Extremely quiet SMPS operating at MHz frequencies and utilizing zero voltage zero current switching. Such power supplies are not only extremely quiet but also have line/load regulation. You can find them in all newest Jeff Rowland amps (including class AB). He also uses SPMS in preamps (Capri) to keep noise low.
Benchmark got rid of linear power supply, used in DAC1, replacing it with SMPS in DAC2, resulting in 10dB lower noise floor. Their brand new ABH2 class AB power amp also has SMPS resulting in S/N=132dB.
Also, in addition to improvements in discrete semiconductors integrated components like OpAmp, Buffers, Instrumentation Amps, etc. got much better.
Many amplifiers are built now using surface mount components. It is significant quality improvement since SMT process is very repeatable making country of origin pretty much irrelevant (that way Apple delivers high quality products, all made in China).
Benchmark got rid of linear power supply, used in DAC1, replacing it with SMPS in DAC2, resulting in 10dB lower noise floor. Their brand new ABH2 class AB power amp also has SMPS resulting in S/N=132dB.
Also, in addition to improvements in discrete semiconductors integrated components like OpAmp, Buffers, Instrumentation Amps, etc. got much better.
Many amplifiers are built now using surface mount components. It is significant quality improvement since SMT process is very repeatable making country of origin pretty much irrelevant (that way Apple delivers high quality products, all made in China).