Explain this Showman circuit please

[Randall]

Can someone help me understand what is going on in the trem circuit with the extra 7025s? I don't understand how it works, or why all the 7025s. Extra gain stages? Quite different from the AB763 standard.

http://vintageampguide.com/schematics/s ... _schem.gif

[JazzGuitarGimp]

This is the famous Fender Brown era Harmonic Tremolo circuit. The guitar signal is split into high and low frequency bands, then each band is tremed out of phase with the other band, then the two signals are recombined. This trem circuit is said to have a phase-shifter kind of sound. I believe there are some youtube demos of this. Or you can go the www.strymon.net and listen to the demos of their Flint pedal, which has settings for all three of the Fender trem circuits. They are modeled in DSP, and from what my ears tell me, they did a pretty respectable job on the algorithms.