In Stock. 45 Day Lowest Price - 100% Satisfaction Guarantee. Kustom Amplification, originally known for its upholstered Tuck n' Roll amplifiers which were an icon of 1960s and '70s rock music, has unveiled its first new guitar amp "stack" design. Called the QUAD Stack, the new set-up features an amplifier head based on the critically acclaimed Kustom QUAD 100DFX amp, but with a stage-ready, 100-watt power output and a few neat surprises