# Spirit Box w mods



## ADAOCE (Feb 2, 2021)

Just finished up this spirit box. I like it quite a bit. I did the fuzzdog mods to get unity volume and to allow it to self oscillate. The dwell knob makes it oscillate to the moon so it’s probably better to do the momentary footswitch thing but it still works ok if you dial it in right you get this subtle background feedback that sounds nice. Had to use a B5k for the depth pot so it’s a bit much at the full clockwise rotation but I like dialing mix back anyways on delay and reverb.

what I didn’t expect from some of the demos is the subtle modulation I’m hearing which is actually kind of nice. Since I use the SLO for most things this is nice to have to turn on when I’m using the dream mode latching pad on the SLO (it bypasses the SLO while latched).

It’s a grey powder coat from Tayda and I used a flat white rattle can for the white part.


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## Regular Sean (Mar 1, 2021)

Correct me if I'm wrong, but the Fuzzdog mods are R5 to 18k and R17 to 12k which is R4 and R8 on the pedalpcb board, right? Or did I read the schematic wrong?


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## ADAOCE (Mar 1, 2021)

Regular Sean said:


> Correct me if I'm wrong, but the Fuzzdog mods are R5 to 18k and R17 to 12k which is R4 and R8 on the pedalpcb board, right? Or did I read the schematic wrong?



That sounds about right. I did exactly the blue highlighted mods in the fuzz dog pdf and I just matched it the component numbers to the schematic. They were drawn like exactly the same. Oh and the dwell knob is B25k. Kinda makes the oscillation nuts you may be fine leaving that as is


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## Regular Sean (Mar 1, 2021)

ADAOCE said:


> That sounds about right. I did exactly the blue highlighted mods in the fuzz dog pdf and I just matched it the component numbers to the schematic. They were drawn like exactly the same. Oh and the dwell knob is B25k. Kinda makes the oscillation nuts you may be fine leaving that as is


Oh I didn't even notice the pot. I think I've got a couple b25ks. Maybe I'll fire the iron up later and see if it makes the pedal more usable. Cheers, man.


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## ADAOCE (Mar 1, 2021)

Regular Sean said:


> Oh I didn't even notice the pot. I think I've got a couple b25ks. Maybe I'll fire the iron up later and see if it makes the pedal more usable. Cheers, man.



Yeah on second thought I think the pot may be pretty useful. It especially helps if you want to do the momentary footswitch mod. With the dwell maxed out on my pedal it gets pretty crazy. The weirdest thing I didn’t cover was that subtle modulation. Maybe I’m just hearing things but it has a spooky quality to it. Definitely not just a spring tank simulation


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## Paradox916 (Mar 1, 2021)

ADAOCE said:


> Just finished up this spirit box. I like it quite a bit. I did the fuzzdog mods to get unity volume and to allow it to self oscillate. The dwell knob makes it oscillate to the moon so it’s probably better to do the momentary footswitch thing but it still works ok if you dial it in right you get this subtle background feedback that sounds nice. Had to use a B5k for the depth pot so it’s a bit much at the full clockwise rotation but I like dialing mix back anyways on delay and reverb.
> 
> what I didn’t expect from some of the demos is the subtle modulation I’m hearing which is actually kind of nice. Since I use the SLO for most things this is nice to have to turn on when I’m using the dream mode latching pad on the SLO (it bypasses the SLO while latched).
> 
> It’s a grey powder coat from Tayda and I used a flat white rattle can for the white part.


I will have to look those mods up. I built a spirit box and its a decent reverb but I was wishing for a little something more when I built it and the fuzz dog mods sound exactly what I’m looking for.


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## ADAOCE (Mar 1, 2021)

It makes it a lot more useable I think. It’s definitely a one trick pony though even if it is a very nice sounding trick. Paired up with my walrus SLO and the analog tank on my amp I’m well covered.


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## felipesareas (May 5, 2022)

Hey guys, I'm a noob on Reverb pedals. This is the first project with a Belton Brick I'm building...

How does exactly the fuzzdog mod acts? I mean which role do R4 and R8 and the potentiometer play on the circuit?

replacing resistors is easy so I'll likely try both options and see it. But replacing a potentiometer is way harder (specially if you suck at desoldering as I do). So I was thinking what should I expect if I use the default pot for "Dwell" with the fuzzdog resistors


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## ADAOCE (May 6, 2022)

felipesareas said:


> Hey guys, I'm a noob on Reverb pedals. This is the first project with a Belton Brick I'm building...
> 
> How does exactly the fuzzdog mod acts? I mean which role do R4 and R8 and the potentiometer play on the circuit?
> 
> replacing resistors is easy so I'll likely try both options and see it. But replacing a potentiometer is way harder (specially if you suck at desoldering as I do). So I was thinking what should I expect if I use the default pot for "Dwell" with the fuzzdog resistors


Hey there make sure if you are doing the fuzzdog mods you match the resistor numbers from the fuzzdog pdf to the particular resistors in the PedalPCB schematic. The numbers are not the same. 

Honestly after having this pedal for a while I don’t care the dwell pot and oscillation mod. The unity biljme fix is a must but I think the pedal sounds fine stock. 

Search for @Danbieranowski thread about his momentary oscillation footswitch mod. This is a MUCH better way to do it


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## felipesareas (May 6, 2022)

Thanks a big lot for the reply 

I've checked the resistors to match fuzzdog. I was thinking of using an internal DIP witch or something alike so I could swap between stock and fuzzdog more easily (so that's why I was so into knowing if changing the pot or not would make a big difference in the whole mod)


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## ADAOCE (May 6, 2022)

felipesareas said:


> Thanks a big lot for the reply
> 
> I've checked the resistors to match fuzzdog. I was thinking of using an internal DIP witch or something alike so I could swap between stock and fuzzdog more easily (so that's why I was so into knowing if changing the pot or not would make a big difference in the whole mod)


I wouldn’t change the pot I think it’s really too much. I know there’s a way to do it with just a resistor change but I’m not sure exactly what that would be. Good luck!


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## felipesareas (May 6, 2022)

I see it. Thanks for the advice. I'll study the circuitry a little and see if I get any idea. Anyway I'm building 3, and two are going to be stock so I should be able to make good comparisons


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## mixographer (Jun 16, 2022)

I couldn’t get the dwell to do anything with the stock values. I went with a 10k resistor and a 10k linear pot.


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