Put your Fender Twin into standby mode. This attenuates the flow of voltage to the tubes and disengages the speakers. The standby switch is on the rear of the amplifier, next to the power switch.
Turn the “Master” dial down to zero. This way, when you power up, any problems arising from broken cables do not cause an unexpected and loud noise. It is best to turn your amp on with the volume minimized, and then gradually increase the volume to your preferred level.
Connect the supplied power adapter to the back of the VG88.
Connect a 1/4-inch instrument cable to the “Guitar In” jack on the back of the VG88.
Connect the other end of the same cable to your guitar. To reduce the chances of the guitar cable slipping out if you step on it, loop it over your guitar strap. This provides tension relief.
Connect a second 1/4-inch instrument cable to the “Guitar Output L (MONO)” jack on the rear of the VG88. Although the Fender Twin has four inputs, they are not designed for simultaneous use, so use the mono output from the VG88 rather than the stereo output.
Attach the other end of the cable to your preferred input jack. The Fender Twin has two channels, each of which has two inputs. Input “1” for each channel is 6-db louder than input “2.” Select channel “1” for a clean sound; use channel “2” if you wish to utilize the Fender Twin’s on-board effects, which include vibrato and reverb. If you have a high-output guitar, such as a Gibson Les Paul, select any input. If you have a low-output guitar, such as a single-coil Fender Telecaster, take advantage of the 6-db boost by using input “1” on your preferred channel.
Turn the amplifier on and increase the “Master” dial to your preferred level. A level of “2” is perfectly adequate for bedroom playing.