How fast are the pot inputs?

Hardware questions and issues with the FV-1

Moderator: frank

Post Reply
Neutron7
Posts: 2
Joined: Tue Jun 15, 2010 8:44 pm

How fast are the pot inputs?

Post by Neutron7 »

Hello, I have just ordered the dev board and was wondering if i can send real time control voltages (as from a modular synthesizer) to to POT control inputs (obviously I would have to scale them and limit them to 3v)

Would it read the pot values smoothly enough so there would not be any clicks or pops?

Some of the voltages are slower things like envelopes or LFOS but i might also want to modulate them with audio frequency.
frank
Posts: 1244
Joined: Wed Oct 19, 2005 12:26 pm
Contact:

Post by frank »

The pot inputs have about a 100mS time constant so may limit your use in this case.
Frank Thomson
Experimental Noize
Neutron7
Posts: 2
Joined: Tue Jun 15, 2010 8:44 pm

Post by Neutron7 »

Thanks for your quick reply.


what about using one of the audio inputs as a control voltage? I would have to omit the input coupling capacitor and be careful with not exceeding the supply, but it looks like i may be able to use one of the inputs as a "fast" modulation source.

I think the easiest way to protect the inputs is probably to have an input buffer (ADA4091-2 overvoltage protected op amp) off the 3v supply.
frank
Posts: 1244
Joined: Wed Oct 19, 2005 12:26 pm
Contact:

Post by frank »

Audio inputs are designed for AC only, putting DC in will not work correctly. To do something like this you would want to use the envelope of the input as the control voltage. So make an oscillator, run it through a pot to control amplitude and in the program extract the envelope to use as the control signal.
Frank Thomson
Experimental Noize
Post Reply