NKT275 Transistor Pinout, Equivalent, Features, Uses and Other Useful Info

This post describes NKT275 transistor pinout, equivalent, features, uses and other useful information about this TO-1 package PNP germanium transistor.


NKT275 Transistor Pinout, Equivalent, Features, Uses 


Features / Technical Specifications

  • Package Type: TO-1
  • Transistor Type: PNP
  • Max Collector Current(IC):  0.25A
  • Max Collector-Emitter Voltage (VCE):  15V
  • Max Collector-Base Voltage (VCB):  15V
  • Max Emitter-Base Voltage (VEBO):  5V
  • Max Collector Dissipation (Pc): 200 Milliwatt
  • Max Transition Frequency (fT): 0.5 MHz
  • Minimum & Maximum DC Current Gain (hFE): 70 – 130
  • Max Storage & Operating temperature: 90 Centigrade


NKT275 Transistor Explained / Description

NKT275 is an old germanium transistor that was available around 1960’s. In that time it was a common transistor like AC128. As the technology of transistors progresses, newer silicon transistors are being replaced by these older transistors which are more accurate, reliable and good performers as compare to these older germanium transistors and hence the companies that were making these transistors gradually discontinued their manufacturing.

But some of these transistors are still well known by some fuzz face makers and users. The fuzz face is an analog device connected with the guitar and provides different tones or effects in guitar sound. The fuzz face circuit is easy to build and required only few components but its main components are the PNP germanium transistors, however, these days you will also find fuzz face devices that uses silicon transistors but people still like the of ones that use germanium transistors most likely AC128 and NKT275. As mentioned above that the NKT275 and AC128 are not manufactured anymore but they can still be found with some electronic sellers which stock up old components.


Where We Can Use it & How to Use

The NKT275 transistors are mostly used in fuzz face devices but they can also be used to replace other similar transistors. The procedure of using these transistors is same as we use any other PNP transistor.


Replacement and Equivalent

Silicon material alternative for NKT275 are BC337, 2N3109, 2N2905,  2N3107, 2N2905 , 2N4032

Alternative for using in Fuzz Face are AC128, BC108, BC183, BC109, CV7005.



Old electronic appliances

Old audio appliances

Old radios

Old televisions

Fuzz Face Circuits

Old Audio appliances


Safe Operating Guidelines / Absolute Maximum Ratings

To use this transistor safely do not operate it on its absolute maximum ratings and always operate it 20% below from its maximum ratings. The max collector current is 250mA therefore do not drive load of more than 200mA. The maximum collector to emitter voltage is 15V therefore do not drive load of more than 12V. Use a suitable heatsink with the transistor if required and always store or operate the transistor under 90°C.



Datasheet not available.

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