Parts · Transistors

2SD77

Ge NPN BJT TH.1 circuit uses 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
2SD77	40	25 V	100 mA	0.15 W	2 MHz

Used on other boards here

Part	hFE min	Vce	Ic	Pc	fT	Boards
2N1304	40	20 V	300 mA	0.15 W	4 MHz	4
103NU71	45	48 V	250 mA	0.125 W	0.7 MHz	3
AC176	52	20 V	1000 mA	0.22 W	1 MHz	20
2N388	60	20 V	200 mA	0.15 W	7 MHz	2
GT404B	60	25 V	500 mA	0.6 W	1 MHz	1
2N1302	20	25 V	300 mA	0.15 W	1 MHz	6
2SD352	100	30 V	1000 mA	0.6 W		2

Closest by the numbers

Part	hFE min	Vce	Ic	Pc	fT
2N1012	40	22 V	100 mA	0.15 W	3 MHz
NKT734	40	20 V	300 mA	0.15 W	4 MHz
AC350	40	32 V	125 mA	0.125 W	1 MHz
2N1732	40	20 V	300 mA	0.15 W	5 MHz
2N1000	40	25 V		0.15 W	6 MHz
2N377	35	20 V	200 mA	0.15 W	3 MHz
2SC182	45	20 V	100 mA	0.125 W	3 MHz
2N385	30	25 V	200 mA	0.15 W	2 MHz

Faceplate	Circuit	Based on	Category	Vendor	Box	Knobs	Price	BOM
	Yellow Hybrid Tone Bender 2SD77 · BC109 · BC109C Colorsound Yellow Hybrid Tone Bender · 125B	Colorsound Yellow Hybrid Tone Bender	Fuzz	Naegele Audio	125B	3	—	45