The Dual 40 (Model 6740)  is a two channel guitar amplifiers that mixes a great mid 60’s American clean tone with a late 60’s British tone.  There is a ton of versatility in this amp.  The Brit channel is reminiscent of an early plexi with the ability to add a cascaded gain channel for that extra bit of drive.  Both channels have a mid boost function and full tone stack.  A very usable master volume rounds out the front panel controls.