The G.X.40 replaced the E.R. 40 in 1975 as WEM's mid-size 40watt solid state amplifier head., to be used for either guitar or bass guitar. It was a single channel/two input amplifier which incorporated some of the features used on the Sapphire 100 combo, these being controls for Bass on Bass, Treble on Treble, Presence, and Compression, as well as the normal volume, treble. bass, and middle tone controls.
