Peavey TubeFex Operation Manual page 12

3. Using a separate preamp, distortion box, or effects processor in the Tube Fex effects loop.
If you wish to use the Tube Fex with some added outboard effects processing, such as the I+avey
amplifier, respectively.
Note: For mono operation use only the Left/Mono jacks in the steps shove.
Classic 41 OE
Chapter 1 Setup