Ovation Electric Guitar Onboard Preamp Version F Schematic
Guitar Onboard Preamp / Active Pickup Circuit
Ovation Electric Preamp Version F
9V (dual 9V batteries, likely ±9V or 18V total)
1970s
US
39 components
This schematic depicts the Ovation Electric Preamp Version F, an onboard active guitar preamp circuit powered by dual 9V batteries. The circuit features three 2N5459 JFET transistors for signal amplification, a pickup selector switch (S1) with Neck, Bridge, and Both out-of-phase positions, and a notch filter section (S2) using a toroid inductor (L1). Various trim and tone controls are implemented via potentiometers and capacitor networks to shape the output signal delivered to a 1/4-inch output jack (J1).
Components
R1 - 750k trimmer
R2 - 50k trimmer
R3 - 150k
R4 - 10k
R5 - 475k
R6 - 221k
R7 - 150k
R8 - 100k
R9 - 475k
R10a - 750k linear pot
R10b - 250k log pot
R11 - 475k
R12 - 22.1k
R13 - 18.2k
R14 - 10k
R15 - 3.92
R16 - 5.62k
R17a - 100k linear pot
R17b - 100k linear pot
C1 - 1mf/50v
C2 - 1mf/50v
C3 - 0.047mf
C4 - 0.22mf
C5 - 0.0056mf
C6 - 0.0068mf
C7 - 100pf
C8 - 1mf/50v
C9 - 0.1mf
C10 - 10mf/25v
Q1 - 2N5459 JFET
Q2 - 2N5459 JFET
Q3 - 2N5459 JFET
T1 - Transformer (toroid-related)
L1 - 1H toroid inductor
B1 - 9v battery
B2 - 9v battery
S1 - 4P3T pickup selector switch
S2 - DPDT notch filter switch
J1 - 1/4 inch phone jack with normally-open switch (isolated)