The audio power amplifier features a CFA input stage and a quasi-complementary power output stage. Ten NJW21194G are used in the output stage to produce high power output when connected particularly to low impedance loads. This is also titled Project 53 at the website.
The prototype model achieved 49.2Vrms across an 8Ω load with ±75VDC power supply rails. This is equivalent to 302.98 watts at 8Ω or 605.16 watts at 4Ω of unclipped audio power output. Higher power output is possible by increasing the power supply rails to ±85VDC and additional power output transistors to improve power dissipation.
The input stage is Current Feedback Amplifier based, chosen because of its outstanding circuit performance, wider audio frequency response and overall musical fidelity.
In real world listening with various music materials, the experience did not disappoint, considering that this is a quasi-complementary based power amplifier.
It’s difficult to distinguish the audio quality between this project to a full complementary symmetrical power output stage amplifier. However, some listeners might inconclusively perceive a subtle difference only when listening to certain specific music genre. If properly built you should be able to replicate the prototype.
26 авг 2024
