Reminder: how to tell current from an amp's specs?

I have a sinking feeling that I've been here before but, as the subject line says, how can I tell an amp's current from its published specs? 



So what do you plan to do with the current after you have a number?  It is generally not useful to know.

Let me ask it this way. I've repeatedly read that some speakers, notably Maggies, thrive on high current amps.


It really doesn't work that way. What is important is if the amp can drive the load with its rated power. If it can't obviously it will clip prematurely.

The 'current' is surprisingly small. Let's say you have 4 Ohm Maggies and you're driving them with 200 Watts. The Power formula tells you the current:
Power = Current(squared) x Resistance

Power is 200 Watts

Resistance is 4 Ohms.

The current is thus about 7 Amps. Not that much really. So if 400 Watts then 10 Amps; still not that much.

Current cannot exist without Voltage; together they are Watts.

You might want to read this:

Amplifier myths

The 'current' you read about so often with much larger numbers is actually something else! Read the article at the link.



Simple. I'm thinking about getting a new amp for my Maggies. A number of people recommend a high-current amp for them. (Some say this is a myth.) The repeated line is: "it's not the watts; it's the current." So I'm curious how people determine which amps have high current. It's that simple. I don't need a number and I don't mean to suggest that it would determine which direction I go in. It just makes me curious how people know if an amp is high current or not. (Let me add that I'm not trying to open a debate about Maggies with tubes or Class D or anything like that.)

I'll add as well that I'm a humanities professor, not an electrical engineer. I don't even understand what people mean by "power" out here (In cultural studies, we use that term in a Foucauldian sense.) Sometimes that word seems to mean watts, sometimes current, or voltage, or ....  I once set up a model train for my son. It took enormous focus for me to work through these terms, and unfortunately what little I learned is gone.


I may be completely wrong, but I've been under the impression that an amp was considered "high current" if it was able to double (or nearly so) it's output wattage every time the load resistance was halved. So, 50W into 8ohms, 100W into 4ohms, 200W into 2ohms. Many amps won't do this, some will.

Thanks to everyone! And @atmasphere , I wrote my response before seeing that you had posted your very helpful response. I think I'm getting it!