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expiredvid1900 posted Jul 27, 2026 7:44 PM

Monoprice Monolith M2100X 2x90 W/Ch Home Theater Power Amplifier

$200

$400

50% off
+ Free S&Hat Monoprice
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Deal Details
Monoprice has Monoprice Monolith M2100X 2x90 Watts Per Channel Stereo Home Theater Power Amplifier (43863) for $399.99 - 50% off w/ promo code MOVE50 in cart = $199.99. Shipping is free.

Thanks to Community Member vid1900 for finding this deal.

Features:
  • 2 Channels of Amplification
  • 90 Watts Per Channel into 8 ohms
  • Unbalanced RCA Inputs
  • XLR Inputs
  • 3RU Height
  • Class AB Amplification
  • 3 Year Replacement Warranty

Editor's Notes

Written by johnny_miller | Staff
  • About this deal:
    • Our research indicates this offer is $120 lower (37.5% savings) than the next best price from a reputable merchant at the time of this post.
    • This offer matches a recent Frontpage Deal.
    • Please see the original post for additional details & give the forum comments a read for helpful discussion.
  • About this product:
    • Rating of 4.7/5 from Monoprice customer reviews.

Original Post

Written by vid1900
Community Notes
About the Poster
Deal Details
Community Notes
About the Poster
Monoprice has Monoprice Monolith M2100X 2x90 Watts Per Channel Stereo Home Theater Power Amplifier (43863) for $399.99 - 50% off w/ promo code MOVE50 in cart = $199.99. Shipping is free.

Thanks to Community Member vid1900 for finding this deal.

Features:
  • 2 Channels of Amplification
  • 90 Watts Per Channel into 8 ohms
  • Unbalanced RCA Inputs
  • XLR Inputs
  • 3RU Height
  • Class AB Amplification
  • 3 Year Replacement Warranty

Editor's Notes

Written by johnny_miller | Staff
  • About this deal:
    • Our research indicates this offer is $120 lower (37.5% savings) than the next best price from a reputable merchant at the time of this post.
    • This offer matches a recent Frontpage Deal.
    • Please see the original post for additional details & give the forum comments a read for helpful discussion.
  • About this product:
    • Rating of 4.7/5 from Monoprice customer reviews.

Original Post

Written by vid1900

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54 Comments

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Pro
Jul 29, 2026 8:09 PM
15.1K Comments
Joined Aug 2010
turnne
Pro
Jul 29, 2026 8:09 PM
15.1K Comments
Quote from apepi1337 :
Do you have a recommendation? I only run this set up in 3.1, glorified soundbar or 2.1 when listening to music.
if you were not in a hurry I would see if this one came around again for $325
https://slickdeals.net/f/19715778-monolith-7-ch-amp-90-135wpc-fs-325?src=SiteSearch

More channels than you need...but definitely has more if you want to grow and makes the price per channel much better
This should also be 4 ohm capable and get you more performance than the RZ30..or frankly any sub $1200 ish AVR
1
Original Poster
Pro
Jul 29, 2026 11:26 PM
3.3K Comments
Joined Sep 2016
vid1900
Original Poster
Pro
Jul 29, 2026 11:26 PM
3.3K Comments

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Quote from apepi1337 :
Will this be an upgrade on an Onkyo RZ-30?
A huge upgrade.

The rz30 only puts out 36 watts per channel into a 4 ohm speaker.

The Monolith puts 135 watts per channel into a 4 ohm speaker.

All those extra watts gives you lots of clean headroom for big dynamic swings.

https://www.audiosciencereview.co...iew.71594/
3
Jul 29, 2026 11:30 PM
3.2K Comments
Joined Nov 2007
XDeckerJul 29, 2026 11:30 PM
3.2K Comments
Quote from apepi1337 :
I currently have the RZ30 pushing Martin Logan Foundation C2's and it just seems disappointing especially at louder levels. I am cheap and want better sound. The RZ30 is new so I do not want to buy the RZ70.
See my comment about my aventage.

Granted, my aventage is an older model, but I had to turn on "low impedance" mode in order to power my elac ub5s, which are 4 ohm. AI thinks that that mode added extra protection against overcurrent and that was what was holding my speakers back (the ub5 gen 1 are notoriously power hungry).

It also kept mentioning how the damping factor on the m2100x is vastly superior to the damping factor on my avr. Not sure EXACTLY how or why this improves sound quality, but this amp just sounds WAY better than my Yamaha AVR as a power amp.

I swear to you… if you can still get this for $200, it's worth the cost easily. You won't regret it.
Jul 29, 2026 11:37 PM
3.2K Comments
Joined Nov 2007
XDeckerJul 29, 2026 11:37 PM
3.2K Comments
Quote from vid1900 :
A huge upgrade.

The rz30 only puts out 36 watts per channel into a 4 ohm speaker.

The Monolith puts 135 watts per channel into a 4 ohm speaker.

All those extra watts gives you lots of clean headroom for big dynamic swings.

https://www.audiosciencereview.co...iew.71594/
The audioholics review of the 2100x seemed to imply that the wattage is also a CONSERVATIVE rating. Something about other amps when they talk about wattage it's on a different part of the curve to make the #s look better….
Original Poster
Pro
Jul 29, 2026 11:51 PM
3.3K Comments
Joined Sep 2016
vid1900
Original Poster
Pro
Jul 29, 2026 11:51 PM
3.3K Comments

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Quote from XDecker :
The audioholics review of the 2100x seemed to imply that the wattage is also a CONSERVATIVE rating. Something about other amps when they talk about wattage it's on a different part of the curve to make the #s look better….
Yeah, the CEA 2006 Dynamic Power rating for the M2100 into 4 ohms is 245 watts per channel.

I like when manufacturers conservatively rate their products; rather than give some pie-in-the-sky numbers that crap out on the test bench.
1
Jul 30, 2026 4:22 AM
13.1K Comments
Joined Jul 2010

This comment has been rated as unhelpful by Slickdeals users.

Jul 31, 2026 7:35 PM
58 Comments
Joined May 2018
KeyOfTruthJul 31, 2026 7:35 PM
58 Comments
I don't see any volume control or remote so I assume some additional hardware such as a dac is required between the TV and this amplifier?

Also, what would be the most cost effective way to add an active amp to this setup?

Would this be a worthwhile upgrade from the cheap $200 Sony STRDH190 receiver? I have two JBL 570 floor standing speakers I absolutely love and I fear I may have cheaped out on the receiver a little too much.
1

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Aug 1, 2026 12:04 AM
13.1K Comments
Joined Jul 2010
supermanrobAug 1, 2026 12:04 AM
13.1K Comments
Quote from KeyOfTruth :
I don't see any volume control or remote so I assume some additional hardware such as a dac is required between the TV and this amplifier? Also, what would be the most cost effective way to add an active amp to this setup?Would this be a worthwhile upgrade from the cheap $200 Sony STRDH190 receiver? I have two JBL 570 floor standing speakers I absolutely love and I fear I may have cheaped out on the receiver a little too much.
I would recommend just looking for a private owner sale on a slightly older AVR.

With so many people switching to soundbars, you can find really good deals on older quality AVRs ime.

Nothing fancy needed for 2 channel and switching sound signatures will likely help also.
Last edited by supermanrob August 1, 2026 at 06:24 AM.
2
Original Poster
Pro
Aug 1, 2026 4:28 AM
3.3K Comments
Joined Sep 2016
vid1900
Original Poster
Pro
Aug 1, 2026 4:28 AM
3.3K Comments

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Quote from KeyOfTruth :
I don't see any volume control or remote so I assume some additional hardware such as a dac is required between the TV and this amplifier?
Correct. This is just an amp, so you need something to control volume (and decode the digital signals); namely a Pre-amp.

Quote from KeyOfTruth :
Also, what would be the most cost effective way to add an active amp to this setup?
Your STRDH190 has a pre-amp output on channel 4. You would hook that output, to the input on the Monolith.

Quote from KeyOfTruth :
Would this be a worthwhile upgrade from the cheap $200 Sony STRDH190 receiver? I have two JBL 570 floor standing speakers I absolutely love and I fear I may have cheaped out on the receiver a little too much.
Yes, the Monolith would be a huge upgrade amplifier wise, but would still require your Sony as the pre-amp.

Your JBLs are 6 ohm speakers, so they would not put any strain on the 4ohm rated Monolith.

Later in life, if you ever get a new receiver, you would then use the Monolith with it.

Receivers quickly become obsolete as new digital formats come out every couple of years - but quality amplifiers never become obsolete.

You still see those vintage 70s amps with their giant VU meters on the front, connected to the receivers of today. Not many tech products have half century lifespans besides amplifiers.
Last edited by vid1900 July 31, 2026 at 09:55 PM.
1
Aug 2, 2026 2:22 AM
128 Comments
Joined Nov 2015
iContangoAug 2, 2026 2:22 AM
128 Comments
This or two Fosi v3 monos... paired with a WiiM Ultra and a pair of Kef Q Concerto Meta speakers.
Original Poster
Pro
Aug 2, 2026 4:10 AM
3.3K Comments
Joined Sep 2016
vid1900
Original Poster
Pro
Aug 2, 2026 4:10 AM
3.3K Comments
Quote from iContango :
This or two Fosi v3 monos... paired with a WiiM Ultra and a pair of Kef Q Concerto Meta speakers.
Fosi are good amps, as long as you get the bigger 48v power supplies.

No 12v turn-on or xlr inputs though, and the Monolith delivers quite a bit more power in the CEA 2006 tests.
1
Aug 2, 2026 2:26 PM
13.1K Comments
Joined Jul 2010
supermanrobAug 2, 2026 2:26 PM
13.1K Comments
Quote from iContango :
This or two Fosi v3 monos... paired with a WiiM Ultra and a pair of Kef Q Concerto Meta speakers.
I would go least expensive.
In real world use, you really wouldn't hear a difference unless maybe you listen at rock concert levels ime.

In that scenario, personally I'd stick to the smaller footprint.
The listed benefits on this aren't really a sonic benefit ime.
Last edited by supermanrob August 2, 2026 at 10:01 AM.
4
Pro
Aug 2, 2026 2:59 PM
3.2K Comments
Joined Sep 2011
E4300
Pro
Aug 2, 2026 2:59 PM
3.2K Comments
Quote from XDecker :
See my comment about my aventage.

Granted, my aventage is an older model, but I had to turn on "low impedance" mode in order to power my elac ub5s, which are 4 ohm. AI thinks that that mode added extra protection against overcurrent and that was what was holding my speakers back (the ub5 gen 1 are notoriously power hungry).

It also kept mentioning how the damping factor on the m2100x is vastly superior to the damping factor on my avr. Not sure EXACTLY how or why this improves sound quality, but this amp just sounds WAY better than my Yamaha AVR as a power amp.

I swear to you… if you can still get this for $200, it's worth the cost easily. You won't regret it.
Most AVRs drop the main supply rail voltage when engaging low impedance mode. This allows the receiver to meet UL cert without overheating. Old school stuffs like my SX-1250 (160W RMS into the full audio bandwidth) don't need to switch to 4 ohm mode. I have no problem identifying the SX-1250 vs modern receivers, even with my old ears.

Get a good sound processor and pre-amp. Cheap processors add resistors to the speaker's outputs and call them pre-amp outs. Use one or more quality 2 ch amplifiers to power the speakers.
1
Aug 3, 2026 1:39 PM
3.2K Comments
Joined Nov 2007
XDeckerAug 3, 2026 1:39 PM
3.2K Comments
Quote from E4300 :

Most AVRs drop the main supply rail voltage when engaging low impedance mode. This allows the receiver to meet UL cert without overheating. Old school stuffs like my SX-1250 (160W RMS into the full audio bandwidth) don't need to switch to 4 ohm mode. I have no problem identifying the SX-1250 vs modern receivers, even with my old ears.

Get a good sound processor and pre-amp. Cheap processors add resistors to the speaker's outputs and call them pre-amp outs. Use one or more quality 2 ch amplifiers to power the speakers.
I've already bought the M2100x and it's great for the cost- it was a HUGE improvement over using my Aventage AVR as a power amp. I am feeding the M2100x through a Fosi ZD3 DAC using the XLRs (even though the XLRs on the M2100X are unblanced).

I gave up on having a full AVR setup in my living room due to the open floor plan - the wife didn't want speakers placed in various places. I'm running a JBL Bar 1300X for video/HTR sound and am using the ZD3/M2100X for 2 channel music.

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Aug 3, 2026 2:27 PM
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Joined Nov 2007
XDeckerAug 3, 2026 2:27 PM
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Quote from iContango :
This or two Fosi v3 monos... paired with a WiiM Ultra and a pair of Kef Q Concerto Meta speakers.
having used the fosi v3 monos with separate power supplies, I still recommend the monoprice amp over them.

The monos frankly just didn't sound very good. Channel separation was decent but that's about it. They sounded very unnatural to me.

I also have a topping mini300 and I thought that it sounded better than the monos - I'm not a class D hater.

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