input.

This gave me some ideas for doing a friend's build, too.

playpunk

Fantastic Jon. Glad to see a build or two from you again.
"my legend grows" - playpunk

warriorpoet

Awesome, Jon! I love how much you continue tweaking your circuits after they go gold.

I'm about to finish up a Flabulanche, and one of your notes has piqued my interest:

So, if I understand you correctly, replace R16 (5k6 resistor) with a 22nF cap? Is that right?
Mzo.FX, Owner

midwayfair

Quote from: warriorpoet on December 11, 2016, 03:24:16 AM
So, if I understand you correctly, replace R16 (5k6 resistor) with a 22nF cap? Is that right?

Yes, this is the easiest way of dealing with the diode leakage if you don't have any 1N60P or BAT85, BAT43 (I think) or another very low Fv, low leakage diode. You want a Fv not much higher than a 1N5817 (measure it on your multimeter) but measuring in Mohms if you measure it on resistance "backwards."

Brian had increased the size of the tone cap, so that resistor is nowhere near as useful as it was in my original anyway. You shouldn't miss having it.

Boba7

So nice, you hadn't posted in a while! The Snow Day is absolutely beautiful, I love it, it's a real piece of art.

Everytime I build a 1590a I think of you. :)

playpunk

EQ options are always good on OD pedals. A little bass goes a long ways.
"my legend grows" - playpunk

jimilee

Quote from: playpunk on December 11, 2016, 02:13:22 PM
A little bass goes a long ways.
Just imagine how much a lot of bass would go!


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Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.