Adding trimpots to Wah - setting value? Andreas...

[dap99]

The DIY forum doesn't get as much traffic so I'm dbl posting b/c I'm that impatient.

 

I did the mods on Andreas' page.

 

Now I want to go back in there and put trimpots where he suggests, but I just have one question -

 

He writes:

 

"Just remember to set them to the correct value before installing, so you

[melx]

i'm only guessing (from my limited knowledge) but I guess you need to set the resistance (or whatever it is) with a meter.

[SUPER VELCROBOY]

where's the link to the mod?

[dap99]

 

where's the link to the mod?

 

 

This would help, wouldn't it?

 

Down towards the bottom :poke:

[andreas]

 

i'm only guessing (from my limited knowledge) but I guess you need to set the resistance (or whatever it is) with a meter.

Exactly. It is much easier to get going, if you've already set the trimpot somewhere in the range you think you'll end up. For the gain mod, I'd use a 470 ohm trimpot, set to about 350 ohms or so. For the mid/Q mod, you'll have to use a 4.7Kohm trimpot (it's the closest standard value available), and I'd start out at 1.8Kohm or so. Another tip is to, while you're measuring, mark out on the trimpot itself a couple of reference values (for instance the stock value, and the highest/lowest value you think you'll be using).

 

That way, you can start fine-tuning right away, without getting lost trying to find a baseline setting.

 

/Andreas

[dap99]

 

Exactly. It is much easier to get going, if you've already set the trimpot somewhere in the range you think you'll end up. For the gain mod, I'd use a 470 ohm trimpot, set to about 350 ohms or so. For the mid/Q mod, you'll have to use a 4.7Kohm trimpot (it's the closest standard value available), and I'd start out at 1.8Kohm or so. Another tip is to, while you're measuring, mark out on the trimpot itself a couple of reference values (for instance the stock value, and the highest/lowest value you think you'll be using). That way, you can start fine-tuning right away, without getting lost trying to find a baseline setting. /Andreas

 

 

Thanks Andreas! On the web page you suggest a 100k to replace the 33k resistor, but now you suggest a 4.7Khohm? Am I missing something? Also, I can't seem to find a 4.7Kohm, but I can find a 5Kohm - close enough?

 

Lastly, does it matter which outer leg I use w/ the center leg of the trimmer?

 

Thanks again for all your help!

[andreas]

Oh, for the "Q" mod, a 100K would definitely be the right choice. I was talking about the midrange adjustment (1.5K stock value), where a 4.7K or 5K would be right.

 

It doesn't matter which outer leg you cut off - it will change what happens as you turn the pot clockwise (if the resistance increases or decreases), but as long as the trimpot is the linear type, it won't matter.

 

/Andreas

[dap99]

Oh, for the "Q" mod, a 100K would definitely be the right choice. I was talking about the midrange adjustment (1.5K stock value), where a 4.7K or 5K would be right. It doesn't matter which outer leg you cut off - it will change what happens as you turn the pot clockwise (if the resistance increases or decreases), but as long as the trimpot is the linear type, it won't matter. /Andreas

 

My bad. Thanks again for the support. Now that I've got my wheels turnin', I think I'm going to order the BYOC board and the extra parts that I need. I think in the long run, it'll save me a lot of time/energy b/c the BYOC PCB is so neatly laid out. Thanks again - and my friend thanks you b/c he LOVES the wah I modded for him using your page :thu: