Guvernator - More Cowbell! No, I mean more Bass

[Spiff4565]

I assembled a Guvenator recently and over all I am very happy with it.

I'm building another one and rather than PCB mounted pots I'm going to fly leads to the solder lugs.

The reason I'm doing this with the pots is because I want the controls laid out like you would find on a Marshall amp panel, Bass, Mid, Treble, gain and volume. The PCB pots put the order of tone controls Treble, Mid and Bass.

Which brings me to my query. The bass on this pedal is a bit anemic, IMHO. Want I am looking for is essentially a bass boost.is this possible by just changing out passive components or would such a modification require circuit/component wizardry? To be clear I am not looking to change the range of frequencies, I am looking for a way to accentuate the frequencies currently controlled by the Bass control.

I've played any number of amps that employed a bass boost and it is this effect I would like to integrate into the Guvenator.

If there is an existing PCB that sounds similar to the Guvenator that already has this feature or characteristic already baked into the design, please let me know which board to look at.

 

[hamerfan]

The easiest way to change the bass of a pedal is vary the input cap (c1: 9n6) or make it selectable with a switch or use a blend like Dragons Breath.

 

[Feral Feline]

Since it's already built, it would not make sense to socket input cap and risk damaging the board; however with a set of alligator-clip wires and a small selection of caps...

Attach the first cap, say 47n, to the gator clips, then running a looper or a reverb with tails touch the other ends of the clip-wires to the C1 solder joints. 9n6 + 47n parallel = 56n6. Try it again with your next bigger value cap and keep going until you have enough bass to your liking. When you've narrowed it down, solder-tack in that value and then while playing mess around with the controls some more to make sure you like that value at all settings.

I like Hamerfan's suggestion best though, on C1 either a pot or a switch for some versatility and the ability to go full stock.


You can also increase C3, though I'd do that in smaller increments than the large jump on C1. Maybe if you increase both a bit, you'll get the Goldilocks-solution.



As for other Guv'nor-based circs:

Eight-years old vid, probably lots more Marshall Guv'Nor derivatives on the market since this was shot:

Also check the Crunchbox and circuits based off it.

Some other odds 'n' ends:

Original Marshall Guv'Nor - Mod for more bass

Original Marshall Guv'Nor - Mod for more bass

www.diystompboxes.com

https://www.talkbass.com/threads/modded-guvnor-clone.1441500/
with link to a dead vid, but also a link to FuzzDog's clean blend mod

https://reverb.com/ca/news/say-ello-to-the-5-finest-marshall-guvnor-clones

Need more Bass on Guv'nor pedal.

I got an original UK made Guv'nor a while ago and have started using on my board, but the thing is it takes away a chunk of low end (unlike the crowther hotcake im also using), even with the bass pot all the way up it still lacks enough bottom end wallop. So what i need is to know which...

www.marshallforum.com

Quick point, it's a Governator, with an "r" — I was sure I'd DL'd the build doc but didn't find it when I cut'n'pasted the thread-title into my search.

 

[Spiff4565]

Since it's already built, it would not make sense to socket input cap and risk damaging the board; however with a set of alligator-clip wires and a small selection of caps...

Attach the first cap, say 47n, to the gator clips, then running a looper or a reverb with tails touch the other ends of the clip-wires to the C1 solder joints. 9n6 + 47n parallel = 56n6. Try it again with your next bigger value cap and keep going until you have enough bass to your liking. When you've narrowed it down, solder-tack in that value and then while playing mess around with the controls some more to make sure you like that value at all settings.

I like Hamerfan's suggestion best though, on C1 either a pot or a switch for some versatility and the ability to go full stock.


You can also increase C3, though I'd do that in smaller increments than the large jump on C1. Maybe if you increase both a bit, you'll get the Goldilocks-solution.



As for other Guv'nor-based circs:

Eight-years old vid, probably lots more Marshall Guv'Nor derivatives on the market since this was shot:

Also check the Crunchbox and circuits based off it.

Some other odds 'n' ends:

Original Marshall Guv'Nor - Mod for more bass

Original Marshall Guv'Nor - Mod for more bass

www.diystompboxes.com

https://www.talkbass.com/threads/modded-guvnor-clone.1441500/
with link to a dead vid, but also a link to FuzzDog's clean blend mod

https://reverb.com/ca/news/say-ello-to-the-5-finest-marshall-guvnor-clones

Need more Bass on Guv'nor pedal.

I got an original UK made Guv'nor a while ago and have started using on my board, but the thing is it takes away a chunk of low end (unlike the crowther hotcake im also using), even with the bass pot all the way up it still lacks enough bottom end wallop. So what i need is to know which...

www.marshallforum.com

Quick point, it's a Governator, with an "r" — I was sure I'd DL'd the build doc but didn't find it when I cut'n'pasted the thread-title into my search.

Yeah, I always drop the r . Don't ask me why as it continuely screws my searches up.

Thanks for the info, will be building another GuveRnator in the near future. I'll give these mods a go.

 

[HamishR]

You can increase the size of the input cap (C1) but sometimes this leads to unintended consequences, such as a fuzzier low end. Sometimes this is cool, sometimes it's annoying.

I too have wanted more low end from the Guvernator and found that simply increasing C3 to 220nF has done the trick for me. I have tried 470nF but it's a bit borish - 330nF might work for you. But for me 220nF is fine.

 

[cdwillis]

Hamish has the right idea. The only issue is increasing the C3 cap will sound great, but once you have the thing maxed out it might sound muddy, so you'll have to find a sweet spot for that cap value.

I doubt you're going to see any difference changing the input cap. The 9.6nf cap and 1m resistor form a high pass filter with a knee around 16hz. The fundamental of a guitar's low E string is around 80 or 82hz, I can't remember exactly.

If you can socket or even breadboard the entire circuit I'd try fiddling with the caps in the tone section. Maybe increase c7 to 10nf so that you let more bass through the treble control itself, change c11 or c10 too. I never really wrapped my head around how the tone stack on this circuit works because it's different than the Marshall amp tone circuits.

 

[Feral Feline]

Cool. I look forward to trying those tone-section mods.

Seems instead of putting C1 extra-cappage on a switch or parallel pot-path would be better done to C3.

So the 16Hz 9n6/1M still has all the bassists covered — low E on a Bass is 41Hz and if it's a 5- or 6-stringer low B booms at 31Hz — but it makes me wonder why something like the AMZ boost, which Mr Orman assures bass players the stock input cap of 1n is covering all freqs ... yet Catalinbread took that circuit and pumped the input up to a whopping 10n (Sagrado Poblano Picoso). I've even seen the same circuit bass-stoked with 47n. Maybe at that point it's more to do with the impedance? Someday I'll figure this input cap/impedance thing.

 

[HamishR]

Another thing I did recently to the Guvernator was to remove the hard clipping LEDs and use the Bluesbreaker way of clipping. The whole 6K8 and four 1N4148s between pins 6 and 7. Along with the 220nF cap at C3 it sounds amazing, but at a cost. It sucks up a lot of level so I'm having to run volume pretty much wide open. The LED hard clippers let a lot more through than my setup!

So obviously this is why a lot of designers add a gain recovery stage if they mess with the Guv'nor. CDWillis is right too - if you're not careful the very interactive EQ can get rather muddy or really harsh once you start to fiddle with the circuit. But set just right it can sound great.

 

[HamishR]

As a direct result of this thread I built another Guvernator today. This time I built it stock, except for using a 220nF cap at C3 and leaving off the 470pF cap at the end. It sounds great! The 220nF cap is perfect for me. If I use gain at noon or lower with my Les Paul I can have bass and mids at around noon, treble a bit higher and it sounds fuller and better balanced than stock. If you push the gain to around 3.00 you can increase bass and treble a bit for a killer ZZ Top sound. There is plenty of low end on tap.

The red LEDs seem to sound really good in this circuit. Normally I really don't like LEDs as clipping diodes - maybe it's because they are being used as hard clippers in this circuit? Normally they're used in the feedback loop and there's something about the sound which really annoys me.

 

[Feral Feline]

Most circuits that I can think of that use LEDs use them as hard-clippers to ground; in a feedback loop the 1N4148 immediately comes to mind.

Reminds me of the thread where somebody said all the on-on-on seem to be type 2, and all I ever seem to find is type 1.

 

[HamishR]

Maybe I've built too many BJF pedals! For example (and this is typical for BJF) in the Honey Bee there are two LEDs used as clippers in the feedback loop then two 1N400x used as hard clippers in the next stage. Maybe I should just swap 'em around?

 

[jesuscrisp]

If you do so, the signal clipped by the silicon soft clippers will be rather quiet so the LEDs won't do a lot

 

[HamishR]

Good point. FWIW I have built some of these pedals with the 1N400x diodes on a switch so that I can hear the difference and while it is subtle it does make a difference. Swapping them around might make it even more subtle. As in inaudible. It's fascinating really - Removing the second gain stage clipping makes the sound better for note definition but lessens the "amp sound".