questions before starting a Boss FA-1FET & a Marshall Guv'nor clones

[FredG]

Hello DIYers,

I'm about to build these 2 projects :
https://tonereport.com/blogs/do-it-yourself/the-edge-of-your-seat-build-your-own-boss-fa-1-fet-amplifier
https://tonereport.com/blogs/do-it-yourself/build-your-own-marshall-the-guvnor

But as I red the comments on the bottom of those pages, I have some doubt (especially about the Guv'nor that seems to not work), so here are my questions :

1/ anybody here already build that exact schematics ? Did it work ? any recommandations about it ?

2/ I build those pedal for my bass. I know I have to raise the input capacitor value to favorise the low frequencies.
But wich one are the input capacitor on those schematics ? And do I have to raise the output capacitor too (and wich one is it) ?
(it was pretty easy to find the input capacitor on my first project, a very simple bass fuzz... but here it's only my second project and I'm confused)

Thank you very much for any advice and help !

[pokus]

Hey,
I've already built an Guv'nor but not to that exact same layout. Why do you think it shouldn't work?

Increasing the input cap(the 10nF one) shouldn't be more suitable for bass, cause the cutoff frequency is already about 7 Hz, which isn't in the audible spectrum at all.

[FredG]

Thank you for this answer Pokus

Hey,
I've already built an Guv'nor but not to that exact same layout. Why do you think it shouldn't work?

Because of the 3 comments below the article : 2 people build it 2 time and it didn't work. One of them give this link instead :
http://tagboardeffects.blogspot.com.br/2012/12/marshall-guvnor.html

Wich is your layout ? Do you have a link ?

Increasing the input cap(the 10nF one) shouldn't be more suitable for bass, cause the cutoff frequency is already about 7 Hz, which isn't in the audible spectrum at all.

Sorry, I'm a noob. Do you mean that this pedal doesn't really suit for a bass ? Or that the capacitor is already good for both guitar and bass and doesn't need any change ?
Same for the MosFet pedal ?

Thank's a lot.

[roseblood11]

You should learn the math of high pass and low pass filters - and then use an online calculator.
The other interesting part is the tonestack of the Guv'nor. You might want to change the center frequencies. The "Duncan Tonestack Calculator" is very helpful for that.

If you don't trust the pcb layout, you could use vero board, I have a verified layout at the musikding.de gallery (link is in the signature)

[roseblood11]

... and maybe you want to change the frequency response of the fa-1 tonestack as well. It's called "baxandall". I guess TSC can simulate that, too.

[roseblood11]

[pokus]

Just wanted to say that changing the input cap doesn't make the pedal more suitable for bass. But i also wouldn't say that it is or isn't suitable for bass at all. It depends on your taste of sound.
I've connected my bass to it and quite like how it sounds although I'm no real bass player and think it sounds better with a guitar through it.
But there is something you could try to boost some lower frequencies.
The R-C filter(2.2k and 100nF) in the feedback loop of the first opamp stage defines how much of the lows are amplified.
So you can increase the value of the cap to amplify more lower frequencies. The cutoff here is at 720 Hz, so for example a 150nF one gives a cutoff freq. of 482 Hz. Just play around with the value of the cap and see what you like.


The layout I used is this one: http://tagboardeffects.blogspot.com/2012/12/marshall-guvnor.html
The capacitor I was talking about here is the first 100nF one from the left.

[roseblood11]

The problem with all distorted bass sounds is that you loose definition, it so "muddy".
The better way would be to split the signal and then only distort the higher frequencies. The clean signal should be shaped by an adjustable low pass filter

[FredG]

Thank you very much guys for your advices. Very useful !

Time to learn and experiment... 

[roseblood11]

http://moosapotamus.net/paralooper.html

http://tagboardeffects.blogspot.com/2010/07/guitar-and-bass-paralooper.html?m=1