a lot of amps have two channels where you can set one for rhythm, and the other for lead, with a foot switch to flip between the two. It looks like the AD30 has that setup ?
How you set the channels is up to you, of course.
However there are other factors. Let's say you have your rhythm amp sound as clean with a little bit of 'crunch', and your lead sound with more distortion and slightly higher in volume so it pokes through. Pretty standard setup.
What if you want a really clean sound halfway through a song ? You can often turn the volume knob on the guitar down a smidge, which normally reduces the 'crunch' and only slightly takes the volume down (less drive to the amp = less overdrive [crunch]).
But it you want a fully clean sound in the middle of the song, then maybe you're stuck.
Some amps I've played through at jams have a "Clean" setting on the footswitch as well (kind of a notional channel) so you have channels :
- Clean (no settings - or at least no overdrive)
this would help, obviously.
As the amp itself is doing the distortion, and this is one part that manufactrers concentrate on, it's likely that it'll have a good sound, and importantly, will be the sound that you heard when you tried the amp in the shop.
The alternative is to have separate effects boards where you switch on each effect as you see fit. This is my preference, but my hand is forced because my amp only has a clean channel, so I have to use effctes for overdrive etc.
- Clean : No effects.
- Rhythm: Use the overdrive pedal.
- Lead: Activate a compressor whcih gives a chunky sound & is a little louder than rhythm.
That way I can switch from crunch to clean instantly and push lead in as I see fit. Note that the effects are individual, as opposed to a bank of effects saved to memory.
This works really well but the possible downside is that not all distortion / overdrive pedals sound that great, and it's sometimes a stroke of luck to find one that sounds good with your amp (as opposed to the amp in the shop).
That's using individual effcts- one on/off footswitch per pedal.
The alternative is to have a multi effects board with all this built-in, with banks of memorised 'patches' that you've defined already eg you could define a patch for clean, rhythm and lead. As some songs nee da bit more of this or less of that, you could define further patches with effects amended accordingly.
Some of the more flexible units still allow you to switch parts of the patch in/out - eg you might like a certain patch but want to take the overdrive out. Other (normally cheaper) ones just allow you to set the patch up and use it as-is. To change the soud you have to switch between patches.
I guess the most flexible would be to use effects and a multi channel amp meaning you can choose between the effects overdrive or the amp's. Not sure why that would be better though, plus a rule emerges in music : the more knobs there are, the more chance there is of getting it wrong.