Boost Pedal Changes Tone Slightly When Engaged

[Joel.Chandler]

Hey this is my first post on here so I hope I get it right. I just started building some pedal kits recently. I built the Stratoblaster boost from general guitar gadgets and i love it but when it is engaged it makes my tone a little more bassy...It does still sound really good and does give a great boost but I was wondering if there was a way to possibly make it more transparent. If there are any of the components one the board that i could change out to give it a cleaner/clearer boost.

I have learned a lot by reading posts here and figured that it'd be a good place to ask.
Thanks!

[Mark Hammer]

If you want a cleaner boost, then use a charge pump to increase the supply voltage, or simply use more batteries.  There ARE limits to how much gain can be applied to a signal, using a 9v power source, before you simply run out of voltage swing.

[aziltz]

Hey this is my first post on here so I hope I get it right. I just started building some pedal kits recently. I built the Stratoblaster boost from general guitar gadgets and i love it but when it is engaged it makes my tone a little more bassy...It does still sound really good and does give a great boost but I was wondering if there was a way to possibly make it more transparent. If there are any of the components one the board that i could change out to give it a cleaner/clearer boost.

I have learned a lot by reading posts here and figured that it'd be a good place to ask.
Thanks!

a little help with the lingo might get you the right answer. 

It sounds like the sound is too bassy.  That can be fixed by adjusting the input and/or output capacitors to limit some of the bass content.  Search for some reading, I don't really have any specific suggestions.

People "usually" use clean to describe lack of overdrive/distortion/clipping.  Transparent usually describes the lack of EQ artifacts, like mid hump, bass increase/loss etc.  Its all subjective in the end, but that's generally the gist of things.  If your booster is clipping and you want to get rid of that, then you could do things that Mark mentioned to increase the headroom.

[Mark Hammer]

The boost that the pedal applies is determined by the 50k pot and the 10uf cap it is connected to ground through.  That pair determine where any gain is applied.  If the FET finds a more "efficient" path to ground through the pot and cap, then more gain is applied than would be the case through just the 12k resistor alone.  But where is that gain applied?  That is determined by the specific value of the cap involved.  If you drop the value of the cap by half, the point where the gain is maximally applied goes up by an octave.  So, consider changing the 10uf cap for a 6u8 or 4u7 value, or maybe even smaller if you find there is still too much bass for your tastes.

[aziltz]

The boost that the pedal applies is determined by the 50k pot and the 10uf cap it is connected to ground through.  That pair determine where any gain is applied.  If the FET finds a more "efficient" path to ground through the pot and cap, then more gain is applied than would be the case through just the 12k resistor alone.  But where is that gain applied?  That is determined by the specific value of the cap involved.  If you drop the value of the cap by half, the point where the gain is maximally applied goes up by an octave.  So, consider changing the 10uf cap for a 6u8 or 4u7 value, or maybe even smaller if you find there is still too much bass for your tastes.

that makes a bit more sense here.  I wasn't familiar with the circuit, I was just going by the general rule of input/output caps.  I guess its not always the best solution even if it seems like the easiest.

[Joel.Chandler]

Thank you guys! I will be sure to make sure that all my terminolgy is clearer next time too. Like i said i am very green right now. But all this info helps a ton. I am going to try changing out that cap next time i build it (i already gave it to a buddy of mine that needed one and liked it). Also thank you for the detailed explination, Mark.

[Caferacernoc]

Just decrease the size of the input cap until you get the bass response you are looking for.