Second master volume / solo volume without REMOTE1 or MIDI
Minus booster or volume pedal
The 2ND MASTER VOLUME function of the AMP1, which can be called up using the REMOTE1 or MIDI, is suitable for a sound-neutral increase (or decrease) in the volume of the AMP1. If the use of REMOTE1 or MIDI is not possible or desired, we recommend using a minus booster or a volume pedal in the serial effects loop to control the overall volume.
A minus booster is a pedal with a passive volume control and a switch to activate this control. Position the minus booster in the serial FX loop of the AMP1 as the last pedal in the effects chain. Since the minus booster reduces the volume, it should be switched on for the rhythm volume and switched off for the solo volume.
There are several products suitable for this purpose, including the Minus Booster II from ORION effects, the Signal Pad from Electro Harmonix or the Little Black Amp Box from JHS Pedals.
Why not a normal Clean Boost?
If the effect loop of the AMP1 is set to serial, you can always use a normal clean boost for a second master volume, but this option is usually not sound neutral: When using a booster in the effect loop, not only the volume is increased, but also the saturation the tube-driven power amplifier. This changes the sound.
So if you want to achieve a second master volume without changing the sound, it is best to use a volume pedal or a minus booster. Both reduce the volume instead of increasing it, which means that the sound remains unchanged.
If you still use a normal Clean Boost, you should make sure that the FX Loop Level switch on the underside of the AMP1, with which the sensitivity of the effect loop can be set, is set so that it does not change the sound of your pedal in the loop! To enable the greatest possible headroom, the switch should be pressed (+ 4dB).