Ovation Instruments HEX Buffers and Logic Schematic Rev 1.0
Hexaphonic Guitar Preamp with Stereo Panning and VCA
HEX Buffers and Logic Schematic Rev 1.0 (42-224A)
Dual-rail supply with VREF (analog and digital reference voltages)
1995
US
12 components
4 diagrams
Four-sheet schematic for the Ovation HEX Pre-Amp system (product 42-224A, dated 7/18/95). Sheet 1: six individual piezo transducer buffer inputs using TL064 op-amps feeding a diode matrix with CD4017/CD4013 mode switching logic (PAN, ALT, AUTO SLOW/FAST, MONO, 2/4, 3/3 modes). Sheet 2: stereo L/R mixing network using 74HC4053 analog multiplexers with mono mix summing and VCA signal paths. Sheet 3: voltage-controlled amplifier stages for L/R channels with an LFO built around a 2N5930 transistor, plus analog and digital VREF generation. Sheet 4: stereo output stage with independent jack-actuated 1/4-inch output connectors for left, right, and combined stereo output with power-on switching.
Components
TL064 quad op-amp (IC2, IC3, IC4 - piezo buffers)
CD4017 decade counter (IC10 - mode sequencing)
CD4013 dual D flip-flop (IC11 - logic control)
74HC4053 analog multiplexer (IC5, IC6, IC7, IC8 - signal routing)
OC33 op-amps (mixing stages)
LM6024 quad op-amp (IC7 - VCA/LFO)
2N5930 transistor (LFO oscillator)
BAV70LT1 dual diodes (diode matrix)
DG768 analog switch (mono mode)
6x piezo buffer input stages (CN4-1 to CN4-7)
1/4 inch jack-actuated output switches
LED mode indicators (PAN, ALT, 3/3, 2/4)