Simple bass distortion.

[Buzz]

Whilst thinkering I thought I'd hack create a simple bass distortion.

Most of you will recognize the bits.



So I started with a Hog's foot, via the schematic at ggg

http://www.generalguitargadgets.com/pdf/ggg_hog_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

I kept the part numbering from that schematic for reference. I omitted C5 and C6 as I figured they were both low pass filters. So now this section is really an LPB2 with an i/o  cap change. I wanted to keep the highs in for the clipping stage.

After the booster I have put an AMZ clipping stage. The last option on this page: http://www.muzique.com/lab/sat2.htm

This clipping option is numbered with a 10 prefix. I chose it because it mixes clean with clipped.

The one cap with a 20 prefix I added as a low pass filter for the clean side of the mix.

I have a gazillion questions. I guess I'll find them out / ask them in the breadboard stage.

All advice appreciated before I start testing. I don't want to be barking up the wrong tree.

[Buzz]

OK... Question #1.

Should I put a high pass filter on the distortion side of the wet / dry AMZ clipper stage? To redfuce any farty sounds?

[GibsonGM]

Hi Buzz,

Looks good so far! 
I'd breadboard it, for starters.  A lot of this is easier to do by hearing it rather than over-analyzing it!

Offhand, I'd say C1 and C2 may want to be smaller, like .1 to .5 uF.   Just to cut down some low end.  Might even need to be smaller than THAT! You can tweek them to taste.

Give it a listen, and then you can play around with a HPF if you feel you need it...

PS - all your resistors can be 1/4 watt (even 1/8W!), you don't need 1/2 watt (the pots will likely be rated at 1/2, that is the norm) - unless you just want to use them, it's your pedal    

[12Bass]

In my own bass distortion experiments, I've found that a high pass filter helps considerably.  However, that also means that the lows have to be added back in after clipping to ensure that the bottom doesn't drop out when engaged. 

Some bass distortion units run a clean sidechain with a low pass filter to keep authority in the bottom end, adding high-passed distorted midrange and up to the clean lows to produce a composite tone with grind and full lows. 

[duck_arse]

as drawn, your C1 will be backwards, or arse-about as the techs say.

[Buzz]

Cheers for the hints guys, off to the breadboard I go.

Well spotted Duck. Oddly that's the way around it is on the GGG schematic. Not too much of a fuss though, I was going to use non-polar box caps for all except the power filter.

Mike, yes all my resistors are quarter watt. If anyone else wants to muck around with this circuit ignore the Wattage and Voltage values displayed. They were just the default values put there by the layout program.

[Buzz]

Some bass distortion units run a clean sidechain with a low pass filter to keep authority in the bottom end, adding high-passed distorted midrange and up to the clean lows to produce a composite tone with grind and full lows. 

Yeah, that's pretty much what I'm trying to achieve here, in a very simplistic way. I'm hoping the AMZ mixer / clipper setup will do the job for me.