Universal Audio's Century Tube Channel Strip was part of the 9.7 UAD update and may have slipped past a few people as its not got the badge of branded emulation. However, its got plenty of character and vibe to add especially when combined with the Apollo Unison technology.
Producer Steve Evans, a UAD user, though not so far in the world of Apollo and Unison, applied it to a songwriting session and was impressed with the vibe it added at the point of recording his demo, Usually something he defers until the mix phase and something that Apollo can offer as real-time input processing. His only gripes seemed to be that there should have been more direct control of some of the plug-ins controls via the Apollo itself. We we agree, would seem to make sense.
The Century Tube Channel Strip comprises of the Tube Preamp, Equalizer, Opto Leveller and Master section. With a simple set of controls, you can add the burn of the tubes on the input, sweeten with the EQ and add gentle or firm compression with the Opto leveller.
Our tests showed that it takes around 7% of DSP per instance on our Apollo QUAD.