# Nobleman bass mod



## skrattadu (Apr 11, 2021)

Hey guys, I'm looking to add a switch for some different bass response values to my ODR1 clone. Which cap(s) control the bass in the Nobleman?

Thanks!


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## Feral Feline (Apr 13, 2021)

What are you trying to accomplish? 
Is there too much low end and you're trying to tighten it up for guitar, or are you hoping to mod it to make it more friendly to bass playing?

In the signal path: C1, C6, C19, C20, C21

Indirectly shaping bass response, I suppose C4, C5, C18... Then there's all the caps shaving off highs that shape the overall sound of the circuit, ie how the lows are perceived, the complex tone control... — there's a lot going on. 


From what I've read, it's a bassy circuit. Nonetheless, as a bass player I might need more! If you need even more bass, I'd approach it thusly:


Bass Boost
Remove C1. From its input pad on the PCB, run a wire to lug 2 of a DPDT on-off-on switch.

From Lug 1 to Lug 4, attach a 100n cap.
From Lug 2 to Lug 5, attach the stock 100n cap.
From Lug 3 to Lug 6, attach a 220n cap.

Run a wire from Lug 5 back to C1's output pad on the PCB. 

You now have 320n in the toggle's up position, stock 100n in the middle position, and 200n in the down position. 
You can adjust the caps to taste, whatever sounds good to your ear,



Bass Reduction
Replace R7 (1k5) with a B50k pot. You could try A50k and C50k, too, see where you want the meat of the "bass" control's rotation to sit.

In addition, you could add the C1 switch, but obviously with different cap values:

Lug 1 to Lug 4, attach a 56n cap.
Lug 2 to Lug 5, attach a 47n cap.
Lug 3 to Lug 6, attach a 27n cap.

That'd give you: Up 74n, Middle 47n, and Down a stock-ish 103n. 




That's about as much as I'd be willing & able to tinker with the circuit without seriously upsetting its design-balance. Anything more than above and I'd want to fully breadboard the circuit to toy with C3, C11, C16 or Spectrum-related caps etc. I don't know enough to target other specific RC networks, I'd just be trial&error pluggin&playin and using my ears. Actually, I'd use my friend's ears, his are much better nuanced than mine.


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## skrattadu (Apr 13, 2021)

Thanks! I'm just looking to cut a little bass out, because it is indeed a little bass heavy.


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## Chuck D. Bones (Apr 16, 2021)

Take a look at the Aion Andromeda, it has a bass control added on.  I built one, works great.

https://forum.pedalpcb.com/threads/odr-1.3007/


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## Feral Feline (Apr 30, 2021)

😹 Aion was where I headed to straight after reading the OP!
I should've given due credit.


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## EZS (Jan 2, 2023)

How I implemented a trim pot. 1.5k to 50kb trim to 2.2u to gnd. Heres some photos. Ive yet completed this build due to missing a few cap values. But I hope this may help someone in the future.


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## cdwillis (Jan 2, 2023)

Change C5 to 220nf.


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