Title.
Some amplifiers are marketed with “Current of XX Ampere in each channel”. I googled it and the only thing I managed to find was some forum expert saying “Current is more important than wattage rating”. But I still don’t understand why. Ohms law is still ohms law. Doesn’t matter if you advertise one or two of the factoring numbers from the equation.
Parasound advertise their amplifiers with current rating. Does is matter and why don’t other brands do it as well?
Disclosure: I am not a EE. But as I have understood it, current capacity is aligned with an amp’s ability to to drive a speaker’s reactance throughout its impedance variations, which follow no simple Ohm’s Law calculation. In audible terms it means more powerful and controlled bass from your woofer. But I’ve heard amps with huge current ratings sound pretty poor in other respects. Krell was the first company to tout current doubling as the holy grail. But McIntosh always used their autoformers to trumpet “Full power to any load”. NAD now tells us “load invariance” is a virtue, and give their Hybrid Digital amps the same rating at all impedances….and are widely considered outstanding. The takeaway for me is don’t get hung up on these numbers. The FTC preconditioning requirement made it much tougher to give high 4 ohm ratings and caused a lot of over engineered over priced products to be marketed. You wouldn’t want an amp with less current than needed to drive your speakers, but having way more than enough doesn’t buy you anything.
NAD uses small power supplies, that is their “virtue”. Show me an amp with high dynamic range and I’ll show you an amp with an undersized power supply.
NAD Hybrid Digital amps, whether Hypex nCore, uCD, or Purifi, all use PWM power supplies that are highly efficient, unlike conventional supplies, and all their power ratings are conservative. It’s a big point for them. The era of soft clipping and +3dB headroom was the 80s, long before Class D was in vogue.