The Marshall AS50D is a compact and portable 50 Watt combo amplifier specially designed for use with acoustic instruments.
Between its two channels, the Marshall AS50D has the flexibility to handle instruments with transducers, such as piezo or magnetic pick-ups (channel 1), or microphone for either vocal or instrument reproduction (channel 2). The built-in Chorus effect is assignable to either or both channels and the Reverb can be controlled and balanced between the channels to create just the right ambience. If you want to add further effects, then there is an on-board parallel effects loop which can be balanced between the channels in the same way as the Reverb. The AS50D features several anti-feedback controls, including a Phase switch and a frequency controllable Notch Filter. The combination of these two elements will give you precise control of the frequencies where feedback is likely to occur and help you to eliminate them.