Parts · Transistors

MP37B

Ge NPN BJT TH.2 circuits use this part.

Substitutes Ge 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
MP37B	25	30 V	20 mA	0.15 W	1 MHz

Used on other boards here

Part	hFE min	Vce	Ic	Pc	fT	Boards
MP10B	25	30 V	20 mA	0.15 W	1 MHz	2
MP14B	30	30 V	20 mA	0.15 W	1 MHz	1
2N1302	20	25 V	300 mA	0.15 W	1 MHz	6
2SD77	40	25 V	100 mA	0.15 W	2 MHz	1
103NU71	45	48 V	250 mA	0.125 W	0.7 MHz	3
GT404B	60	25 V	500 mA	0.6 W	1 MHz	1

Closest by the numbers

Part	hFE min	Vce	Ic	Pc	fT
AC127Z	25	40 V	500 mA	0.175 W	1 MHz
AC340	30	24 V	50 mA	0.125 W	1 MHz
2N587	20	30 V	200 mA	0.2 W
AC330	20	24 V	50 mA	0.125 W	1 MHz
2N385	30	25 V	200 mA	0.15 W	2 MHz
NKT732	20	25 V	300 mA	0.15 W	2 MHz
2N438	20	25 V	300 mA	0.1 W	1.5 MHz
2SC128	30	25 V	200 mA	0.15 W	3 MHz

Faceplate	Circuit	Based on	Category	Vendor	Box	Knobs	Price	BOM
	EarthQuaker Devices Dream Crusher Vero13×12 Verified MP37B EarthQuaker Devices Dream Crusher	EarthQuaker Devices Dream Crusher	Fuzz	Dirtbox Layouts	—	2	—	19
	Annihilator Fuzz MP37B EarthQuaker Devices Dream Crusher · 1590B	EarthQuaker Devices Dream Crusher	Fuzz	Fuzz Dog	1590B	3	£33.60	19