Monoprice has
Monolith by Monoprice M7100X 7x90 Watts Per Channel Multi-Channel Home Theater Power Amplifier with RCA & XLR Inputs (43866) on sale for $649.99 - 50% with promo code
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$324.99.
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vid1900 for sharing this deal.
Details:
- 7-channel Class AB power amplifier
- 90W per channel into 8 ohms, all channels driven
- THD < 0.02% with SNR > -100 dB
- Unbalanced RCA and XLR inputs
- 3RU height
Top Comments
If you want to see how a bunch of the new receivers only put out ~30 watts when they go into a secret 'limp mode' with no indication that you are not getting the 135wpc you paid for......
Even if you forget and leave the internal amps on, the heatsink fans will never come on because they are not actually under load.
https://www.audioscienc
The 30wpc that you are currently getting from the receiver seems loud, but you are missing out on the dynamic peaks that can be 100w, even on moderate volume movie watching.
Community Reviews
This Monolith 7-channel amp is mainly pitched as a clean-power upgrade for home theater setups that need extra channels or more headroom, especially with receivers that can process more than they can amplify. It is described as running cool, helping the AVR work less, and making a noticeable difference in dynamics or low-volume clarity in some systems. The main cautions are a reported faint hum on some units, a two-prong power cord with no ground, and the possibility that many normal listening setups will not sound much different from a decent receiver. It is a practical fit when you need external amplification more than raw loudness.
Common Questions (6)
Some units reportedly have a faint hum that does not go away, while others are silent even with high-sensitivity speakers. Power draw reports also vary: one measurement showed about 38W in standby and about 43W during Blu-ray playback with no speakers connected, so a power strip may be the safest way to fully cut power.
Yes, the Denon 4300 can feed it through pre-outs and amp assign, but it does not have a dedicated preamp mode, so its internal amps still draw power. The Denon 3800 does have dedicated independent preamp mode, which makes it a better match if you want to offload channels and reduce heat or power use.
For many normal-use setups, the difference can be small or hard to hear, especially if the AVR already drives the speakers comfortably. The main gains are more headroom, better dynamics at higher levels, and less strain on the receiver rather than a guaranteed night-and-day sound change.
For typical movie listening at comfortably loud levels, 90WPC is usually enough, especially with reasonably sensitive speakers and a normal-sized room. Several comments note that 30WPC is already quite loud in real-world use, and that the bigger benefit of an external amp is extra headroom for dynamic peaks rather than a dramatic loudness increase.
Yes, if you need external amplification for extra processed channels or want room to grow beyond a 9-channel AVR, it can be a practical buy. It is also useful when you want to move some channels off the AVR to reduce heat and preserve headroom for future expansion.
It can lock into limp mode if it is asked to deliver more than 30WPC into 4 ohms, and there is no clear indicator on the unit when that happens. With 8-ohm speakers it may never trigger, and the easiest check is to compare sound at normal volume before and after switching the AVR to 4-ohm mode or measure output with a watt meter.
AI-generated summary based on comments from the community. Updated ago
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188 Comments
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I've setup several of these PAC units & no one has ever pointed out, oh no limp mode issue kicked in!
One recent was the RZ30(& compared to RZ70), a 9 channel SVS Prime/Ultras & 1 sub in a medium size environment.
We pushed it way over normal/average levels.
If limp mode kicked in, none of us noticed.
At normal/ average levels, it was a very capable unit.
As a matter of fact, other than those extremely high levels, it held up pretty well vs the RZ70.
Especially when you consider the price difference!
Imo I would invest the $325 in DLBC, it improves the sound better than power.
I have the LSIM in my two setups. I know your speakers. I have the five channel in my family room powering my 704, 703, and two xt90 n my rear. Is it as good at the monolith x, No. But it will be way better than what you have and that is probably enough. I have the 11x in my HT, but that is driving the 705, 706, 702, 80fx, reserve 900, r900.
Obviously, the amplifier prevents clipping, but much of that depends on how loud you listen to it.
I tried to pair them with a of the top-of-the-line (well, maybe a step or two down, but still very expensive) Yamaha Aventage amp, and they sounded OK in stereo mode, but trying to run full surround sound with make the amp involuntarily cut output or even shut off entirely. For context, I don't listen to music at very high volumes—even reference volume (85db) feels very loud to me. So it truly is a quirk of speaker design that made these old speakers kill amps. As I understand it, it's principally a result of crossover architecture.
Anyway, if in the exceedingly unlikely event you happen to have speakers like that and are tired of killing amps and receivers, this Monolith should solve your problem (assuming it has an adequate power supply).
(FWIW, I completely got out of passive speakers when I learned how good active designs have gotten. My main setup now is Kali studio monitors with room correction. They're way smaller, not power hogs, and sound better than anything I've tried before. And they're pretty cheap.)
The performance is degraded to some degree due to the amp not being able to provide the power(current) needed for high SPL dynamic peaks.
The heat generated could shorten the lifespan but I would not think of it as killing the amps.
If you drive to very high levels the amps can and will go into protect and shut down.
I have the LSIM in my two setups. I know your speakers. I have the five channel in my family room powering my 704, 703, and two xt90 n my rear. Is it as good at the monolith x, No. But it will be way better than what you have and that is probably enough. I have the 11x in my HT, but that is driving the 705, 706, 702, 80fx, reserve 900, r900.
Obviously, the amplifier prevents clipping, but much of that depends on how loud you listen to it.
Some do have limiters for clipping typically just 'pro' amps, most just go into protect by shutting down or greatly reducing the output level when the current draw is to high or the temperature is to high but by then you may already be in hard clipping.
There will be little improvement in dynamics. The amp does not produce more power except when the current draw is high. Then in those areas at maximum volume you get a couple db of extra output. Likely not meaningful in most cases & in the ones who do benefit just get an actual high power amp, not 90-135watts.
If you want and value 'dynamics' (especially when in larger spaces) include subwoofers, possibly larger speakers and amps with real high power output in the 250-600+watt channel range. Then you will likely never run into clipping and you maximize the 'dynamic' capability of almost any speaker since that more output that most can handle.
TBH XLRs are even way less of a benefit than power.
That's if it's even a true balanced signal, not all are.
The two prong power cord would probably be a bigger issue/concern.
You pointed to one reason, the run is usually very short.
Another is technically the XLR should extend from external amp to speakers, most don't.
They do this with subwoofers for a reason, it is also a "speaker" after all.
Personally I'd rather have those XLRs added on AVRs.
Just get some decent rated ones on Amazon like CableDirect, GEARit, monoprice is there also.
If you only need 2 channels, this is the unit you need and is $199 after the SHOP50 code:
https://www.monoprice.c
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Speak of reality, out of curiosity, at what point did you hear this limp mode kick in on the 505?
What were the parameters?
Im not sure I would call things like Atmos/DTS:X, Dirac, Auro 3d, virtual X, HDMI 2.1,etc "junk"!
I do agree on eternal amps though..... buy once, cry once.
Especially since good ones easily outperform internal power supplies!
Like you I'm using the 3800 as a pre pro, it offers all the tech current PAC units offer & then some!
Speak of reality, out of curiosity, at what point did you hear this limp mode kick in on the 505?
What were the parameters?
My buddy at the audio shop told me that a customer had traded the unit in because of the limp mode. He knew I had a bunch of high current amps in my system; so I would be immune to the problem.
It fixed the eARC problem of my old receiver
You can still use a 30 year old amp to it's fullest capabilities, but you sure are not going to use a 30 year old surround receiver.
You should try to hook it up and see if you can hear that limp mode issue.
I think you mean outdated rather than junk.
Keep in mind it's only junk/outdated if you don't use it or need it anymore.
The irony here is that we have the advancements of Atmos/X & 4k/HDR and many choose to stream & a soundbar!
Current commercial displays can't even take full advantage of 4k & we're talking 8K now!
I can tell you that "Atmos" is really only advantageous if done properly.
If it's not(most aren't) the legacy algorithms can be very comparable. Especially with streaming content!
As tech and formats change in AVR's, clean power never becomes outdated.
Buy one of these once, and a nice AVR/pre ever 7-10 years, and you're set for life!
I would say if you want actual "audio reality".
You should try to hook it up and see if you can hear that limp mode issue.
Either they don't accept Banana Jacks, or they are spaced incorrectly for plugging in the jack pair.
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FYI those internal amps continue to draw power while using pre outs, they do not turn off(ie preamp mode).
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