Growl Stompbox Question

[Inventor]

Hi, I am new to making stompboxes and I have a few questions. 

First, is there such a thing as a "Growl" stompbox that creates the desired growl for bass guitars? 

Second, I am interested in making stompboxes that mount on the guitar, either on the scratchplate, below the bridge, or inline with the cable - is that novel or interesting to anyone? 

Third, am I stoopid to think that I could supplement my meager income by making unique stompboxes, or has it all been done?

Finally, my plan is to make my stompoxes open source so folks can either DIY or just buy from my home business, either way they want.  Is that wise? 

Thanks in advance. 

[MikeH]

1)  Depends what you mean by "growl".
2)  The first EHX as well as Dan Armstrong FX are designed this way
3)  Stoopid is as Stupid does 
4)  Selling kits as well as the finished product?  I think a few builders do it; can't say how successfully

[Inventor]

MikeH, growl is a kind of earthy, gritity sound on top of the bass.  By watching waveforms on my scope it appears to be done with small irregular triangle waves superimposed on top of the bass signal.  For example in (Anestesia) Pulling Teeth, a solo by the Metallica bassist, the waveform is largely sinusoidal from the guitar with triangles on it from the effects.  People accomplish it with guitar selection including certain woods, amp selection and setting, and of course pedals.  I was thinking of making a pedal called "Growler" that makes any guitar growl, for example. 

As to the kitting, I was just planning to make the schematic open source and let someone do their own layout and build if they wanted, as well as sell it at a low price if they preferred to just buy the dang thing.  Sane?  No, I'm not but is the concept sane?  I really believe in DIY, hobbying, and the community spirit of musicians so I want to offer my work as DIY (see the guitar motion sensor project post for an example). 

Stoopid or kewl?  You decide! 

[Steben]

I would go for a sort of enhancer.
split the signal in two.
one dry path with low pass (cut above 1 or 2kHz) (maybe buffer)
one wet path with high pass (cut under 1 or 2kHz), which gets distorted
At the end they mix.

[Inventor]

I would go for a sort of enhancer.
split the signal in two.
one dry path with low pass (cut above 1 or 2kHz) (maybe buffer)
one wet path with high pass (cut under 1 or 2kHz), which gets distorted
At the end they mix.

That sounds good, Steben.  I just did a prototype in software with filtered noise modulating an oscillator and adding that into the original signal.  It worked nicely.  I could generate the filtered noise from the original signal with a BBD delay line set up as a flanger, so that when the input signal dies down so does the growl.  Would make for a nice effect, eh?