Parts · Transistors

KC508

Si NPN BJT.1 circuit uses this part.

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
KC508	125	20 V	100 mA	0.3 W	175 MHz

Used on other boards here

Part	hFE min	Vce	Ic	Pc	fT	Boards
BC108	120	20 V	100 mA	0.3 W	150 MHz	56
BC108A	120	20 V	100 mA	0.3 W	150 MHz	3
S8050	120	25 V	500 mA	0.3 W	150 MHz	1
BC183	120	30 V	200 mA	0.3 W	150 MHz	7
BC183A	120	30 V	200 mA	0.3 W	150 MHz	3
BC238	110	20 V	100 mA	0.3 W	150 MHz	2
PN4124	120	25 V	200 mA	0.625 W	170 MHz	2
BC182	120	50 V	200 mA	0.3 W	150 MHz	7

Closest by the numbers

Part	hFE min	Vce	Ic	Pc	fT
BC208A	125	20 V	100 mA	0.3 W	150 MHz
BC386A	125	20 V	100 mA	0.3 W	150 MHz
BCAP08	125	20 V	100 mA	0.3 W	150 MHz
BCAP08A	125	20 V	100 mA	0.3 W	150 MHz
BC585	120	20 V	100 mA	0.35 W
BC173	125	25 V	100 mA	0.3 W	150 MHz
BC173A	125	25 V	100 mA	0.3 W	150 MHz
BC268	125	20 V	1000 mA	0.375 W	150 MHz

Faceplate	Circuit	Based on	Category	Vendor	Box	Knobs	Price	BOM
	Tesla AYZ 025 (Fuzz section) Vero18×19 Unverified KC508 Tesla AYZ-025 Fuzz Wah	Tesla AYZ-025 Fuzz Wah	Fuzz	Dirtbox Layouts	—	3	—	28