en NPN Germanium transistor list for Fuzz pedals

Updated on June 26, 2019 | 798 Views No Category
0 on January 22, 2019

My interest in fuzz pedal came from JMI Tone Bender III reissue which belongs to a friend. this pedal has 3 of OC75 glass tube transistors.

And, unfortunately, My Sola Sound Bum Fuzz came with 3 of NPN transistors while OC75 is PNP type. then found this web page with germanium and silicone transistor lists


There are 26 of germanium NPN transistors from the data sheets

ASY28, ASY29

2N388, 2N388A

2N1302, 2N1304, 2N1306, 2N1308,

OC139, OC140, OC141



NKT713, NKT773, NKT774, NKT781


Black glass tube NPN transistors are OC139, OC140, OC141 from them.

OC75 is like this according to this web page on alltransistors.com

Type Designator: OC75 (PNP)

Maximum Collector Power Dissipation (Pc): 0.125 W

Maximum Collector-Base Voltage |Vcb|: 20 V

Maximum Collector-Emitter Voltage |Vce|: 20 V

Maximum Emitter-Base Voltage |Veb|: 10 V

Maximum Collector Current |Ic max|: 0.01 A

Transition Frequency (ft): 0.1 MHz

Collector Capacitance (Cc): 50 pF

Forward Current Transfer Ratio (hFE), MIN: 55

And, for OC139, OC140 is

Vcb: 20 V / 20 V

Vce: 20 V / 20V

Forward Current Transfer Ratio (hFE), MIN: 40 / 75

I’m going to try OC139. simply beccause, OC139 is cheaper than OC140 on ebay. and I’m wondering how Transition Frequency differences work with Fuzz. I’ll update in a few weeks

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