Description Product Description The Astoria Classic from Marshall will appeal to purists who want clean, authentic all-valve tone, and to boutique pedal enthusiasts who will find it the perfect pure-valve foundation for their sound. The Power Reduction pull switch drops the amplifier's output power from 30-watts to 5-watts, which produces softer tones and a less 'in your face' sound. The Sensitivity control optimises the sensitivity of the preamp by controlling its negative feedback. It increases or decreases gain without changing the output impedance of the first stage. This means that tonal integrity is preserved regardless of where the Sensitivity control level is set. Edge makes the overall characteristic sound of the amplifier brighter or darker. To achieve this, it cuts high frequencies between the phase splitter and the power valves. Edge is a power stage function with a similar effect to a traditional 'presence' control. Note that he higher the Master volume level, the more pronounced the Edge function will become.