EXTC-SA

From Radial Engineering:

The EXTC-SA is a unique interface for connecting guitar pedals to the inputs and outputs of pro audio equipment such as recording interfaces or mixing consoles, allowing you to incorporate your pedals in new and creative ways.

The EXTC allows you to get creative with your effects pedals, using them in your mix on any recorded track. Add a touch of distortion or chorus to a lead vocal, flange on a violin, or fuzz on piano - the possibilities are endless. The EXTC takes the line level balanced output of your recording interface and converts it to an instrument level high-Z output optimized for guitar effects pedals, so you can Reamp any track through your pedalboard with ease. Once you've run the signal through your pedals, connect the output back into the EXTC and it will boost it up to a balanced line level so you can connect directly to the input of your recording interface. The EXTC features Radial's class-A buffer for the best audio quality and transformer isolation to eliminate any buzz or hum - so you can focus your attention on using your pedals in new and exciting applications.

Take a dry track, send it to the EXTC which in turn feeds your pedals. This is the perfect way to add some extra zest to a vocal track; an envelope follower to a kick; or some wah to that Hammond.