Renoise is great for controlling external hardware via MIDI. I am a Logic user, but I use Renoise almost exclusively when it comes to sequencing MIDI. I’ve even started sequencing Logic’s internal synths/samplers using Renoise and the IAC bus (if you’re going to play around with routing MIDI between programs on OSX, I also recommend downloading the excellent and free MIDIPipe: http://homepage.mac.com/nicowald/SubtleSoft/)). In my opinion, nothing out there beats Renoise in speed or flexibility when it comes to programming audio (playing it in live is another matter).
As for how to set things up:
Your audio interface will ultimately dictate the possibilities of your setup. I have a very modest 4 in/2 out Presonus Inspire. I use the external MIDI port on my MPD24 to hook up all my external kit (Ensoniq SQ-80, ESQ-1 multitimbral synths, Alesis D4 drum rompler, Boss SP-303 sampler, a couple Yamaha QY-70’s w/ onboard XG synths). Whatever sound modules I happen to be using at the time get patched into a Mackie VLZ 1202 mixer.
The mixer has a main and an aux bus. I use the main bus for a total mix of everything being triggered externally. This mix goes into my computer through the first two inputs on my interface. It is brought into Renoise through a Line-In plugin that has been loaded onto a dedicated track. Meanwhile, the mixer’s aux bus outputs have been connected to the second two inputs of my interface. If I need to record a particular instrument for whatever reason, I bus the synth/sampler to the aux outputs on the mixer and set Renoise to record audio on the second two inputs of the interface. Once it’s inside Renoise, I can subject it to all the usual sequencing and pattern effect trickery.
The limitations of my interface make it a total hassle to use with outboard effects. (I can only route to a single stereo out on my interface. In order to get a send/return thing going, and still be able to hear everything else through my speakers, I need to use OSX’s aggregate device to gang the internal audio to the Presonus, then use my computer’s headphone out as the send. Yech.)
If, however, you have multiple ins and outs on your interface, you can do things a couple of ways. The most flexible is to dedicate a Renoise send track to your outboard effects channel by choosing the appropriate output on your interface in the “Routing” drop down for that send track. Rename the send something you’ll remember like “ext. fx send”. Then dedicate a regular track to serving as a return by adding a Line-In plugin on it and setting it to the inputs on your interface that the signal is to return through (the reason for a dedicated regular track is you can’t use Line-In plugs on Renoise’s send tracks). Rename this track something you’ll remember like “ext. fx return.”
Now, if you want to send virtual instruments or sampler sounds on a Renoise track out to the external effect, simply add a Send plugin on the track you’d like to send. Select “Mute Source” on the Send plugin if you’d like the external effect to act as an insert, or “Keep Source” if you want to use it as a traditional send. If you want to use an external synth or something with this routing setup, you’d need a dedicated Line-In plugin for that sound source on the track to get the sound into Renoise, at which point you can use the above process to “effect” it. (Of course, you will need a separate input for that particular sound source if you want the effect to be applied to it, alone, as opposed to your whole external gear mix, if you have a setup similar to mine.)
There’s a lot of fun stuff you can do with routing (including controlled feedback, dub techniques, and other things). An external mixer used together with the computer can make things a lot more fun and interesting. The thing I like best about using external gear with Renoise is being able to sequence quickly, twiddle my hardware’s knobs live as I record my external sounds into Renoise, and then chop, rearrange, and generally fiddle with the sample inside Renoise.
Hope this helps out.
/ J