3 and 4 is same as 1 and 2 - greater dynamic range requires good current delivery and low noise.
Instruments won't have natural timbre thru noisy gear that compresses dynamics.
5 - Imaging is related to noise as well but also to crosstalk, often thru common power supply. Power amp supplies are most likely without line and load regulation with inductive capacitors. Separate power supplies for each channel or even separated amplifiers (monoblocks) will reduce crosstalk.
Jeff Rowland started using sophisticated switching power supplies in latest model 625 (class AB power amp). It switches at 1MHz (easy to filter out) with zero voltage/ zero current switching. It delivers clean voltage that is line and load regulated (not to mention efficiency).
Linear power supply is also a switcher operating at 120Hz where switching appears in worst possible place - at maximum AC voltage. Current is supplied from mains in sharp narrow spikes. Width of these spikes changes with load (switcher's definition). 120Hz ripple is difficult to filter out and requires a lot capacitors. Transformer has to be huge for good performance. In comparison same power transformer operating at 100kHz can be 10x smaller. That's the future in my opinion. Jeff Rowland already uses switching supplies to obtain low noise in preamps (Capri) where efficiency is secondary issue.
Instruments won't have natural timbre thru noisy gear that compresses dynamics.
5 - Imaging is related to noise as well but also to crosstalk, often thru common power supply. Power amp supplies are most likely without line and load regulation with inductive capacitors. Separate power supplies for each channel or even separated amplifiers (monoblocks) will reduce crosstalk.
Jeff Rowland started using sophisticated switching power supplies in latest model 625 (class AB power amp). It switches at 1MHz (easy to filter out) with zero voltage/ zero current switching. It delivers clean voltage that is line and load regulated (not to mention efficiency).
Linear power supply is also a switcher operating at 120Hz where switching appears in worst possible place - at maximum AC voltage. Current is supplied from mains in sharp narrow spikes. Width of these spikes changes with load (switcher's definition). 120Hz ripple is difficult to filter out and requires a lot capacitors. Transformer has to be huge for good performance. In comparison same power transformer operating at 100kHz can be 10x smaller. That's the future in my opinion. Jeff Rowland already uses switching supplies to obtain low noise in preamps (Capri) where efficiency is secondary issue.