Monoprice Monolith 7-Channel Amplifier Review

[TheAVInsider]

We all know this, but Captain Obvious needs to say Monolith is a vendor and not a manufacturer. Monolith is a house brand of Monoprice. The Monolith 7x is made by the OEM ATI made to the specs Monoprice has chosen. Monoprice has very little control over QC at the manufacturing facilities. Final product build QC is likely where the vendor comes in at.
Monoprice has listened to the community, and added a feature,XLR, that some felt the original was lacking. Monoprice has been trying to acquire this product for over a year, and have made some promises they could not keep, or control. Trying to do some fire damage lately, Monoprice the vendor, NOT ATI the manufacturer, have chosen to share some information to help explain the status of inventory, now that these are finally beginning to become available.
Like most new products, there are growing pains, like QC and supply issues, and early adopters can occasionally end up becoming beta testers as well.
I have one single interest here, and that is to deliniate the difference in amplifier topology between the discontinued Monolith 7 and the new replacement model Monolith 7X. Specifically the exact type of devices used to establish a balanced XLR within the amplifiers I/O circuitry.
I am looking for assistance from ATI, Monolith, Audioholics, the forums, and any techs, engineers, and self proclaimed experts to add to the discussion. Of course I expect the usual trolls as well, but they seem to talk quieter when you just ignore them.
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My System
Main system : Panasonic TC-P60ST60 plasma; Denon AVR-X6200W; Outlaw 5000; OPPO UDP-203; Klipsch RSW-10 sub; extemely modified Klipsch Chorus II Fronts; extremely modified Klipsch Forte II center; modified Klipsch Chorus II surrounds; modified Klipsch Academy rear heights; JBL L20T3 front heights; Mogami 10ga speaker cables, Mogami interconnects; custom gaming pc

Secondary system LG 47" LCD; Onkyo tx-nr818; OPPO UDP-83 JBL 240Ti Fronts; JBL L40T3 Center; JBL L100T3 Surrounds; Mogami cables; custom htpc/server.

Storage Vault: enter password

 

[M Code]

The supply issue @ ATI is regarding the availability for electrolytic power supply capacitors...
The parts supplier is air shipping in additional quantities from the Orient..

Just my $0.02...

 

[TheAVInsider]

The supply issue @ ATI is regarding the availability for electrolytic power supply capacitors...
The parts supplier is air shipping in additional quantities from the Orient..

Just my $0.02...

Electrolytics, do we know who makes the ones you spoke of? Nichicon? Erse? I know outside the signal path it's non critical.

 

[Squishy Tia]

Good meowning

I'm currently searching for a decent amp to go with the Yamaha CX-A5100 I'm gearing to purchase, but would like something a bit more southerly in price than Yamaha's MX-A5000. As I currently have only a 5.1 setup with no real plans for Atmos anytime soon (it's a bedroom/computer area, so not much space for it anyway), and the fact I plan on bi-amping the two front RTi-A9 channels in vertical bi-amp as I'm currently doing now with my two Adcom GFA-555 MkIIs, the Monolith 7X looks very appetizing.

The problem I'm having with this review, however, is that the review starts out talking about the Monolith 7, but then gives bench results for the Monolith 2, with zero 5/7 channel benchmarks shown. Additionally, the internals shown are also the Monolith 2, and not the Monolith 7.

As I'm looking for accuracy, this is somewhat concerning. I found the review of the MX-A5000 to be fairly thorough, but for some reason this one is lacking. Has Audioholics performed any updated review for the M7 or the updated M7X (XLR capable version)? It'd really be helpful to have better benches than just the pitiful M2 benches when reviewing the M7/M7X.

 

[PENG]

Good meowning

I'm currently searching for a decent amp to go with the Yamaha CX-A5100 I'm gearing to purchase, but would like something a bit more southerly in price than Yamaha's MX-A5000. As I currently have only a 5.1 setup with no real plans for Atmos anytime soon (it's a bedroom/computer area, so not much space for it anyway), and the fact I plan on bi-amping the two front RTi-A9 channels in vertical bi-amp as I'm currently doing now with my two Adcom GFA-555 MkIIs, the Monolith 7X looks very appetizing.

The problem I'm having with this review, however, is that the review starts out talking about the Monolith 7, but then gives bench results for the Monolith 2, with zero 5/7 channel benchmarks shown. Additionally, the internals shown are also the Monolith 2, and not the Monolith 7.

As I'm looking for accuracy, this is somewhat concerning. I found the review of the MX-A5000 to be fairly thorough, but for some reason this one is lacking. Has Audioholics performed any updated review for the M7 or the updated M7X (XLR capable version)? It'd really be helpful to have better benches than just the pitiful M2 benches when reviewing the M7/M7X.

Why not keep the Adcom and just get the Monolith 5. The 5 seems to have the best power reserve and only cost slightly more than the 7 in terms of $/W.

 

[AcuDefTechGuy]

Good meowning

I'm currently searching for a decent amp to go with the Yamaha CX-A5100 I'm gearing to purchase, but would like something a bit more southerly in price than Yamaha's MX-A5000. As I currently have only a 5.1 setup with no real plans for Atmos anytime soon (it's a bedroom/computer area, so not much space for it anyway), and the fact I plan on bi-amping the two front RTi-A9 channels in vertical bi-amp as I'm currently doing now with my two Adcom GFA-555 MkIIs, the Monolith 7X looks very appetizing.

The problem I'm having with this review, however, is that the review starts out talking about the Monolith 7, but then gives bench results for the Monolith 2, with zero 5/7 channel benchmarks shown. Additionally, the internals shown are also the Monolith 2, and not the Monolith 7.

As I'm looking for accuracy, this is somewhat concerning. I found the review of the MX-A5000 to be fairly thorough, but for some reason this one is lacking. Has Audioholics performed any updated review for the M7 or the updated M7X (XLR capable version)? It'd really be helpful to have better benches than just the pitiful M2 benches when reviewing the M7/M7X.

Keep in mind that is amp is built by ATI, not Monoprice. So I would not have any concerns about powering any speakers.

Two channels driven continuously into 8-ohm loads:
0.1% distortion at 215.9 watts
1% distortion at 255.6 watts

Two channels driven continuously into 4-ohm loads:
0.1% distortion at 345.6 watts
1% distortion at 400.6 watts

Five channels driven continuously into 8-ohm loads:
0.1% distortion at 185.8 watts
1% distortion at 223.5 watts

Seven channels driven continuously into 8-ohm loads:
0.1% distortion at 178.5 watts
1% distortion at 211.9 watts


Read more at https://www.soundandvision.com/content/monoprice-monolith-7-amplifier-review-test-bench#p8f8ePUVPRg2k0jw.99

 

[Squishy Tia]

Why not keep the Adcom and just get the Monolith 5. The 5 seems to have the best power reserve and only cost slightly more than the 7 in terms of $/W.

Because the Adcoms apparently require electrical bonding to the AVR/prepro here. They don't have XLR connections, and with the M7X having at least equal power capability to the speakers and a hefty enough capacitor reserve (though nowhere near the two channel headroom the Adcom's 2x 60,000µF capacitors deliver), the M7X makes the better choice since I want all my speakers connected the same way. Having a lower noise floor helps too. And in an environment where I've got cables running from a plethora of devices, including a rather beefy PC in a relatively confined area, the cleaner the signal the better.

Plus, a single connection at the power source is a lot easier to deal with.

I doubt I'm going to run into any real distortions on the M7X as the only two super power hungry speakers are the two bi-amped RTi-A9s that even my trusty ol' Yamaha RX-A3000 couldn't power with any authority even in just two channel mode. The CSi-A6 center and TSi-200 rears (no 7.1 for me yet, which would be overkill in this room anyway and not worth the budgetary hassle currently) work fine powered from the A3000. Or they did until its DSP decided to crack all of its FBGA joints, a defect that will almost certainly affect all of Yamaha's current Aventage AVR models since they've not changed manufacturing methods on that line yet. Thankfully the prepros don't get as hot as the AVRs and thus put less stress on those RoHS flavored solder joints.

 

[PENG]

Because the Adcoms apparently require electrical bonding to the AVR/prepro here. They don't have XLR connections, and with the M7X having at least equal power capability to the speakers and a hefty enough capacitor reserve (though nowhere near the two channel headroom the Adcom's 2x 60,000µF capacitors deliver), the M7X makes the better choice since I want all my speakers connected the same way. Having a lower noise floor helps too. And in an environment where I've got cables running from a plethora of devices, including a rather beefy PC in a relatively confined area, the cleaner the signal the better.

Thank you for explaining, but if you are so concerned about the RTiA9 being so hungry then you may want to consider getting the M2X and M5X. If you read my post #30 in the link you will see my slight concern (not really but..) about the M7X power reserve.

https://forums.audioholics.com/forums/threads/emotiva-or-outlaw.111219/page-2

Get both, plug each into a dedicated 15 A outlet and the RTiA9 will never be hungry again.

 

[jsc1979]

Just st a heads up. The 20%off code on Monoprice today works on the M7 amp. Takes off $320! Sunny20 is the code.

I bought one. Couldn’t resist it when it under $1,300.

 

[swechsler]

One thing that confuses me about this amp: with 7 channels into 4Ω, at full power you could easily exceed the capability of a 15 amp, 120 volt circuit, and while the amp does use the higher-current IEC power connector (C19 connector, vs the C13 that you commonly see on desktop computer equipment), it's still not rated for 20 amps.

 

[RichB]

^ It could and this is true of most high-powered multi-channel amps. ATI will tell you that its amp delivers that performance but the your power will not.

In reality, there will not be real world content that will require full power into all channels simultaneously and sustained.

So ATI, and Monolith is rating their amps as other do. The Parasound A51 is rated at 400WC x 5 or 2000 watts. Also not happening with a Class A/B and 15 amp circuit.

Short term, you can get much more than 15 amps out of the wall without tripping the breaker.

- Rich

 

[PENG]

It is the short term dynamic that matters for home audio applications. I am saying this for the nth times, go with the 5X200 watts version for potentially/theoretically best short term dynamic capability. The argument for the 5X200 would become even more compelling if you insist on wanting true ACD "continuous" (subject to definition) capability for reasons cited in post#130 and 131.

On the other hand, some multichannel power amps do come with two plugs, for psychological reason.

 

[jsc1979]

I just got my Monolith 7X yesterday. Man what a beast! When it was in the box it was difficult to handle, but unboxed it wasn’t bad at all. Build quality and aesthetics on these are very nice. The 20% off coupon worked on this amp last week and saved me $320. I couldn’t pass it up for that price and the coupon didn’t work on any of the other amps. Not sure if it was a glitch and I got lucky?

When I first hooked it all up I had a wicked ground loop hum. Narrowed it down to my cable tv. Unplugged the coax cable from the cable box and it disappeared. To fix it I routed the coax cable through my Panamax mr4300 and it took care of the hum. I was about to order one of those $20 isolators on amazon but luckily this worked. I will have to look at how the cable installer grounded it.

I’m only running 3 channels on it right now, but will run all 7 when I get my basement room finished. I’m thinking about getting an AC Infinity aircom for it as my console is enclosed (7” of open air above it and opening to the rear to make room for it.) I haven’t had a chance to listen to music or movies at higher volume so not sure how hot it will get running 3 channels.

 

[jsc1979]

One thing I’ve noticed on some pictures of these amps online.

In the older pics you can read a tag on the transformers that said Amplifier Technologies.

On the Monoprice website the pic of the amp shows the transformers with a sticker on them that says Noratel.

Wondering if ATI is no longer winding the transformers for these?

 

[RichB]

ATI uses Noratel. Here is a picture of an AT6002.


- Rich

 

[jsc1979]

ATI uses Noratel. Here is a picture of an AT6002.
View attachment 24471

- Rich

Ahh, thanks for the info! I wasn’t aware of that. On the ATI website they only talk about winding their own.

 

[M Code]

ATI used Noratel to supply the torroidal power transformers used in the MonoLith line of amplifiers. Noratel has an established, automated factory in Poland and they are capable of supplying the higher qty volumes @ a more competitive price than locally produced in the California b y ATI. The transformers are well made and meet the European CE standards...

Just my $0.02...

 

[Verdinut]

ATI used Noratel to supply the torroidal power transformers used in the MonoLith line of amplifiers. Noratel has an established, automated factory in Poland and they are capable of supplying the higher qty volumes @ a more competitive price than locally produced in the California b y ATI. The transformers are well made and meet the European CE standards...

Just my $0.02...

Would you know if Noratel are the ones manufacturing inductors for Jantzen of Denmark?
In recent email exchanges with Jantzen, when I was interested in some of their iron core inductors for my speaker company at the time, I was told that they were shipped from Poland and that shipping to Canada would rather be expensive.

 

[M Code]

Would you know if Noratel are the ones manufacturing inductors for Jantzen of Denmark?
In recent email exchanges with Jantzen, when I was interested in some of their iron core inductors for my speaker company at the time, I was told that they were shipped from Poland and that shipping to Canada would rather be expensive.

Hmmm..
Don't know for sure, but most likely yes..
Noratel has factories in Poland, Finland, Sweden, Norway but my understanding is that the Noratel factory in Brøndby, Denmark is for medical instrument/equipment not audio. Most likely U are aware Denmark has had some well respected loudspeaker companies including ScanSpeak now owned by Eastech..
Also Noratel has a large factory in Shenzhen, China..

Just my $0.02...

 

[Homolka]

Thanks for reviewing this one. Is there a chance to review the IOTAVX AVXP1? Iotavx came out of Nakamichi and the power amp seems a pretty good deal
Thanks
Daniel