Parts · Transistors

MMBT3904

Si NPN BJT SOT-23 SMD.2 circuits use this part.

Datasheet · from diodes.com

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
MMBT3904	40	40 V	100 mA	0.2 W	300 MHz

Used on other boards here

Part	hFE min	Vce	Ic	Pc	fT	Boards
2SC1175	40	45 V	200 mA	0.3 W	170 MHz	1
PN100	40	35 V	500 mA	0.625 W	200 MHz	5
2N3903	50	40 V	200 mA	0.31 W	250 MHz	15
2N4123	50	30 V	200 mA	0.31 W	240 MHz	2
2N3568	40	60 V	200 mA	0.3 W	60 MHz	1
BF244	30	30 V	100 mA	0.3 W	170 MHz	3
2N1613	40	50 V	600 mA	0.8 W	80 MHz	3
2N697	40	40 V	500 mA	0.6 W	50 MHz	1

Closest by the numbers

Part	hFE min	Vce	Ic	Pc	fT
2SC945R	40	50 V	150 mA	0.25 W	300 MHz
2SC4112	40	50 V	100 mA	0.2 W	250 MHz
2N4436	40	30 V	500 mA	0.2 W	250 MHz
BFJ67	40	40 V	1000 mA	0.36 W
BFJ68	40	40 V	1000 mA	0.36 W
KSC853	40	60 V	200 mA	0.25 W
BSS79B	40	40 V	800 mA	0.35 W	250 MHz
BFR71	40	55 V	200 mA	0.12 W

Faceplate	Circuit	Based on	Category	Vendor	Box	Knobs	Price	BOM
	Sputnik II/III 2N7002 · CJ3407-ES · GT310B · J201 Spaceman Effects Sputnik II · 1590BB2	Spaceman Effects Sputnik II	Fuzz	Naegele Audio	1590BB2	4	—	66
	Diamond Church Street Chorus PT2399-Based Tri-Chorus 2N7002 · ATTINY841-SSU · MMBT3904 · MMBT5088LT1G	—	Vibrato / Chorus	Scientific Guitarist	—	2	—	159