Mudbunny MID control POT and noise gate mod questions. UPDATED

[Loztboy]

I'm about to build a Violet Rams head mudbunny.
1. I don't have a 25KB pot but I have some spare 100kA pots, how would a 100KA pot work for the MID control? I had to order some parts so I ordered a 25KB pot as well

2. How is the Violet Rams head compared to the other versions gain wise?

3. Could someone translate this to the mudbunny version?
Noise gate mod: This mod will quieten the Muff while not playing, thus a noise gate. To do this, add a 100k trimpot (wired as a variable resistor) parallel to the 100k to ground of the second gain stage (R14). The trimpot can be adjusted to taste to get the max noise gate effect.

[jkokura]

Don't know precisely, but it's worth trying! Try the pot out and tell us. It's usually an easy fix to switch it back, so there's not real harm.

Jacob

[Haberdasher]

Hey Trond

you can try soldering a 33k3 (or just 30k or so) resistor across from lugs 1 to 3 on that 100k pot.  100k and 33k3 in parallel is right at about 25k.  I've had decent results doing stuff like that in the past.  Maybe worth a try?

[Loztboy]

Thanks guys.
I will first try with a 100KA pot, then put a 33k resistor on it if it does not sound right.

How will the resistor affect the sweep or taper?

[Diamond]

Don't forget to also change the tone stack cap (C10 on the Mudbunny board) to 22nF! I don't think it's mentioned really clearly in the Mudbunny build instructions. The 22nF is essential for the mids pot to work. Check this site: http://rkerkhof.ruhosting.nl/Taas/Mods/Big%20Muff.htm A 10k pot also works really well btw. It goes from standard scoop to slightly mid boosted. A 25k pot gives you more midboost at the end of the turn.

[Loztboy]

Thanks Diamond.

[bigmufffuzzwizz]

I'm about to build a Violet Rams head mudbunny.
1. I don't have a 25KB pot but I have some spare 100kA pots, how would a 100KA pot work for the MID control? I had to order some parts so I ordered a 25KB pot as well

I usually use a 20kb pot, it's whats easily available for me to source. I find that above a certain point it doesn't continue to add more mids/presence so its not a problem..Change the 4nf to 22nf and 39k (on the same side of the tone stack) to 3.3k. This will give you a good sweep with the mids knob. It works a lot on the treble side, adding a big body to the sizzly sound.

2. How is the Violet Rams head compared to the other versions gain wise?

It's hard to explain it in gain wise, I feel the structure of the tone make up is different between different versions while gain can be adjusted via a few component(transistors, all 4 emitter resistors and maybe even diodes). Rams head has tighter bass, a bit less sustain but a very aggressive attack to it. The Violet version seems to have more sustain and some other slight changes. To increase gain jumper the 3 emitter resistors (they are 100 ohms in VRH version). You can jumper the last emitter resistor (2.7k) for gain in the last gain stage, never tried it cause i get more than enough from the first three but it could be interesting. Also increasing the limiting resistors (8.2k x 2) will allow more gain into the clipping stages but it changes how the pedal sorta sounds. More high gainy, crunchy, I wanna compare it to a chunk chunk. Fun to play around with this stuff!

3. Could someone translate this to the mudbunny version?
Noise gate mod: This mod will quieten the Muff while not playing, thus a noise gate. To do this, add a 100k trimpot (wired as a variable resistor) parallel to the 100k to ground of the second gain stage (R14). The trimpot can be adjusted to taste to get the max noise gate effect.

Yea its really simple. Connect two legs of the trimpot or pot (1+2 or 2+3) in parallel to 100k, meaning the lugs tied together go to one side of the resistor and the other lug goes to the other side. Didn't notice this mod before but I'll have to try it! Thanks

[Loztboy]

Thanks.

[Loztboy]

Noise gate mod question:

If I connect lug 1 and 2 of the 100k trimpot to one side of the 100k resistor an lug 3 to the other side i will get 50k max.
Is it supposed to be like this?

[bigmufffuzzwizz]

Noise gate mod question:

If I connect lug 1 and 2 of the 100k trimpot to one side of the 100k resistor an lug 3 to the other side i will get 50k max.
Is it supposed to be like this?

The math is correct (2 100k in ll would be 50k) and going by the quote you posted yes it should be right.
Have you tried it yet? I have a built muff board around, I could probably try it with a pot.

[Loztboy]

I'm not done yet, waiting for some parts.
What I don't get is that the stock value is 100k and the mod makes it a variable 50k.
Why not just use only a 100k trimmer?

[bigmufffuzzwizz]

I'm not done yet, waiting for some parts.
What I don't get is that the stock value is 100k and the mod makes it a variable 50k.
Why not just use only a 100k trimmer?

Good question. It could be that by doing that your spreading the turn of the knob out getting more of desired sweep. Some experimentation is in order!