Boulder 850 Balanced Mono Power Amplifier Pair
Monoblocks. Overkill, right?
The use of conjoined-channel, “stereo” amplification is so ubiquitous, most folks look at two big separate mono amps and say “Nope!”
Nonetheless, the discovery and development of amplification began as a mono endeavor. Actually, if you think about it, the stereo amp is the strange bird.
An amplifier does one thing: it takes power from the wall, processes it, and then whips it up and down in big volt swings to represent the music signal fed into it. Amplifiers turn our wall power into music, and music is a wildly complex thing. They have a tough job.
When you consider that speakers in a room perform the task of re-blending the left and right signals in front of you, you can see what a massive role in the eventual stereo image that they play.
So, question: Would it be better to keep those signals separate until they get to the speakers?
You’re damn right it would. That’s why we have monoblocks and dual mono amps. Blending isn’t the amp’s best skill set — let’s leave that to the purpose-built blending machines (our “cone-and-dome monkey coffins” ;).
When two channels of amplification don’t share a power supply and don’t share a ground, in general, we get lower noise per channel. Noise is the bane of all good sound.
But we also get better instantaneous current output for each channel when we separate the supplies. Two channels sharing a power supply cap bank will pull energy potential away from the each other based on what the signal does. Yes, this is a small variable, but with a complex input like music, small variables result in real sonic changes.
The last thing I can think of to explain the use of monoblocks is power. An amp running one channel only means that both heatsinks are free for the taking. Slap a few more output devices on there why don’tcha. Let’s dissipate some energy.
Unfortunately, monoblocks are an expensive thing to experiment with. Even a visit to a local dealer can’t always give you the audio knowledge of what a jump from stereo to monoblock can do for the sound of an amp design.
If you are lucky enough to have a very flexible and very well-appointed dealer, ask sometime to hear the stereo version and the monoblock version of the same amplifier, compared to one another.
Having previously worked for an amplifier manufacturer, I’ve performed this type of comparison many times. And the results are always clear as day. Music is meant to be amplified in mono!