Several designs in our product range require matched transistor pairs for optimum performance.
Devices used in our products:-
Suitable thru-holes devices include: 2SC3381, 2SC1583, MAT-02, LM394, SSM2210, THAT3xx, however some of these devices are now hard to source.
The Dual Sub-Assemblies comprise a dual-matched SMT transistor pair mounted on a 6-pin DIP carrier. These can be used in place of the integrated circuit devices as shown above .
It is also possible in some situations to use your own hand-matched devices. When doing so, you should use high-gain, low-noise audio transistors and achieve a Vbe matching within at least 2mV and, ideally, 0.2mV. The transistors are mounted as shown here
NB:you need to verify the footprint of the devices you are using to ensure they are mounted correctly.
NB: Our Dual Sub-Assemblies use a 6-pin footprint but are often placed onto an 8-pin DIP. Refer to this diagram for correct positioning.
Original Kit Version