A couple points to consider:
- 45A peak typically means peak, not peak to peak, for sine wave you know that would be 31.8A. We can assume they did base the value on sine wave, but that's just a reasonably assumption, and we could be wrong. If you want to know exactly what they mean, then you are going to have to ask them.
- It says each channel, that does not imply all channel driven simultaneously. There is no way that 1.6kVA transformer can handle 5X31.8A rms, unless the load is 2 ohm or less. Otherwise even a 30A breaker would trip if it last any longer than a few seconds.
Such kind of specs is really more hype than practical. unless the load dips to 1 to 2 ohms, the 31.8A rms is not that useful. Even for a 4 ohm load, 4X31.8A = 127.2V. We both know that amp won't have rail voltage any where near that kind of voltage.
I consider it a truly high current amp mainly because of the 1.6 kVA transformer and 100,000 uf of capacitance, and the 5X200W into 4 ohm specs, not because of the practical value of the so called high current capability. Now that's assuming Parasound's specs for this particular amp is accurate. From what I know, there is no guarantee that their specs for every products are 100% accurate.