Parts · Transistors

BC109B

Si NPN BJT TO-18 / TO-92 TH.13 circuits use this part. Listed as: Semiconductors; Silicon transistor.

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

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
BC109B	200	20 V	100 mA	0.3 W	150 MHz

Used on other boards here

Part	hFE min	Vce	Ic	Pc	fT	Boards
BC108B	200	20 V	100 mA	0.3 W	150 MHz	20
BC239	200	20 V	100 mA	0.3 W	150 MHz	7
BC238B	200	20 V	100 mA	0.3 W	150 MHz	2
BC239B	200	20 V	100 mA	0.3 W	150 MHz	1
BC149	200	20 V	200 mA	0.25 W	150 MHz	6
BC149B	200	20 V	200 mA	0.25 W	150 MHz	1
BC349B	200	20 V	100 mA	0.3 W	125 MHz	1
BC319	200	20 V	150 mA	0.31 W	100 MHz	2

Closest by the numbers

Part	hFE min	Vce	Ic	Pc	fT
BC239A	200	20 V	100 mA	0.3 W	150 MHz
BCY57	200	20 V	200 mA	0.3 W	150 MHz
BC148B	200	20 V	200 mA	0.25 W	150 MHz
BC408B	200	20 V	100 mA	0.25 W	150 MHz
BC409	200	20 V	100 mA	0.25 W	150 MHz
BC409B	200	20 V	100 mA	0.25 W	150 MHz
BCF29B	200	20 V	200 mA	0.25 W	165 MHz
BCF92	200	20 V	200 mA	0.25 W	165 MHz

Circuit	Based on	Category	Vendor	Box	Knobs	Price	BOM
Fuzzz Boxx Turret board2×8 BC109B Sam Ash Fuzzz Boxx	Sam Ash Fuzzz Boxx	Fuzz	Amplified Parts	—	3	—	12
Black Effects Pedals Dry Line Driver Vero18×14 Unverified BC109B · BC109C Black Effects Pedals Dry Line Driver	Black Effects Pedals Dry Line Driver	Fuzz	Dirtbox Layouts	—	5	—	28
Fuzzhead Fx Pink Goat Vero Verified BC109B · BC109C Fuzzhead Fx Pink Goat	Fuzzhead Fx Pink Goat	Fuzz	Dirtbox Layouts	—	3	—	29
Red Witch Fuzz God 2 Vero15×12 Verified BC109B · BC109C Red Witch Fuzz God II	Red Witch Fuzz God II	Fuzz	Dirtbox Layouts	—	4	—	25
Schaller Fuzz Silicon Vero12×8 Verified BC109B Schaller Fuzz Silicon	Schaller Fuzz Silicon	Fuzz	Dirtbox Layouts	—	2	—	16
Parasit Studio Stepping Stone Overdrive Perfboard Verified BC109B · J201 · MPSA13 Parasit Studio Stepping Stone Overdrive	Parasit Studio Stepping Stone Overdrive	Overdrive	Effects Layouts (blog)	—	3	—	25
Schaller Fuzz Perfboard Verified BC109B Schaller Fuzz · 1590A	Schaller Fuzz	Fuzz	Effects Layouts (blog)	1590A	2	—	16
60s and 70s Wah Variations BC109B	—	Wah / Envelope	Experimentalists Anonymous	—	—	—	19
Fuzzhead FX Pink Goat BC109B · BC109C	—	Fuzz	Moonn Electronics	—	3	€5.50	45
Vox Clyde McCoy Wah Vero BC109B Vox Clyde McCoy Wah · Wah rocker shell	Vox Clyde McCoy Wah	Wah / Envelope	Revolution Deux	Wah rocker shell	1	—	22
FYA Electronics Apiformis Fuzztortion Vero Verified BC109B FYA Apiformis Fuzztortion	FYA Apiformis Fuzztortion	Fuzz	Tagboard Effects	—	3	—	30
Red Witch Fuzz God II Vero14×11 Verified BC109B · BC109C Red Witch Fuzz God II	Red Witch Fuzz God II	Fuzz	Tagboard Effects	—	4	—	24
VOX Repeat Percussion VeroTagboard 2N2646 · BC108A · BC109B Vox Repeat Percussion	Vox Repeat Percussion	Tremolo	turretboard.org	—	2	—	20