Mcintosh 2301 tube amplifier, how much power used from the wall?

The specs show it can draw 5.5A at 120VAC, or 660 watts. Of course, some of that power is used to drive the speakers - only some of it is wasted as heat.

I don't think the specs reflect what really happens. If it is that much it will heater room like a portable heater set to low Times two.

The only way to do this is to measure it from the wall.

What reaches the speaker is a minor part of the equation.

For example, the 600 W Mac amplifier only uses 60 to 70 watts when turned up very loud. 

I sniped this from ChatGPT:

The amplifier's power consumption varies depending on its operating conditions. Under typical usage, with normal audio signals and average volume levels, the MC2301 consumes around 800 watts of power per channel. Since it is a stereo amplifier, the total power consumption for both channels combined would be approximately 1600 watts.

If chatgbt is correct, that's absolutely horrifying.

That means this amp is equivalent to a full blown portable heating unit running continuously, and the heating units are about 1800 W on the high mode.

We are doomed!  Beware of AI

If the amp draws 5.5 amps at 120 volts then 660 watts is the most that can be converted to heat (energy is always conserved). That can mean, for example, you will need an additional 2,250 btu/hr for a room air conditioner just to remove the heat from the amplifier.

To get an exact number is tougher to calculate. The amp at idle will draw the bias current only, and that can be a value which is a fraction of the 40W plate dissipation. When the signal is going through the amp, the current is fluctuating and rarely goes to max plate current, so the overall heat dissipation can only be determined by monitoring the current draw over a given period of time (say, an hour). Then you can get a more precise number. If all you want to do is size an air conditioner then just use the rated amp draw, or use the nominal amperage of the mains fuse.

Kill-a-watt

@gs5556 +1

Mike

@gs5556

The info you have provided on energy use and heat generation is alarming. A human body generates about 300 BTUs just sitting on the couch. Generating 2400 BTUs per hour is close to eight people in a room and that generates a lot of heat.

Would be nice to get the actual usage measurements if anyone can do it from eight from a tube amplifier

99.9% of the current that comes into the amp ends up as heat in the room.

The good news is that the current drawn is always well below the nameplate. For example, my Decware ZMA has a max current of 3 amps at 120 v is 360W. Measured power is about 160 watts.

I have an Ayon 6C33C amp with a measured power of about 400 watts.

The power out to the speakers is relatively irrelevant to what power is consumed. If the amp is class A, it will consume the same power with volume at zero as with volume at full. Ignore the posts of people trying to relate power out watts to power in watts. I have a 4 wpc amp that consumes 200 watts.

The tubes are inside this amp which is a good sign. If they were too hot, then they couldn’t be inside. To get the high power this amp boasts, it is obviously push pull which means less heat.

Audiophiles generally don’t have the capacity to measure current from the wall. Ask for someone with a PS Audio power supply. they read instantaneous output so plug only the amp into it and you’ll get the amp load. or just measure the entire system and DAC plus streamer is probably 20W or so. Don’t include the TV if that is plugged in.

I’d guess this amp is 250 to 300 W.

Jerry

PS  Great to see ChatGPT get this one totally wrong.

@carlsbad2

Thanks for a great reply. Have you ever done biamping with tubes on the top drivers and ss for bass drivers? big challenge is finding a crossover device, and then hearing that if you use amplifiers from the same manufacturer, tube and ss, you can do it without this device. I don’t think this is really done very much but many people do it, it’s tough to find these people

I haven't done biamping and don't generallly think it is a good idea.  I have no problem with trying it but most try it and move back.

Your amp has plenty of power for just about any speaker.

The "rule of thumb" that you need an external crossover is not correct.  The internal crossovers will so the same job with 2 amps that they do with one. All you need is the ability to adjust levels to balance the 2 amps.  this can be done with a passive pre or just a volume control device on whichever amp needs to be turned down.

Volume control device? What would be an example of this?

Thank you