The Garnet Li'l Rock amplifier is very similar electronically to a Tweed-era Fender Deluxe amplifier (the phase inverter tube in a Li'l Rock is a 6SN7). The taller cabinet is sealed only for the bottom 2/3rds of the 'speaker compartment', leaving the top chassis area open. The added height and closed back yields a little more bottom-end 'oomph' or push to the tone. Traynor took this idea to heart with their Guitar Mate amplifiers (see the Traynor section of Made in Canada). This is one my favorite Garnet amplifiers, because it is so portable, and has great tone. The 20 watts of output power may not be enough for most gigging situations, but it makes an excellent practice/recording amplifier. Similar to the Li'l Rock was the Mach 5 amplifier (basically a Li'l Rock with tremolo) which came out in three versions; 1) With a transformer 'impedance coupled' phase inverter. 2) With a 'normal' 6SN7 phase inverter. 3) With a 6SN7 phase inverter tube and a 6CG7 driving a Reverb circuit. This would be very close to a single-channel Deluxe Reverb, but at a considerable saving compared to today's prices for a vintage piece.