This is a great discussion. I used to think that if the amp doubles its power from 8 ohms to 4 ohms, it's capable of delivering a lot of current. True, this is a good sign, but there are high current amps that don't exactly follow this rule. If you are familiar with the Electron Kinetics Eagle 2 amp by the legendary John Iverson, it's rated at 125 wpc into 8 ohms and 200 wpc into 4 ohms. Yet, it's acknowledged as one of the real 'high current' amps. It can drive inefficient and difficult speaker loads with ease (such as the Apogee ribbon speakers) inspite of its relatively compact size. If you peek inside an Eagle 2 amp, you'll see some other signs of a typical 'high current' amp: a massive power transformer and two oversize electrolytic capacitors, each one the size of a beer can (80,000 mf x 2). I would also tend to agree that a heavy amp is a good sign because it usually means it has a hefty power supply. This is just my two cents worth.
