cap replacements 'good for bass'

[Mgt280y]

Good evening,
I have built the tayda guv'nor and really pleased with the results the tone is great and drive has a nice range.
Unfortunatly there isnt a schematic with these boards but

If i wanted to make this circuit if possible better suited for bass how would i go about it? is it just the input/output caps or is there more to it than that at the min i dont have a good enough understanding of how values affect things.

[GibsonGM]

Hi Dan,

For bass, I might consider doubling the value of the input cap (from 10n to 22n, or even more), and the cap at the 2nd opamp stage output, from 220n to 470n or more.   You would have to do this by ear.

Now, the guvnor also has a tone stack, and to use it for bass you probably have to tweak THOSE caps as well.  Get hold of a schematic, and you'll have to correlate that to the Tayda  board, of course.   

[antonis]

at the min i dont have a good enough understanding of how values affect things.

I've noticed that Sir Mike overcame this point (he's notorious for his laziness.. ) so let's take it easy..

From signal point of view, a series cap with a shunt resistor create a High Pass filter which cuts(*) every frequency below it's own specific "point" which is determined from the 1/2πRC formula - where π=3.14, R in Ohms & C in Farads..

(*) It actually attenuates signal's frequency at a rate which is determined by curve line's slope & filter's order - but let them be for the time present..

Obviously, a series resistor with a shunt cap create a Low Pass filter with the exactly opposite behavior..
(If you combine them you'll create a Band Pass filter and if you "seperate" them you'll create a Band Reject one..)

Sir Mike proposed you to double cap values at the base of doubling them you halve the cut-off frequency - so, if we presume (didn't made the actual math calculations) that the filters were made on the base of, say, 80Hz cut-off you'll lower them to 40Hz..

For Tonestack tweaking is a bit more complicated because of the interaction between the Bass, Mid & Treble arrangements but you may use the above formula as a starting point.. 

[GibsonGM]

I left that for you, Antonis!  You know I get busy and have things I must hurry to do, ha ha!

1) The OP needs a schematic of the Guvnor   http://www.generalguitargadgets.com/pdf/ggg_mgv_sc_guv.pdf

Look at C5 and C9

2) You can start where I suggested, by doubling the cap values and then halving the corner frequencies...but as I said, that will then require you to move from that position by ear, because that isn't a guarantee that it will sound GOOD.  It could distort and require further adjustment elsewhere, who knows until you try it?    Would COULD do the same to the resistor in the filter, but making resistors bigger increases NOISE, which is not a good idea - we quite often with to scale the resistances down, in fact! 

3) We can use 1/2piRC to determine where the cutoff of our filter lies....I like to use 1/ 6.28 * R in MEGS * C in Microfarads.   This avoids the very big number problem, or having to use real scientific notation.

4) Now someone has to work back from the output to find C9, and track the input to C5 on the tayda board.  So, Dan, are you ok with tracing back to those caps?  Perhaps tayda numbered them or something?  1 step at a time.

[Mgt280y]

Wow that's a lot of numbers lol
I have requested the guv'nor from the board manufacturer so at least I can see what's going on where I'll take a look and see if I can identify the caps/resistors
Thanks for the replies

[duck_arse]

at the min i dont have a good enough understanding of how values affect things.

I've noticed that Sir Mike overcame this point (he's notorious for his laziness.. ) so let's take it easy..

[aside] I've heard he didn't even attend his own knighthood ceremony.[/aside]

[GibsonGM]

at the min i dont have a good enough understanding of how values affect things.

I've noticed that Sir Mike overcame this point (he's notorious for his laziness.. ) so let's take it easy..

[aside] I've heard he didn't even attend his own knighthood ceremony.[/aside]

Far better things to do than wear stuffy suits and sit still for long periods of time 

[antonis]

@ Mgt280y: Stay focused on caps and resistors and get away of tragic advices from blue-blooded and down-under guys.. 

[nonoxxx]

Personaly , I would replace all the 0.22 uF coupling caps to 1 uf, and also check the gain stage , R1 and C1 make a high pass filter that determine the bass rollof in this case all frequency above 723 herz will be boosted  .You can try chaging C1 to 1uf and you will get a lot of lows ( 72herz )
Take care if you are changing the value of R1 it will affect the gain of the non inverting opamp. So if you want to boost lows under 72 herz I can suggest you to , for an example of 53 herz :

change R1 to 3k,  C1 to 1 uf and add a 35k resistance in serial to the 100 k gain pot .

And for C5 follow what GibsonGm said ^^

It' really theorical , you will have to test and let your ears decide ^^ you can socket most of the parts and test

[antonis]

To discourage you more  , for further bass mods on circuits, EVERY neighbor cap & resistor create some kind of filter so you have to alter all of these which are involved on signal path....

i.e. it's useless to keep a HPF of 1k5 Hz rolloff freq after a HPF of 750 Hz.. - I know it's more than obvious but some guys tend to use up the mods only on In-Out components... 

[Mgt280y]

Update Tayda say the board manufacturer doesn't supply the schematic so I'll have to trace a blank pcb when it arrives.

[GibsonGM]

Update Tayda say the board manufacturer doesn't supply the schematic so I'll have to trace a blank pcb when it arrives.

Why not grab the schematic off the internet, get a piece of perfboard, and make your own from scratch?  Leave this one for guitar.  Your choice.  They don't even NEED to have a tone stack, if that is bothering you!  Mine has a simple tone control just to cut shrillness out, and it is fine...I do my EQ with an equalizer later.     All the Guv'nor really is, is 2 gain stages with LED clippers. 

Easy to make the body of it, up to the clippers, and then breadboard the tone stack portion so you can change parts to your heart's content.  Just guessing at caps might be OK, but you likely will want to dial their values in a little bit more as you play. 

Just a suggestion, that is how I do things like this to make them custom, your way may end up being different.  Get the building blocks set up, make them permanent, then set up the 'peripherals' like the tone stack, and finalize that after.