Amplifiers are the literal heart of any audio system, pumping the electrons that bring speakers to life. A great amplifier doesn't have to perform any special tricks; all it needs to do is remain composed when operating within its specifications and go about its business as transparently as possible. Recently, Monoprice introduced the Monolith 7 amplifier ($1500), the first in a new line of affordable high-performance audio products.
A revealing view of the Monolith 7.
The Monolith 7 is a rock-solid class-AB amp that delivers 200 watts per channel to all seven channels simultaneously when presented with an 8-ohm load. There's nothing particularly fancy about it—it's a black box, after all—but it's clearly well-built with a chassis and aluminum faceplate that have a high-end look and feel. It comes with a 3-year warranty.

Monoprice works with various OEMs and does not disclose who makes any given product it sells, but the provenance of this amp is already known to folks in the forums. I'll leave the discovery process to those who leave comments. Having said that, one of the cool things about the Monolith is that it's designed and built in the USA.

Features and Setup

Unless you happen to be a powerlifter, unpacking and installing the Monolith 7 is a two-person job. Despite its modest dimensions of 17" (wide) by 7" (high) by 16.5" (deep), it weighs a hefty 93 pounds, thanks in part to its dual toroidal transformers.

The all-black chassis has a thick aluminum faceplate with a recessed power button. Thump-free power-up is a welcome feature. On the back side of the amp you'll find seven RCA inputs and seven sets of speaker terminals. There's also a ground terminal, a receptacle for the power cord, and a power switch.

The RCA inputs plus the speaker terminals are evenly spaced and line up with the individual amplifier modules contained within. If you take a peek inside the amp, you'll see its design is very clean with minimal internal wiring.

The Monolith 7 does not include balanced XLR inputs, but in typical home use (short cable runs), you'll never need the 6 dB lower noise floor that balanced connections buy you. With a listed S/N ratio greater than 120 dB, it is already silent enough for home use—I never heard any inherent hiss at all.

Attaching interconnects and speaker cables to the amp was super-easy. Large white lettering clearly identifies every input, and the color-coded speaker terminals easily handled Monoprice 12-gauge speaker wire, and they can accommodate 10-gauge or 8-gauge cable. The terminals are also compatible with banana plugs.
The RCA and speaker wire connections on the Monolith 7 are well-spaced and robust.
If you want to drive a surround system and keep distortion levels low, many AVRs can't take full advantage of the speakers when all channels are driven. Distortion goes up and power per channel goes down. Adding an external amp solves that problem for AVRs equipped with preamp outputs. Moreover, if you opt to run your system with a pre/pro instead of an AVR, an external amp is a necessity.

Performance

Once it was connected to my Pioneer Elite SC-85 AVR, the Monolith 7 sounded absolutely great, and I'd gladly assign it any and all superlatives that high-end audio writers grant the amps they review. There's hardly anything to discuss here—you feed it a line-level audio signal and it delivers speaker-level audio without mucking anything up. Its frequency response is flat (20 Hz to 20 kHz, +/-0.1 dB) with no audible distortion. Both THD and IMD are below 0.03% at full rated FTC power according to Monoprice specs.

I used the Monolith 7 and SC-85 AVR over the course of two months with a variety of speaker systems. It proved to be a very potent combo, offering quite a bit more power than the AVR on its own. Most of the time I had it, the amp drove seven of the nine channels in a 5.1.4 Dolby Atmos system , which consisted of two PSB Imagine X2T towers, two XB bookshelf speakers, a XC center, and four XA elevation modules. Since it's a 9-channel system, I used the SC-85 to amplify the front pair of Atmos modules, an easy task for my AVR.

With the Monolith in charge, the PSB Imagine X speaker system came alive during action movies. The Imagine X2T tower speakers are not all that sensitive (88 dB anechoic, 90 dB in-room) but they can make good use of 200 watts of power when they are going for the gusto. The XB bookshelf and XC center have 150-watt power handling and a similar sensitivity rating—it's the sort of speaker system that rewards ample amplification.

From a performance standpoint, I found no difference between the Monolith and other more-expensive amplifiers I have auditioned in the past. When I reviewed the Imagine X as a 5.2 system a few months back, I used a $5000 Classé Sigma AMP5 —which is on long-term loan as my reference—and it offered no more power or apparent finesse than the Monolith 7. Granted, the AMP5 is much lighter and more compact than the Monolith—not to mention rack-mountable—but each AMP5 200-watt channel costs $1000 versus $215 per channel with the Monolith 7—sizeable savings for sure.

There's nothing about the Monolith's real-world performance that suggests it can't meet its published specs. Wearing earplugs, I pushed it as hard as I dared and found that the speakers reached their performance limit without straining the amp. Monoprice isn't shy about sharing detailed test results from an Audio Precision analyzer, which indicate it is a stout performer. While I wish I had access to similar measurement gear, I'm simply not equipped to verify the sort of in-depth measurements Monoprice provides here .

Even though 7-channel amps are clearly destined for use in surround systems, I was curious how the Monolith 7 would serve as a 2-channel amp. I hooked up a pair of KEF R500 towers (90 dB/W/m, 250 watts, 8 ohms) and ran 'em full-range with a variety of Tidal HiFi tunes. KEF's tower speakers shine when provided with proper power, and as I went through my music catalog, the fidelity of the amp was commendable in its transparent neutrality and the ease with which it did its job.
Conclusion

This review is short and sweet on purpose. When an amp is doing its job right, there's precious little to discuss, and that was the case with the Monolith 7. I hooked it up, plugged it in, turned it on, and it sounded great right away and up to this very moment as I type while listening to it. The amp did not ever falter, overheat, shut down, emit a humming sound, or otherwise misbehave in any way.

Another look inside the Monolith 7.

The main flaws of this amp are not really flaws per se; rather, they are concessions to making it as affordable as possible without sacrificing core performance attributes. It lacks balanced inputs, but that's one reason it is such a bargain. It's big and heavy (unlike class-D amps with switch-mode power supplies), and it requires lots of breathing room—the cover is perforated on the sides, not just on top—but there's no fan. This is not a rack-mountable amp, but it looks handsome on a shelf.

I'm a fan of Monoprice for the nearly unbeatable value the company offers in its products. The Monolith 7 is a serious piece of gear that's available at a surprisingly low price. As a result, I recommend it without reservation while looking forward to more Monolith products from Monoprice. Thanks to products like this, the cost of high performance is lower than ever.

REVIEW SYSTEM
Sources

DIY Windows 10 PC with Nvidia GTX980 HDMI 2.0 video card
Samsung UBD-K8500 UHD Blu-ray player

Amplification and Processing

Pioneer Elite SC-85 AVR
MiniDSP DDRC-88A Dirac Live processor (for subwoofer EQ)

Speakers
Surround system

PSB Imagine XT towers (2)
PSB Imagine XC center
PSB Imagine XB bookshelf speakers (2)
PSB Imagine XA Atmos modules (4)
SubSeries 200 subwoofers (2)

2-channel

KEF R500 tower speakers