eq

[philly]

sorry dont know if this is the right place to ask this question but here goes,
I've built a few different od pedals and its been amazing to be able to do that thanks to all the hard work that goes into this great site , and the thing I've noticed with most of the od's is that putting a boss graphic eq pedal before the od and reducing the 6.4kHz works really well for my ears , so is there any way of building that into the actual pedal ? - I dont really understand enough to look at the eq section of this site and just "add on" a section - any suggestions ?

[Fuzz Prince Of Bel Air]

Add a RC filter on the output.

Specifically a lowpass filter with a 6.4khz cutoff.

[Travis]

A low pass filter would also cut frequencies above 6.4KHz so it would not behave like the graphic EQ

In order to get the same kind of control, you would need to build an active EQ circuit. There is a lot of info online about building EQs with active “gyrator” circuits, as well as some layouts on the main page

http://www.muzique.com/lab/gyrator.htm

[philly]

ah right - thanks - missed that when I was searching earlier - what would the transistor be in that example please ?

[Fuzz Prince Of Bel Air]

Travis wrote

A low pass filter would also cut frequencies above 6.4KHz so it would not behave like the graphic EQ

6.4khz is the last slider on the Boss GE-7 (which is what I assume philly means by "boss graphic eq pedal"), so I assume it cuts around that frequency and above... right?

[induction]

Fuzz Prince Of Bel Air wrote

Add a RC filter on the output.

Specifically a lowpass filter with a 6.4khz cutoff.

You'll want the filter on the input, not the output. You'll also want to make it an active filter or add some make up gain, since passive RC filters are lossy and input amplitude has a strong impact on the response of the od.

To reproduce the current tone exactly, copy the GE-7 circuit and remove the other filters. But really, any active lowpass will probably get you pretty close.