how to mod my pico to stepped pots

[skal1]

ok, so i am dipping my toe's into mastering, and i was wondering if i could convert my variable pot pico to a stepped affair.

i know roger has got these on the road already so i it is doable .


First questions are what are the range;s of the ratio ,makeup,threshold , attack and release pots.

what maths do i need to do to work out the range on a stepped switch.

Would i have to change any resistors on the main pcb ,to set the range for the stepped pot's.


cheers

skal

 

[Gold]

It's much easier to measure the resistance of the pot at the steps you want than to try to calculate it.  You could also just take the total value of the pot and divide into as many steps as you have on your switch. For gain you probably want even dB steps. For attack and release exact values don't matter too much.

 

[ruairioflaherty]

First questions are what are the range;s of the ratio ,makeup,threshold , attack and release pots.

What Paul said.  I mastered for many years with a larger Pico that had only stepped output and it worked fine.  If you take careful notes you could still work quite happily with pots.  The advantage of switches on the output is that you can match sides quickly rather than having to use tones as you do with pots.

 

[pucho812]

lets do these the easy way. If you know the value of the pot and know if it is linear or audio taper, then check this out.

Here is a resistor value list for making audio/log taper stepped pots. It lists for 24 position pots
http://www.goldpt.com/r_series.html

It also give instructions for making linear stepped pots.

Their stuff is easy to use and fairly compact. I have made several items for people using these.

 

[Gold]

The controls on the pico are altering DC control voltages, not audio. The Goldpoint chart doesn't really apply.

 

[pucho812]

The controls on the pico are altering DC control voltages, not audio. The Goldpoint chart doesn't really apply.

oh well never mind then....

 

[skal1]

i  thought so ,would i have to use a voltage to dbu or dbv chart?


skal

 

[ruairioflaherty]

For any of the linear pots you just divide the total resistance into even steps. 

I have to say though that I think this is more work than it's worth for you right now.  Put stepped switches on the output gains and see how you go, I could and have worked with that.

 

[Gold]

i  thought so ,would i have to use a voltage to dbu or dbv chart?

Read the THAT app notes. It goes through all the math. You are dealing with converting an AC signal to a DC control voltage and then scaling to  the behavior of the VCA. The VCA is 6.5 mV/dB IIRC. Or you could just do as we are suggesting.

 

[skal1]

ok going to do more research  ha ha.

thanks lads


skal