processing recorded audio via external instruments

Hi guys -
I want to be able to process previously recorded audio via an external piece of hardware. So I need Cubase to be able to PLAY the audio, while simultaneously RECORDING the new audio. This seems rather basic, but I can’t get it to work. I get an error.

Any set-up suggestions / walkthroughs would be most appreciated.

I’m running Cubase 9 via a Focusrite 18i20.

Hadn’t done external processing in years but my guess would be to route the output audio track to a specific output on the 18i20, then connect that to the processor input. Cable the processor output to an assigned input on the 18i20. Make sure the output audio track is routed correctly to the output connected to the processor and that the input routing of the recording track is correctly connected to the assigned recording input on the 18i20. Depending on the particular processor, you should see that you are receiving an audio signal from the 18i20 when Cubase is playing. If so, you should also be seeing an audio signal on the recording track in Cubase. Make sure record is enabled on that track. Engage record and it should work.
If you are still getting an error, check your Cubase routing, your cable connections and make sure the 18i20 is programmed correctly for that routing.
Also make sure that your processor is making the round trip.

Really appreciate that info, Suprawill. Thanks so much. I BELIEVE that’s what I’ve done, and hearing your describing it affirms I’m in the right territory. I trying again, checking all my connections, etc. To me, the issue seemed to be in Cubase… so I suspect some sort of digital routing is off. Many thanks again.

Read the section on “External FX” in the manual. That is the best way. That way you can ping the hardware and it automatically adjusts for any added latency from going D/A and back A/D again.

Excellent – Thanks Gravely!