Patent ID: 7522735

Claim:
An electronic circuit for adding reverberation effects to an audio signal generated from an external high impedance source and passing the reverberated signal at a predetermined impedance for input into an external sound device, said electronic circuit comprising, in combination: (a) a reverberation effects circuit having pre-amplifier/driver and recovery amplifier sections and a spring reverberation device coupled thereinbetween, said pre-amplifier/driver section having an input jack for receiving therethrough a high impedance signal produced from an external audio source, a DC isolation filter, and a low impedance, high current output for input into said spring reverberation device having an output for passing a low impedance signal to said recovery amplifier section for increasing the impedance of the signal to a level acceptable for input into the external sound device, said spring reverberation device employs three springs with each of said springs having a first spring end and a second spring end and each of the three first spring ends connected to a single first spring end connecting bar, and each of the three second spring ends connected a second spring end connecting bar, said pre-amplifier/driver section comprises first and second operational amplifiers each having inverting and non-inverting inputs and an output, each of said outputs comprising a negative feedback loop coupled to said inverting inputs and shunted to ground for setting a predetermined gain value at said output, said first operational amplifier comprises a switch at said non-inverting input for controlling the audio signal path through said reverberation effects circuit and a path to ground comprising resistive capacity for maintaining an impedance level into said first operational amplifier and keeping the audio source from being loaded.