Son of Ben Preamp

Based on the Benson Preamp· 3 other boards clone it

From the vendor

Controls

• Volume

• Drive

• Treble

• Bass

Specifications

• Designed for a 125B enclosure with top-mounted jacks

Documentation

The schematic is in the vendor's build document, page 4. Open the build document. No KiCad fragment has been drawn for this circuit yet.

Ref	Value	Normalized	Type	Notes
Resistors 14
R1	1M	1M	Resistor, 1/4W
R2	220K	220k	Resistor, 1/4W
R3	1M	1M	Resistor, 1/4W
R4	1K	1k	Resistor, 1/4W
R5	10K	10k	Resistor, 1/4W
R6	470K	470k	Resistor, 1/4W
R7	470K	470k	Resistor, 1/4W
R8	1K	1k	Resistor, 1/4W
R9	10K	10k	Resistor, 1/4W
R10	100K	100k	Resistor, 1/4W
R11	1K	1k	Resistor, 1/4W
R12	10K	10k	Resistor, 1/4W
R13	47K	47k	Resistor, 1/4W
R100	4K7	4.7k	Resistor, 1/4W
Capacitors 12
C1	100n	100n	Film capacitor, 7.2 x 2.5mm
C2	22n	22n	Film capacitor, 7.2 x 2.5mm
C3	250p	250p	Ceramic capacitor
C4	470p	470p	Ceramic capacitor
C5	10u	10u	Electrolytic capacitor, 5mm
C6	22n	22n	Film capacitor, 7.2 x 2.5mm
C7	22n	22n	Film capacitor, 7.2 x 2.5mm
C8	22n	22n	Film capacitor, 7.2 x 2.5mm
C9	2n2	2.2n	Film capacitor, 7.2 x 2.5mm
C10	10u	10u	Electrolytic capacitor, 5mm	*Optional (see Page 3)
C100	100u	100u	Electrolytic capacitor, 5mm
C101	100n	100n	Film capacitor, 7.2 x 2.5mm
Diodes 1
D100	1N5817	1N5817	Schottky diode, DO-41
Transistors 3
Q1	J201	J201	JFET transistor, N-channel	*Alternate MMBFJ201 (SMD)
Q2	J201	J201	JFET transistor, N-channel	*Alternate MMBFJ201 (SMD)
Q3	J201	J201	JFET transistor, N-channel	*Alternate MMBFJ201 (SMD)
Potentiometers 4
VOLUME	A100K	A100k	16mm right-angle PCB mount pot
DRIVE	A1M	A1M	16mm right-angle PCB mount pot
TREBLE	A250K	A250k	16mm right-angle PCB mount pot
BASS	***	***	***	* Refer to Page 3
Trimmers 3
TRIM1	50K	50k	Trim potentiometer	3362P-style
TRIM2	50K	50k	Trim potentiometer	3362P-style
TRIM3	50K	50k	Trim potentiometer	3362P-style