Parts · Transistors

BC108B

Si NPN BJT TO-18 / TO-92 TH.20 circuits use this part. Listed as: Silicon NPN 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
BC108B	200	20 V	100 mA	0.3 W	150 MHz

Used on other boards here

Part	hFE min	Vce	Ic	Pc	fT	Boards
BC109B	200	20 V	100 mA	0.3 W	150 MHz	13
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
Höfner Buzztone Turret board BC108B Höfner Buzztone · 1590N1	Höfner Buzztone	Fuzz	Amplified Parts	1590N1	—	—	9
Ace Tone FM-2 Fuzzmaster Stock Vero18×20 Verified BC108B Ace Tone FM-2 Fuzz Master	Ace Tone FM-2 Fuzz Master	Fuzz	Dirtbox Layouts	—	2	—	26
Black Effect Pedals Lava Machine Vero19×13 Verified 2N2222A · BC108B · BC109C Black Effect Pedals Lava Machine	Black Effect Pedals Lava Machine	Boost	Dirtbox Layouts	—	3	—	25
Fuzzhead Fx Harmonic Gyrolator Vero19×18 Verified BC108B · MP20A · TLC274 Fuzzhead Fx Harmonic Gyrolator	Fuzzhead Fx Harmonic Gyrolator	Fuzz	Dirtbox Layouts	—	5	—	38
Ghost Effects Lunar Incantaion Vero13×9 Verified BC108B Ghost Effects Lunar Incantaion	Ghost Effects Lunar Incantaion	Fuzz	Dirtbox Layouts	—	3	—	18
Ghost Effects Warmjet V Vero22×17 Verified BC108B · BC557 Ghost Effects Warmjet V	Ghost Effects Warmjet V	Fuzz	Dirtbox Layouts	—	3	—	28
Höfner Buzztone Vero14×11 Unverified BC108B Höfner Buzztone	Höfner Buzztone	Boost	Dirtbox Layouts	—	2	—	15
Minotaur Sonic Terrors Fuzz & Burn Vero Verified BC108B · BC547A · BC548C Minotaur Sonic Terrors Fuzz & Burn	Minotaur Sonic Terrors Fuzz & Burn	Distortion	Dirtbox Layouts	—	2	—	26
Spaceman Effects Gemini IV Vero26×25 Unverified 2N2222A · 2N5088 · AC128 · AC176 Spaceman Effects Gemini IV	Spaceman Effects Gemini IV	Fuzz	Dirtbox Layouts	—	6	—	46
Spaceman Effects Rumblefuzz II Vero15×14 Verified 2N2222A · BC108B Spaceman Effects Rumblefuzz II	Spaceman Effects Rumblefuzz II	Fuzz	Dirtbox Layouts	—	3	—	28
WEM Project V Vero24×17 Verified BC108B · BC186 WEM Project V fuzz	WEM Project V fuzz	Fuzz	Dirtbox Layouts	—	2	—	41
Höfner Buzz Tone Perfboard Verified BC108B Höfner Buzztone	Höfner Buzztone	Fuzz	Effects Layouts (blog)	—	2	—	13
Lumpy's Tone Shop Lemon Drop/ZII/Series 7 Perfboard Verified 2N5457 · BC108B Lumpy's Tone Shop Lemon Drop OD · 1590B	Lumpy's Tone Shop Lemon Drop OD	Preamp / Amp-in-a-box	Effects Layouts (blog)	1590B	3	—	22
High Quality Transistor Preamp BC108B · BC109C · BC178B	—	Preamp / Amp-in-a-box	Experimentalists Anonymous	—	1	—	19
Siren 2N3702 · BC108B	—	Ring Mod / Synth	Experimentalists Anonymous	—	—	—	13
Synbal 741 · BC108B · CA3080 · CD40106	—	Ring Mod / Synth	Experimentalists Anonymous	—	8	—	91
Syntom II 1458 · 78M12 · BC108B · CA1458	—	Ring Mod / Synth	Experimentalists Anonymous	—	—	—	87
WEM (Watkins) Project V Fuzz Vero BC108B · BC186 WEM Watkins Project V Fuzz	WEM Watkins Project V Fuzz	Fuzz	Revolution Deux	—	4	—	53
Yellow-Rumped Fuzz 2N2222A · BC108B Spaceman Effects Rumblefuzz II · 125B	Spaceman Effects Rumblefuzz II	Fuzz	RWL Pedals	125B	3	—	33
Hofner Buzztone Vero20×8 Unverified BC108B Höfner Buzztone	Höfner Buzztone	Fuzz	Tagboard Effects	—	2	—	12