Parts · Transistors

2N4123

Si NPN BJT TO-92 TH.2 circuits use this part.

Substitutes Si NPN transistor

Matched on material, polarity and the limits below from the transistor parameter database. Pinouts and packages are not in that data: check the datasheet before you drop one in, and expect gain to change the sound.

This part

Part	hFE min	Vce	Ic	Pc	fT
2N4123	50	30 V	200 mA	0.31 W	240 MHz

Used on other boards here

Part	hFE min	Vce	Ic	Pc	fT	Boards
2N3903	50	40 V	200 mA	0.31 W	250 MHz	15
2N3904	40	40 V	200 mA	0.31 W	300 MHz	870
MPSA05	50	60 V	500 mA	0.33 W	100 MHz	6
2SC1175	40	45 V	200 mA	0.3 W	170 MHz	1
PN100	40	35 V	500 mA	0.625 W	200 MHz	5
2SC536	60	30 V	100 mA	0.2 W	115 MHz	4
2N3053	50	40 V	700 mA	1 W	100 MHz	4
MPSA06	50	80 V	500 mA	0.625 W	100 MHz	6

Closest by the numbers

Part	hFE min	Vce	Ic	Pc	fT
BFV88A	50	30 V	800 mA	0.3 W	250 MHz
PN3905	50	40 V	200 mA	0.31 W	250 MHz
BFY28	50	30 V	200 mA	0.3 W	300 MHz
BSS66R	50	40 V	100 mA	0.3 W	250 MHz
2N6503	50	40 V	1000 mA	0.35 W	250 MHz
BSR17R	50	40 V	200 mA	0.35 W	250 MHz
2N5380	50	40 V	200 mA	0.36 W	250 MHz
2N2539	50	30 V	500 mA	0.5 W	250 MHz

Faceplate	Circuit	Based on	Category	Vendor	Box	Knobs	Price	BOM
	Fjord Fuzz Berserk V1 Vero15×12 Verified 2N3704 · 2N4123 · BC549 Fjord Fuzz Berserk V1	Fjord Fuzz Berserk V1	Fuzz	Dirtbox Layouts	—	3	—	20
	Hybrid Fuzz Driver Deluxe 2N4123 · BC549C · MP35 Skreddy Hybrid Fuzz Driver	Skreddy Hybrid Fuzz Driver	Fuzz	Naegele Audio	—	6	—	46