Re: Adding bass control

Posted by induction on May 16, 2016; 2:07pm
URL: http://guitar-fx-layouts.238.s1.nabble.com/Adding-bass-control-tp30475p30666.html

The gain pot is a nice feature. It gives you separate control over bass boost and total volume. That way you could use the effect as switchable EQ with or without a volume boost.

However, with respect to the pot-controllable bass control, I'm afraid the Fat Control is just not a good platform for what you are trying to do. There are no resistors in the circuit that can be turned into pots to make a bass cut control. Besides the input and output caps, C4 in the madbean schematic can be reduced to decrease bass. Values between 10n and 100n give reasonable results. You'll get more mileage from the input caps though.

If you want a low cut you can control with a pot, you could put an active high-pass filter in front of this thing. That will let you control the high-pass corner frequency with a pot. But putting a hi-pass filter in front of a bass-boost is like trying to fine-tune the temperature in your house by running the heat and air-conditioning at the same time. It makes a lot more noise and gives you a lot less control than just using the right circuit for the job.

At that point, you may as well build an EQ that does what you want it to do. A 1-band parametric EQ will give you control over the center frequency of the boost (or cut) as well as the amount of boost/cut, and the width of the frequency band. Breadboard one of those and you'll learn plenty about fine-tuning EQ. There are lots of other pedals that would be good platforms for fine-tuning a frequency-dependent booster. The EWS Bass Mid Control looks like it would be a good candidate. And again, if you haven't breadboarded the Blade mid-boost circuit yet, do yourself a favor and try it out. Google parametric eq and active bandpass filter for more ideas.

I'm going to go ahead and strongly suggest you do this sort of thing on the breadboard instead of building a vero and then trying to mod it. I'm sure everybody is getting tired of me harping on this, so I'll just shut up about it now.