Manley SLAM! Mastering Version Features:

• No mic preamps or instrument inputs. Instead the tube sections are paralleled for lower noise and distortion
• All pots are replaced with rotary switches for detented resettability and easier calibration
• The mastering version has a true hard-wire bypass function, which is not possible on the regular version with mic preamps, etc. What was the Left Bypass, becomes the full Bypass (in stereo and hardwired). No separate L & R bypass buttons
• There are dedicated unbalanced transformerless inputs on the mastering version. What was the Phantom Power switch on the back now selects XLR or 1/4" inputs
• The ELOP limiter now has 5 ratios, which may put it into the compressor/limiter category. The lower ratios may be better suited for complex mixes
• The FET limiter has 5 modes (these last two features replace the INPUT selector)