Same schematic as 2N3055 but with BD139
https://euroelectron.blogspot.com/2019/05/pleiades-one-transistor-emitter.html
Vb=9.8V, base bias resistor 10KΩ, current through speaker 500mA. Class A operation (electrons flowing all the time). Possibly needing a bit more than 10KΩ to reduce power consumption when listening at low levels. Persons a ganged potentiometer, ie 2 potentiometers moving together, one fir volume one for optimum buas. Or perhaps even better 2 sepatate potentiometers, the user adjusting for best sound and less power consumption.
Very nice sound.
Sweet, warm, excellent: treble, mid, bass, transient response.
BD139 was kindly suggested by Mr. Sideris while visiting his electronic parts shop in the centre of Athens.
Life is interesting. A 30p transistor may send to the cleaners amplifiers costing K€.
Later addition: BD135 had been tried the day after:(br /> https://euroelectron.blogspot.com/2019/05/single-ended-bd135-vs-bd139-power.html
No comments:
Post a Comment