# Pro-10 Green mods - about that low-end!



## HamishR (Nov 7, 2021)

I built my second Pro-10 Green today. The first I built stock to see what all the fuss was about. It helped me identify how I might want to change a few things...  And one of the mods from Aion FX worked a treat! 

The things which I wanted to change were (1) the ridiculous amount of low end. Usually I want to increase it so at least that's a change. And (2) I wanted slightly less compression in the clipping. I prefer a little more punch in my dirt.

So the first change was easy. I populated the board but didn't put R7 (1K5) on the top of the board. Instead I installed the 1K5 resistor underneath the board, going from the end which connected to the chip to pin 3 of a C50K pot - this is the left-hand end of R7 looking at the top of the board. Then pin 2 went to the underside of the other end of where R7 was supposed to be - connecting to the positive end of C5. It's the right hand end of R7 if you look at the top of the board. Essentially all I did was insert a C50K pot between R7 and C5, just as Aion do on their version of the Nobels Drive. This works really well - now I have a bass and treble pot and can really lose a lot of that over-bearing low end, or keep it all by maxing out the bass pot. Simple.

I also used short lengths of wire to connect the tone pot so that now it's positioned under the gain pot rather than right in the middle.

Now to the compression. All I needed to do was replace D1 and D2 with a pair of diodes each. You could use 1N914s but I went with a 1N4148 into a 1N4001 on each side. Now the dirt is punchier and less compressed - actually it's just about perfect for me. In the Aion build docs they suggest doubling up the diodes in the hard clipping section (D3&4) but I'm perfectly happy with where I did it.

I hope these simple mods help others building this pedal. It's a cool pedal!

This has worked out really well for my tastes. It's a lot more usable in my rig now.


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## Coloso (Nov 17, 2021)

Hello HamishR, hey thanks for the mods, how much different is from the og pedal? Or how much changes there are between them?


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## HamishR (Nov 17, 2021)

As far as the tone is concerned with the bass pot on full it sounds pretty much exactly the same as stock. So if you like everything except the amount of low end just add the pot - all you're adding is a pot and some wire. I placed the new bass pot under the volume pot and used some wire to place the treble pot under the gain pot.

With the extra diodes (to me) it sounds a little more natural but the tone is much the same. The feel is different - it's less squishy.


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## Barry (Nov 17, 2021)

Is there any reason to not just sub the pot for the resistor? It's a 50K pot does a 1.5 K resistor in series really have an effect?


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## HamishR (Nov 17, 2021)

I guess not! I was just following the way they did it at Aion. I basically just used the resistor as a wire to the pot. You may well have 1k5 of resistance in the pot at minimum setting anyway.


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## Barry (Nov 17, 2021)

HamishR said:


> I guess not! I was just following the way they did it at Aion. I basically just used the resistor as a wire to the pot. You may well have 1k5 of resistance in the pot at minimum setting anyway.


Good point it may get ugly without that as a minimum


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