Both 1U rack units, the Red 4Pre has four microphone pre-amps and is capable of 58 inputs and 64 outputs but for larger sessions, go with the Red 8Pre with eight mic pre-amps including two front panel instrument inputs. The Red 8Pre will handle a total up to 64 inputs and 64 outputs including 16 analog inputs and 18 analog outputs.

A significant and noteworthy feature on both of these new Focusrite Red units is the Air-enabled Red Evolution microphone preamplifier. These have Focusrite's unique 'Air' effect--the sound of the transformer-based mic preamps in the classic Focusrite ISA range. The ISA range pre-amps are noted for their pristine audio performance with a super low noise specification at -129dB EIN and up to 63dB of gain.

Besides conventional front panel controls using multi-function controls and a color LCD display, you can also use the Focusrite Control software for remote control. It's similar to the control software for Focusrite's Clarett line and now it's iOS capable. Focusrite Control allows for the storage and recall of all settings. You may set stereo linking, configure the built-in high-pass filter, engage polarity invert and select individual phantom powering for each of the microphone inputs. This is an important detail for owners of vintage or new passive ribbon microphones that should not have phantom power applied to them.

These new Focusrite Red Pre Interfaces represent the epitome in professional interface design and superb sound recording quality from Focusrite. Both the Red 4Pre and Red 8Pre Interfaces are solid, great-sounding units with classic microphone pre-amps and make future-proof investments in superb sound. I highly recommend them!

The Focusrite Red 4Pre sells for $2,499.99 with more about it at: https://us.focusrite.com/thunderbolt-audio-interfaces/red-4pre.