Monoprice 150 watt 605030 Amplifier Review

[Vasr]

Nobody really wants this thread to go south so to be clear I did not accuse you of anything at all.

I suggest you try one sometime with an open mind. If your mind is closed when listening you will likely end up hearing what you want and not what is.

The above is never a good thing to say. Nothing needs to be said about open minds to anybody. It is condescending at best, obnoxious at worst. If you want to say it to people in general, then don't put it under my quoted post.

This is the equivalent of the Internet meme "if you only do your research" nonsense.

But moving on...

I have used a lot of pro-audio amps in my band gigs over the last couple of decades. Works fine for that purpose, some better than others. Almost none that I would keep in the house (except perhaps a couple that cost more than a good consumer amp) because the requirements are different and the cheaper prices just don't justify it in my experience. If cost is an issue, there are always refurbished ones and/or used ones that are much better bang for the buck without the noise/heat issues, etc. So, I don't see the appeal. From experience, I didn't see them as no brainers or agree with the assessment that one should keep the money for something else.

We can disagree for sure but it has nothing to do with open or closed minds. We should respect other people here enough to not have to mention that.

The practical problem is also that when you go looking for such amps, you really don't know what you are going to get (unless measured like in this forum) despite reviews (very few are reviewed for home consumer use). So, it becomes a bit of hit or miss and a time sink or waste of money. So, while I am open to there being some pro-audio amp out there that may be good enough for some in-home use, it is not just worth the time to find it unless the chase itself is the goal and the reward finding one really cheap. [/QUOTE]

 

[b1daly]

I feel like a strange thing has happened at ASR where people are actually expressing both in language and purchasing/selling decisions opinions about the quality of audio equipment based on inaudible differences in performance.

As a thought experimen, does anyone think that measured performance of this Monoprice amp represents audible difference in performance from other amps in the middle range of amps tested? Would it sound different/worse than the best amps on the ASR chart?

It presents an interesting case because it does have some deviation in frequency response which might be audible.

I highly doubt the distortion would be audibly perceptible.

The second part of my thought experiment is: if you were not able to distinguish this amp, or perhaps some of the better performing pro amps, from the best measuring amps would the measured performance be a factor in your purchase decision, and if so why?

The track record of people attempting to distinguish amplifiers in blind testing (with justified control conditions) is extremely poor.

The same issue I see with the DACs.

The one factor that might make me consider paying more for a higher performing amp is essentially a neurotic one: if I‘m hearing subjective deficiencies in my listening experience I can at least be confident the problem is not with the amp!

But there is a very ironic inversion happening in mass psychology here with the concept of the “objectivist“ audiophile ethos. The original cultural currency of the objectivist approach to audio was founded on the idea that there is a certain baseline performance in audio gear which represents “good enough” and there is no need to spend more to exceed this performance.

I find the performance reviews fascinating from a technology perspective but I am unconvinced that it makes sense to purchase/market gear with improved audio performance, other things being equal. If the performance can be delivered at little to no extra cost, then sure, why not.

For a while I was conceptualizing the desire for the best audio performance as akin to the desire to own a fast car even though you would never come close to driving it top speed.

But this doesn’t work that well because in the case of the car, it’s superior performance is actually perceptible, very much so.

Another irony is that Amir has demonstrated that some of the super high priced ‘boutique’ audio gear has relatively poor audio performance. This actually illustrates that once audio performance hits a certain level it is ’good enough’ and owners of such gear who enjoy it perfectly well are none-the-wiser.

Unless they happen upon ASR where their cherished piece of ‘audio bling’ has been shown to fall short of much more humble hear. Then they will start to suffer and hear all sorts of problems and ultimately be forced to unload that piece of garbage on some other unsuspecting fool, heh heh.

 

[PeteL]

I feel like a strange thing has happened at ASR where people are actually expressing both in language and purchasing/selling decisions opinions about the quality of audio equipment based on inaudible differences in performance.

As a thought experimen, does anyone think that measured performance of this Monoprice amp represents audible difference in performance from other amps in the middle range of amps tested? Would it sound different/worse than the best amps on the ASR chart?

It presents an interesting case because it does have some deviation in frequency response which might be audible.

I highly doubt the distortion would be audibly perceptible.

The second part of my thought experiment is: if you were not able to distinguish this amp, or perhaps some of the better performing pro amps, from the best measuring amps would the measured performance be a factor in your purchase decision, and if so why?

The track record of people attempting to distinguish amplifiers in blind testing (with justified control conditions) is extremely poor.

The same issue I see with the DACs.

The one factor that might make me consider paying more for a higher performing amp is essentially a neurotic one: if I‘m hearing subjective deficiencies in my listening experience I can at least be confident the problem is not with the amp!

But there is a very ironic inversion happening in mass psychology here with the concept of the “objectivist“ audiophile ethos. The original cultural currency of the objectivist approach to audio was founded on the idea that there is a certain baseline performance in audio gear which represents “good enough” and there is no need to spend more to exceed this performance.

I find the performance reviews fascinating from a technology perspective but I am unconvinced that it makes sense to purchase/market gear with improved audio performance, other things being equal. If the performance can be delivered at little to no extra cost, then sure, why not.

For a while I was conceptualizing the desire for the best audio performance as akin to the desire to own a fast car even though you would never come close to driving it top speed.

But this doesn’t work that well because in the case of the car, it’s superior performance is actually perceptible, very much so.

Another irony is that Amir has demonstrated that some of the super high priced ‘boutique’ audio gear has relatively poor audio performance. This actually illustrates that once audio performance hits a certain level it is ’good enough’ and owners of such gear who enjoy it perfectly well are none-the-wiser.

Unless they happen upon ASR where their cherished piece of ‘audio bling’ has been shown to fall short of much more humble hear. Then they will start to suffer and hear all sorts of problems and ultimately be forced to unload that piece of garbage on some other unsuspecting fool, heh heh.

I hear this argument once in a while, but I have yet to find a serious ABX test report that demonstrate that people don't distinguish amps in blind testing in controlled conditions. Maybe those report exists, but when I look I just don't find any demonstration of that. It is not the position of the audio engineering society, not sure about full amps but they where able to demonstrate that trained ears can distinguish op amps running in their linear zones. They release a few other articles and paper on the subject as well. May I ask where you take that: "The track record of people attempting to distinguish amplifiers in blind testing (with justified control conditions) is extremely poor." ? Seriously, maybe it's the case but I don't find a "track record" of that, and I read quite a bit about audio. I read a few thread diagonally here as well, and I don't think that it's ASR's position neither. @amirm can correct me if I'm wrong. That said, It's an interesting subject but I don't want to derail this thread from the product. We can take it to an other thread if it get's to trigger passionate arguments.

 

[restorer-john]

It presents an interesting case because it does have some deviation in frequency response which might be audible.

Bear in mind that frequency response plot is run at a mere 5W. Frequency response plots never improve as you go up in output power- they pretty much always get worse, especially with Class D.

 

[amirm]

Okay... very, very curious why not of course.

This is why: https://www.audiosciencereview.com/.../monoprice-605030-class-d-amp-teardown.16121/

 

[welsh]

I bought the Yamaha R-N303 for my daughter; she feeds it via WiFi, which is very handy. It claims 100 wpc but only 0.2% THD. So, probably transparent for her small room and you can't argue with the price. But not ideal for a larger room.

The system I need the amps for won't be for critical listening, but the rooms are fairly large (4,500 cubic feet), the speakers (M105) aren't especially sensitive, and their impedance drops to 3.8 ohms. Net, I want to have enough headroom to drive them hard. A little low pass DSP for the Revels wouldn't hurt, per Amir's recommendation. So, let's see what pops up.

 

[welsh]

I bought the Yamaha R-N303 for my daughter; she feeds it via WiFi, which is very handy. It claims 100 wpc but only 0.2% THD. So, probably transparent for her small room and you can't argue with the price. But not ideal for a larger room.

The system I need the amps for won't be for critical listening, but the rooms are fairly large (4,500 cubic feet), the speakers (M105) aren't especially sensitive, and their impedance drops to 3.8 ohms. Net, I want to have enough headroom to drive them hard. A little low pass DSP for the Revels wouldn't hurt, per Amir's recommendation. So, let's see what pops up.

I am new on this forum, and I do not have the technical knowledge that seems to be the hallmark of this site. Respects to all of you! I am currently using a Yamaha AS-801 amplifier with Revel m16 speakers, and it sounds much better than the stuff I was listening to in the dark days of the 80s... Thanks for the measurements!

 

[Bruce Morgen]

The 605030 costs just US $119 from Amazon including Prime shipping which is remarkably low.

If you buy it from Monoprice via overstock.com the price is a paltry $103.53 with free (U.S. only?) shipping.

 

[garbulky]

@amirm you just proved that warm up/break in is a thing! #Breakingnewground!

 

[Ron Texas]

I suppose it's OK for the money, but for a few bucks more you could get an A800. Once I had a Class AB amp which sounded nasty until it warmed up so I don't think the problem is unique. Thank you @amirm

 

[Bruce Morgen]

I suppose it's OK for the money, but for a few bucks more you could get an A800. Once I had a Class AB amp which sounded nasty until it warmed up so I don't think the problem is unique. Thank you @amirm

The A800 goes for nearly 3x as much based on what Monoprice is asking on overstock.com -- that's well over "a few bucks more" for the budget-conscious crowd. IMO its real competition is the Aiyima A07+SMPS combination for about $70-80 shipped (from China), which IMO would be a better performer in every way, albeit sans the balanced inputs and bridging capability.

 

[MakeMineVinyl]

I

As a thought experimen, does anyone think that measured performance of this Monoprice amp represents audible difference in performance from other amps in the middle range of amps tested? Would it sound different/worse than the best amps on the ASR chart?

It could be more audibly noisy with sensitive speakers than another amp, even with the same measured noise spec because of differences in noise spectra. Its a budget amp which is trying to get the price down to the bare minimum. Calling it 'professional' might be a bit of a stretch, since no large sound reinforcement company would go near one of these. Its more for casual users who are trying to get an amp for the least possible cost.

 

[ROOSKIE]

The A800 goes for nearly 3x as much based on what Monoprice is asking on overstock.com -- that's well over "a few bucks more" for the budget-conscious crowd. IMO its real competition is the Aiyima A07+SMPS combination for about $70-80 shipped (from China), which IMO would be a better performer in every way, albeit sans the balanced inputs and bridging capability.

I purchased this Monoprice amp yesterday and I was choosing between it and that very Aiyima 07.
I am still curious about the Aiyma and might send on in for testing if Amir is interested. (shipping from china though so long wait)
I am also curious why you are confident that the Aiyma is better in every way.
That amp would only have more power based on TI specs if it uses a huge power supply that is difficult to incorporate for many. The largest 36v 6a laptop style power supply and the other large 32v 5/6amp supplies are not going to allow that Aiyma to come even close to max output.
Additionally Signal to Noise and distortion are unknown but based on other Chinese small form factor chip amps might not be even as good as this Monoprice. Yes TI's own test amp is fantastic and so are some DIY examples but they cost much more and Aiyima may not come close to those specs in their ultra budget approach.
Still I am curious of course.

For those curious
prices as of tonight 9/22/20
$35 48v power supply that will need a case and wires https://www.aliexpress.com/item/4001351003158.html?spm=a2g0s.8937460.0.0.62d52e0epdN7lf
$47 Aiyima https://www.aliexpress.com/item/4000410819688.html?spm=a2g0o.cart.0.0.2d5c3c00fUNsfz&mp=1
$23 32v 5a laptop style https://www.aliexpress.com/item/33053341453.html?spm=a2g0o.cart.0.0.2d5c3c00fUNsfz&mp=1

$45-50ish with shipping 36v 6a laptop style https://www.audiophonics.fr/en/powe...apter-100-240v-ac-vers-36v-6a-dc-p-12735.html

$103 Monoprice amp from Overstock that I ordered (also I used Rakuten cash back as last night it was 10%, check around may go back up - now 1%)
https://www.overstock.com/Electroni...-Studio-Audio-Amplifier/18949601/product.html

P.S. *$80 for Aiyima 07 with no power supply at Amazon with prime
https://www.amazon.com/AIYIMA-A07-TPA3255-Amplifier-Digital/dp/B08CJZGT6H

 

[ROOSKIE]

I hear this argument once in a while, but I have yet to find a serious ABX test report that demonstrate that people don't distinguish amps in blind testing in controlled conditions. Maybe those report exists, but when I look I just don't find any demonstration of that. It is not the position of the audio engineering society, not sure about full amps but they where able to demonstrate that trained ears can distinguish op amps running in their linear zones. They release a few other articles and paper on the subject as well. May I ask where you take that: "The track record of people attempting to distinguish amplifiers in blind testing (with justified control conditions) is extremely poor." ? Seriously, maybe it's the case but I don't find a "track record" of that, and I read quite a bit about audio. I read a few thread diagonally here as well, and I don't think that it's ASR's position neither. @amirm can correct me if I'm wrong. That said, It's an interesting subject but I don't want to derail this thread from the product. We can take it to an other thread if it get's to trigger passionate arguments.

Wirecutter has done a few blind budget amp tests over the years but they didn't really include a control/ringer (all the amps were budget).
Reported differences were trivial though.
Brent Butterworth arranged them. He uses Revel speakers as his reference set and talks frequently about Harman research and Toole. I expect he fits in here. He rates amplifiers as one of the least important components along with DAC's. Anything decent by contemporary standard is at least very good.
I have done several sighted comparisons where I deff hear no differences and some where I deff do (but generally they were very minor)
Twice I have heard fairly major differences but that was in vastly wide price gaps. Bear in mind that usually any amp I have is at least "decent", not a lot of Awai stuff here. As stated earlier I deff heard differences between a $25 chip amp and a $1000 amp. Still they were fairly minor compared with changing speakers and honesty I do believe that not all would find the same amp the winner.

I already said this and so did others but at some point amps and the ridiculous prices become high end HDMI cables. That is just MHO, certainly not a final word and after all I am just a hobbyist.
Despite all of this of course I do want a Benchmark but I will settle for a kick-@ss Hypex DIY. Will it sound better than my other amps... Maybe, maybe not.

 

[Bruce Morgen]

I purchased this Monoprice amp yesterday and I was choosing between it and that very Aiyima 07.
I am still curious about the Aiyma and might send on in for testing if Amir is interested. (shipping from china though so long wait)
I am also curious why you are confident that the Aiyma is better in every way.
That amp would only have more power based on TI specs if it uses a huge power supply that is difficult to incorporate for many. The largest 36v 6a laptop style power supply and the other large 32v 5/6amp supplies are not going to allow that Aiyma to come even close to max output.
Additionally Signal to Noise and distortion are unknown but based on other Chinese small form factor chip amps might not be even as good as this Monoprice. Yes TI's own test amp is fantastic and so are some DIY examples but they cost much more and Aiyima may not come close to those specs in their ultra budget approach.
Still I am curious of course.

For those curious
prices as of tonight 9/22/20
$35 48v power supply that will need a case and wires https://www.aliexpress.com/item/4001351003158.html?spm=a2g0s.8937460.0.0.62d52e0epdN7lf
$47 Aiyima https://www.aliexpress.com/item/4000410819688.html?spm=a2g0o.cart.0.0.2d5c3c00fUNsfz&mp=1
$23 32v 5a laptop style https://www.aliexpress.com/item/33053341453.html?spm=a2g0o.cart.0.0.2d5c3c00fUNsfz&mp=1

$45-50ish with shipping 36v 6a laptop style https://www.audiophonics.fr/en/powe...apter-100-240v-ac-vers-36v-6a-dc-p-12735.html

$103 Monoprice amp from Overstock that I ordered (also I used Rakuten cash back as last night it was 10%, check around may go back up - now 1%)
https://www.overstock.com/Electroni...-Studio-Audio-Amplifier/18949601/product.html

P.S. *$80 for Aiyima 07 with no power supply at Amazon with prime
https://www.amazon.com/AIYIMA-A07-TPA3255-Amplifier-Digital/dp/B08CJZGT6H

Amazon's price for that Aiyima is ridiculously high -- as you noted, several AliExpress sellers offer them for $50 or less, and Aiyima's rep posted here that they will match any AliExpress price if you buy directly from their website. Forget using a power brick -- get an SMPS rated at at least 7A @ 48VDC and equip it with a suitable DC cable/connector and AC line cord. The Mean Well 7.3A model is fully enclosed, widely available for about $35, and has a thermostatically controlled fan that won't turn on unless you're pushing that little amp so hard that fan noise won't matter. The TPA3255's specs are much better than those of the IR setup in the Monoprice amp -- lower distortion and more available power as long you give it enough "juice," which make sense because it's 4-5 year old Class D technology vs. the 20+ year old IR chip+MOSFETs approach. Just tuck that SMPS out the way. BTW, I'm powering two A07s and an older TAS5630-based amp from a single generic 48V 10A SMPS with no sign of stress even at fairly high volumes driving three pairs of vintage JBLs -- I honestly think I could remove the SMPS's fan with no ill effects, but for now I just leave it off most of the time with the mini toggle switch I installed for that purpose.

 

[ROOSKIE]

Update for anyone interested here.
I like the look and feel of the amp. It is nice to plug SpeakOn connectors into a $100 amp.
I have used it a bit now with a set of Infinity R162's and DCM 160 Mini Floor standers. These are nice budget systems to try with this amp. So far the amp sounds pretty great. The gain setting match exactly on mine. I will eventually compare in some more meaningful way and try to determine if I hear better sound with a more expensive & better measuring amp.
For now I see no reason why this amp wouldn't work for a budget oriented person with one caveat, that fan.

The fan is seriously annoying. I immediately disconnected it and am running fanless. The unit gets warm but not hot. I have lots of breathing room around it. Still eventually I ought to put a silent fan in there... well maybe. I think the no-fan option is a real option in a typical stereo set-up.

 

[howard416]

The only thing that would be a dealbreaker here is the lack of thermal compensation (if indeed that is what causes the delay before good performance). And I say good performance because the distortion spectrum is actually quite good. The higher orders are very well controlled and the low orders, while probably not inaudible on their own, will be leagues under whatever a speaker can make (usually about 1-10% H2 and 0.1-1% H3).

The fan, well, whatever. Disconnect the fan or do a quiet fan upgrade. For the cost, no need to be nervous about doing any sort of mod.

 

[ROOSKIE]

For anyone looking to save bucks.
I bought several of these.

I disconnected the fans and have been using several of these in an essentially non climate controlled environment. They do have room to breath. The vents are on the bottom so keep that in mind.
I check them regularly and they are never more than slightly warm.
2 are being used in bridged mode and have been driven hard many times.

Sound quality wise I have tested them in my hifi rig with no obvious SQ degredation including bridged mode. I have not taken time to really compare them or do a blind test but I definitely want to and likely will sometime this year.

They really seem like reasonable units that met their published specs.
For many installs I can't fathom spending more. Even a nice home theater.
Maybe not a super hifi rig but who knows. These are pretty solid.

Plus I purchased 7 of them so far and spent under $700.
That is 14channels of 150x2 or 7channels of 500watts. Plus separate chassis if one channel fails. Plus low pull on the AC line due to class D.