Monday, April 17, 2023

Doubling the loudness of the Pleiades 2N3053 single transistor minimum negative feedback audio power amplifier

Audio transformers are amazing sounding fantastic creatures. Collector to base single biasing resistor changed from 100KOhms to 200KOhms. Sound is much more open, bigger, deep with more detail, louder. Collector current is just 5mA, am I dreaming? It makes sense since supply voltage is 12V, therefore Vb:Ic=12V:5mA=2.4KOhms, the output transformer is 2.5KOhm to 8 Ohms so impedance is matched, hence no energy reflected back from the speaker to the transistor. Signal path: Time - Alan Parsons Project - Sony CD Walkman 300ohms line out - Pleiades 2N3053 with Sowter SK05s - KEF CS5 constructor series (tweeter connected in phase since the day before yesterday!)

No comments:

Post a Comment