Parts · Transistors

BC557A

Si PNP BJT TO-92 TH.2 circuits use this part.

Datasheet · from onsemi.com

Substitutes Si PNP 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
BC557A	125	45 V	100 mA	0.5 W	75 MHz

Used on other boards here

Part	hFE min	Vce	Ic	Pc	fT	Boards
2SA1015Y	120	50 V	150 mA	0.4 W	80 MHz	4
TIS93	100	40 V	400 mA	0.625 W		4
BC560	110	45 V	100 mA	0.5 W	150 MHz	8
MPS8598	100	60 V	200 mA	0.35 W	150 MHz	1
PN2907	100	40 V	600 mA	0.4 W	200 MHz	5
2N4403	100	40 V	600 mA	0.31 W	200 MHz	11
2N3906	100	40 V	200 mA	0.31 W	250 MHz	324
2SA1015	70	50 V	150 mA	0.4 W	80 MHz	8

Closest by the numbers

Part	hFE min	Vce	Ic	Pc	fT
BC405A	125	50 V	150 mA	0.35 W	75 MHz
BC417A	125	45 V	200 mA	0.25 W	75 MHz
BC274A	125	45 V	100 mA	0.3 W	65 MHz
BCX79	120	45 V	100 mA	0.45 W	100 MHz
BCX79VII	120	45 V	200 mA	0.45 W	100 MHz
BCW69LT1	120	45 V	200 mA	0.3 W	75 MHz
BC251A	120	45 V	100 mA	0.3 W	80 MHz
BC478A	125	40 V	150 mA	0.36 W	100 MHz

Faceplate	Circuit	Based on	Category	Vendor	Box	Knobs	Price	BOM
	Carlin Compressor/Fuzz Vero22×21 Unverified 2N5457 · BC548B · BC557A Carlin Compressor/Fuzz	Carlin Compressor/Fuzz	Compressor	Dirtbox Layouts	—	3	—	33
	Carlin Compressor 2N5457 · BC548B · BC557A	—	Compressor	Moody Sounds	—	4	kr765.00	50