The REDD.47 Mic Amplifier is a recreation of the original valve line amplifier used in Abbey Road studios heralded REDD.51 Console.
 
The REDD.47 adds an unmistakably punchy and aggressive character to a recording.

Check out these reviews and videos:

http://www.audiotechnology.com.au/wp/index.php/chandler-limited-redd-47-valve-preamplifier/

https://www.youtube.com/watch?t=20&v=QRoxG-Q5jc4

http://chandlerlimited.com/redd-47-pre-amp/