Parts · Transistors

2N4125

7 circuits use this part. Listed as: BJT transistor, PNP TO-92; TO-92 Inline Wide-large-solderpads.

Substitutes Si PNP 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
2N4125	50	30 V	200 mA	0.31 W	200 MHz

Used on other boards here

Part	hFE min	Vce	Ic	Pc	fT	Boards
2N3905	50	40 V	200 mA	0.31 W	200 MHz	1
2N2907	35	40 V	600 mA	0.4 W	200 MHz	22
2N5138	50	30 V	100 mA	0.2 W	40 MHz	1
2N5401	60	150 V	600 mA	0.31 W	100 MHz	1
2N3638	30	25 V	500 mA	0.3 W	100 MHz	1
2N4403	100	40 V	600 mA	0.31 W	200 MHz	4
BC558	75	25 V	100 mA	0.5 W	75 MHz	1
2N3906	100	40 V	200 mA	0.31 W	250 MHz	113

Closest by the numbers

Part	hFE min	Vce	Ic	Pc	fT
BCY72	50	25 V	200 mA	0.35 W	200 MHz
BCY72AQ	50	25 V	200 mA	0.35 W	200 MHz
2N5382	50	40 V	200 mA	0.36 W	200 MHz
BC291	50	40 V	100 mA	0.36 W
2SA1518	50	50 V	500 mA	0.3 W	200 MHz
2SA1519	50	50 V	500 mA	0.3 W	200 MHz
2SA1520	50	50 V	500 mA	0.3 W	200 MHz
2SA1521	50	50 V	500 mA	0.3 W	200 MHz

Circuit	Based on	Category	Vendor	Box	Knobs	Price	BOM
DOD FX75 2N4125 · 2N5089 · J111 · J113	DOD FX75	Flanger	Experimentalists Anonymous	—	—	—	4
Phase-R 2N4125 · 2N5952 · TL022 · TL072	MXR Phase 90/45	Vibrato / Chorus	Five Cats Pedals	1590B	2	£4.50	55
P90 2N4125 · 2N5952 · LM741	MXR Phase 90	Phaser	General Guitar Gadgets	1590B	—	$15.00	54
Dr. Phybes v4 2N4125 · 2N5952 · TL061 · TL074	—	Phaser	GuitarPCB	—	1	$8.95 out	55
Whiteboard 2N4125 · BC548	Jext Telez White Pedal	Fuzz	PCB Guitar Mania	125B	4	€11.90 out	51
Conqueror Fuzz 2N4125 · BC548	Jext Telez White Pedal	Fuzz	PedalPCB	125B	5	$12.00	51
XC Phase 2N4125 · 2N5952 · TL022 · TL072	MXR Phase 90	EQ / Filter	PedalPCB	125B	3	$12.00 out	55