2 different sounds

[jofranari]

What do I need to change separately the sound of each group of strings to have it both different at the same time?

[rockola]

What do I need to change separately the sound of each group of strings to have it both different at the same time?

If I understood your question correctly, you're asking: how do I get two different sounds from a tapping instrument with two groups of strings? If your instrument is one of the "standard" ones, it has a stereo output, and so you can simply route each channel to a different effect, amp or whatever. If I misunderstood your question, please clarify.

[jofranari]

To route each channel to a different effect (to have two differents kinds of distorsion simultaneously) do I need two preamps or it´s enough with only one? Is there any preamp with stereo input to do that?

[Jersey Ray]

Generally speaking, you'll need two pre-amps, or two amps.

If you really want a big-*** sound, I'd recommend getting pre-amps from different manufacturers, for most variety.

[DigiGuitar]

There is another way. Try http://www.guitarfx.net
This thing is stereo. You can use different gain, distortion, EQ settings, reverb, chorus, flanger on left and right chanels, and get realy different sound from left and right chanels. it's very easy to tune this thing to get, say, clean sound from the left and hard distorted form the right chanels. Then you can amplify resulted stereo signal by any even hi-fi stereo system or use headphones.