Parts · Transistors

2N4125

Si PNP BJT TO-92 TH.18 circuits use this part. Listed as: BJT transistor, PNP TO-92; TO-92 Inline Wide-large-solderpads.

Datasheet · archived copy from NTE; the part is discontinued and the maker no longer publishes it

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	6
BC212L	50	50 V	200 mA	0.3 W	200 MHz	1
2N4402	50	40 V	600 mA	0.31 W	150 MHz	4
BC186	40	25 V	100 mA	0.3 W	200 MHz	2
MPSA65	50	30 V	300 mA	0.625 W	100 MHz	2
BC213L	70	30 V	200 mA	0.3 W	200 MHz	1
2N3702	60	25 V	200 mA	0.36 W	100 MHz	5
PN200	40	35 V	500 mA	0.625 W	150 MHz	1

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
Jext Telez White Pedal Vero21×21 Verified 2N4125 · BC548 Jext Telez White Pedal	Jext Telez White Pedal	Distortion	Dirtbox Layouts	—	4	—	34
MXR Phase 90 Vero21×26 Verified 2N4125 · 2N5952 · TL062 MXR Phase 90	MXR Phase 90	Vibrato / Chorus	Dirtbox Layouts	—	1	—	28
Jext Telez White Pedal Perfboard Verified 2N4125 · BC548 Jext Telez White Pedal · 125B	Jext Telez White Pedal	Fuzz	Effects Layouts (blog)	125B	4	—	39
MXR Script Phase 90 Perfboard Verified 2N4125 · 2N5952 · 741 MXR Phase 90	MXR Phase 90	Phaser	Effects Layouts (blog)	—	1	—	21
DOD 908A 2N4124 · 2N4125 · 2N5089 · 4042B DOD 908A	DOD 908A	Delay	Experimentalists Anonymous	—	—	—	50
DOD FX60 1458 · 2N4125 · 2N5088 · 4007 DOD FX60	DOD FX60	Vibrato / Chorus	Experimentalists Anonymous	—	2	—	53
DOD FX75 2N4124 · 2N4125 · 2N5089 · CD4007 DOD FX75	DOD FX75	Flanger	Experimentalists Anonymous	—	—	—	51
Digitech PDS2020 (PDF) 2N4125 · 2N5088 · 4007A · 4024 DigiTech PDS2020	DigiTech PDS2020	Delay	Experimentalists Anonymous	—	5	—	241
Digitech XP100 2N4124 · 2N4125 · 4464 · 74AC04 DigiTech XP100	DigiTech XP100	Vibrato / Chorus	Experimentalists Anonymous	—	—	—	196
Phase-R 2N4125 · 2N5952 · TL022 · TL072 MXR Phase 90/45 · 1590B	MXR Phase 90/45	Vibrato / Chorus	Five Cats Pedals	1590B	2	£4.50	55
Dr. Phybes v4 2N4125 · 2N5952 · TL061 · TL071	—	Phaser	GuitarPCB	—	1	$8.95 out	58
Whiteboard 2N4125 · BC548 Jext Telez White Pedal · 125B	Jext Telez White Pedal	Fuzz	PCB Guitar Mania	125B	4	€11.90 out	52
Conqueror Fuzz 2N4125 · BC548 Jext Telez White Pedal · 125B	Jext Telez White Pedal	Fuzz	PedalPCB	125B	5	$12.00	51
XC Phase 2N4125 · 2N5952 · TL022 · TL072 MXR Phase 90 · 125B	MXR Phase 90	EQ / Filter	PedalPCB	125B	3	$12.00	55
Jext Telez White Pedal Vero28×17 Verified 2N4125 · BC548 Jext Telez White Pedal	Jext Telez White Pedal	Preamp / Amp-in-a-box	Tagboard Effects	—	4	—	35
MXR Phase 90 - 4 / 8 Stage Vero21×23 Unverified 2N4125 · 2N5952 · TL072 MXR Phase 90 - 4 / 8 Stage	MXR Phase 90 - 4 / 8 Stage	Phaser	Tagboard Effects	—	1	—	28
MXR Phase 90 with Script Switch Vero21×23 Verified 2N4125 · 2N5952 · TL072 MXR Phase 90	MXR Phase 90	Phaser	Tagboard Effects	—	1	—	23
MXR Phase 90 Pez 90 2N4125 · 2N5952 · TL072 MXR Phase 90	MXR Phase 90	Phaser	Tonepad	—	1	$11.00	19