Adding Footswitch Control for Glide
A modification which might prove useful (especially for the performing musician) is adding a jack to the 2720-9 Glide circuitry to allow footswitch control.
The footswitch jack is placed in series with the switch on the glide potentiometer to allow a master on-off capability. The jack selected is a switching type (Switchcraft # 12-A or similar) providing for normal operation of the circuit when the footswitch is disconnected.
Note that the shaft connection (mounting bushing) of the footswitch jack must be insulated from ground. This is accomplished in 2720-8 and 4762 cases by mounting the jack in a hole drilled in the wooden case to the left of the Glide face plate.
Wire the jack into the circuitry before mounting in position to the left of the Glide face plate. Circuit modifications are shown in the drawing below.
PAIA's funky "Foot Switch" or any Foot Switch intended for use with guitar amps are suitable. There are two different types of switches which can be used, each providing different control capabilities. The "Standard" footswitch, employing a push-on, push-off switch, enables you to tap the switch once to have Glide and again to turn it off. A Momentary-Contact, Normally open type switch will allow the glide effect to remain off until the switch is pressed. When released the glide effect ceases. This allows the addition of glide to selected notes or passages making them musically more interesting.