If you have an external preamp, or other line level signal that you'd like to record or monitor with the VRS8, you'll need to connect it to a line input on the VRS8.
The 1/4" inputs on the back of the VRS8 are LINE inputs (+4dBu) and will bypass the internal preamps.
Please note that even though the preamps are fully bypassed, you'll still have line level gain control with the input pots on the front panel.
Additionally, the 1/4" inputs, are dedicated line inputs and can not properly accept Hi Z Instrument inputs.
If you have any further questions, please contact support