Parts · Transistors

BC639

Si NPN BJT.2 circuits use this part.

Datasheet · from onsemi.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
BC639	40	80 V	1000 mA	1 W	50 MHz

Used on other boards here

Part	hFE min	Vce	Ic	Pc	fT	Boards
KSP42	40	300 V	500 mA	0.625 W	50 MHz	3
BD139	40	80 V	1000 mA	12 W	50 MHz	3
BD1396STU	40	80 V	1500 mA	12.5 W		1
BD13910STU	40	80 V	1500 mA	12.5 W		1
MPSA06	50	80 V	500 mA	0.625 W	100 MHz	6
2SD667	60	80 V	1000 mA	0.9 W	70 MHz	1
MPS-U05	60	60 V	2000 mA	10 W	170 MHz	1
MPSA06G	100	80 V	500 mA	0.63 W	100 MHz	1

Closest by the numbers

Part	hFE min	Vce	Ic	Pc	fT
2N2985	40	80 V	3000 mA	1 W	50 MHz
BCX40	40	80 V	2000 mA	1 W	50 MHz
BCX40-4	40	80 V	2000 mA	1 W	50 MHz
2N1893	40	80 V	500 mA	0.8 W	50 MHz
2N2243	40	80 V	1000 mA	0.8 W	50 MHz
BFR77	40	80 V	1000 mA	0.8 W	50 MHz
BFW33	40	80 V	500 mA	0.8 W	50 MHz
BSS32	40	80 V	500 mA	0.8 W	50 MHz

Faceplate	Circuit	Based on	Category	Vendor	Box	Knobs	Price	BOM
	Stretta BC639 · LF347 · LF347N · LT1054 Cicognani SexyComp 76 · 125B	Cicognani SexyComp 76	Compressor	Dead End FX	125B	6	$12.00	49
	Friedman Buxom Boost Vero23×24 Verified BC639 · LT1054 · TL072 · TL074 Friedman Buxom Boost	Friedman Buxom Boost	Boost	Tagboard Effects	—	5	—	39