One P12 for a pair of monoblocks

I’ve had a P12 since February. It is hot where I live so its fans are always on.

To keep from hearing them, I have it outside the listening room, feeding outlets inside. Once I close the door, I can’t hear my P12 working.

It feeds my Marantz SACD player, BHK preamp, DS DAC, Clearaudio turntable, and other things on my rack.

It also feeds my two mono amplifiers.

Those are a pair of Emotiva XPA-1 Gen 2.

They are switched so that their first 60W are in Class A.

As a result, the continuous power draw on my P12 is high. This is when I first switch everything on.

And this is half an hour later when the amps have reached their normal (hot) operating temperatures.

My speakers are 91dB/W/m sensitive. I monitor my P12 when I listen loud and the needle hardly ever climbs any higher. Perhaps its because I don’t use up more than the 60 Class A watts of my amps.

I acknowledge this isn’t ideal and a P20 would certainly be more appropriate but my P12 has been working well. Aside from the fan, it makes no other noises. I’ve been using it this way for several months and it has never shut off by itself. Not once.

After that long intro, my question is will I have a higher or a lower power draw when I upgrade the Emotiva amps to a pair of BHK300’s?


In my world the dial is either in the green or the red - you’re in the green so that means keep on truckin’

I suspect the BHK might give you slightly more green to play with, but I’m not certain of that. I’d also be plugging the amps directly into the wall and see if it’s worth sucking all that green out of the P12 dial.

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Beautiful setup! Brodric’s right, with the 300s you’ll have some more green to play with. I just ran a quick test in our listening room and in idle, the monos are only using about 280-300w. I then cranked it louder than I would ever listen (BHK pre 50), and I think I saw it peak around 360.


According to the review quoted below, they draw 180 watts at idle.
Times 2 is 360 watts. So about 60 watts more then a pair of BHK 300s at idle.

“With 60 watts of Class A power, that means 180 watts of power are dissipated as heat when the amp is idle. Leaving the XPA-1in Class A mode at idle for an hour bears this out, as the amps will become quite warm.”

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Thanks, @Brodric. The highest continuous power draw I’ve recorded on my P12 was this.

That was with my two Emotiva amps and this beast.

All three amplifiers were in Class A mode, and to my ears, they did sound better plugged into the P12 as opposed to directly into the wall outlet. And I have dedicated outlets that go straight to the home circuit breaker panel.

Maybe it’s because the quality of the mains voltage in my part of the world is lousy. Haha… :smiley:

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I would suggest, if you can hear your P12, either it has an issue, or, is being pushed too hard. Looks to be working too hard to me.
Good luck, nice looking speakers.

Thanks, @jamesh. I’m slowly moving from an all Emotiva setup to an all PS Audio setup. My previous preamp was their XSP-1 Gen 2. I bought it because it was the least expensive preamp that operated in dual-differential mode all throughout. No conversion to single-ended. I prefer that so I can run balanced cables to the amps near the speakers. But now I have the BHK preamp which sounds night-and-day better.

Thanks for the info regarding the power draw of the BHK300 pair. They rank a whole lot higher on my upgrade priority list than a P20, and it seems my P12 will be able to power them nicely.

Thanks, @st50maint. That review was one of the reasons why I bought those amplifiers.

Also, the 180W idling power consumption in Class A seems accurate. When I switch both amps to Class AB, my P12 says the total power draw drops from 650W down to 250W. The 400W difference is for both amps. 200W per amp. Close enough to the 180W the article mentions.

Thanks, @kylemillsap. I only hear the fans on my P12 and nothing else. No weird ticks or buzzes. Without air conditioning, the indoor ambient temperature in my part of the world is 90 degrees Fahrenheit with a relative humidity of 80%, so its probably normal for its fans to be on.

About something working too hard, while it’s easy to tell if an amplifier or speaker is (it starts to sound bad), my opinion of products that supply power to other devices is a bit different. For me, they should be able to deliver their rated output continuously, without any issues. Otherwise, the manufacturer may be trying to pull a fast one.

For example, some of my friends own portable battery banks intended to charge mobile phones. I borrowed a brand new one and charged it until its indicator read 100%. “10,000mAh” is printed on the cover, which should be enough to charge the 3,500mAh battery in my phone at least twice but sadly, it can’t. It will only charge my phone up to 70% before it dies. But at $5, which is one one-thousanth of the cost of my P12, I didn’t really mind. Plus I only borrowed, not bought it. Haha… :smiley:

On the other hand, the PS Audio website says the maximum continuous load of the 220V P12 is 1,200VA. That’s what I will expect, given it’s high price and PS Audio’s excellent reputation. Not surprisingly, that’s what I get. I posted a photo above that shows my P12 delivering 953W. It did so continuously, without complaint. No hums or buzzes. Just the fans spinning. Also, the exposed heat sink on top never got too hot to touch. At no time did I ever get the impression that my P12 was working too hard. PS Audio’s specifications are, as expected, honest. This makes me very happy.

Because of this, I will (funds willing) upgrade my Emotivas to the BHK300 pair, fully confident that my P12 will be able to supply them with enough regenerated power to make my neighbors complain. Haha… :smiley:

I had a P12, fans never turned on. I live in Los Angeles, where ambient temperature without ac can be 110. 95 is a regular occurrence.

Headroom is not a luxury in my opinion. I’d get a P20. As a matter of fact, I did. I’m running DSD, DMP, BHK300s, BHK pre, two 900watt subwoofers, and Aries G2.

I had a P12 for a couple months. I thought the fans never turned on but when I went right up to it, I could feel a slight rush of air and hear the fan working. But I had to be within an inch or two.

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Strange. The ONLY way I can hear the fans on my P12 is to put an ear within two inches of it, and with no other sounds in the room.