George , I did put my ear to the tweeter and I can hear almost complete silence - much better than class AB amp I had before. I'm not surprised since tweeter membrane has no chance to move at 500kHz.
Modern SMPS are much quieter than linear power supplies that, in reality, are very primitive noisy switchers operating at 120Hz. Modern SMPS switches at zero voltage/zero current while much ripple is much easier to filter out than 120Hz, that requires huge amount of capacitors (that produce unwanted inductance that is in series with the speakers). In spite of all capacitors linear power supply in power amps is unregulated. Because of that Jeff Rowland does not use linear power supplies at all. He uses SMPS even in preamps to lower noise floor. Benchmark replaced linear power supply in their latest DAC with SMPS lowering noise floor by 10dB.
Mapman is right - you're not sold on class d yet. I enjoy my class D amp immensely. Efficiency is not that important to me (but it should), but is always welcomed as added benefit.
Modern SMPS are much quieter than linear power supplies that, in reality, are very primitive noisy switchers operating at 120Hz. Modern SMPS switches at zero voltage/zero current while much ripple is much easier to filter out than 120Hz, that requires huge amount of capacitors (that produce unwanted inductance that is in series with the speakers). In spite of all capacitors linear power supply in power amps is unregulated. Because of that Jeff Rowland does not use linear power supplies at all. He uses SMPS even in preamps to lower noise floor. Benchmark replaced linear power supply in their latest DAC with SMPS lowering noise floor by 10dB.
Mapman is right - you're not sold on class d yet. I enjoy my class D amp immensely. Efficiency is not that important to me (but it should), but is always welcomed as added benefit.