Based on the Fender® Champ®
No Master–>100%, No Presence–> 0%, No Mid*, No Bass, No Treble
*In the tweed champ, the bass and treble are after the amp modeling, but the midrange control is between the two preamp gain stages. The midrange knob can become a cool drive feature.
The Fender Champ was a guitar amplifier made by Fender. It was introduced in 1948 and discontinued in 1982. An updated version was introduced in 2006 as part of the “Vintage Modified” line.
The Champ had the lowest power output and the simplest circuit for all of the Fender tube amps. The Champ had only one power tube, which meant that the circuit is single-ended and class A, single-ended (single 6V6 tube). Five watts and the simple toneful circuit allowed the Champ to be used easily and often in recording studios.
Tweed amplifiers typically break up earlier than later “cleaner” models and are known for their warm-sounding overdrive.