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Massdrop 789 vs. Monoprice 887 vs. SMSL SP200: THX amp measurement comparison

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RickSanchez

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Hey, guys.

My first time posting here.

I need a bunch of small-but-great headphone amps for my recording studio & also my band, as we use IEM's (not wireless) on gigs. I'd love to go with the Monoprice, and I might, but I need six of them, so... ouch.

I'd love to save and get the SMSL, but there are several things that worry me. Most important is the output impedance. My Studio cans range from 250 to 600 ohms (Beyer DT770's) so no problem there, but the IEMS we all use are the Shure SE846, which are incredible, but sadly 9 ohms.

So of course I want the lowest output impedance possible.
The Monoprice specs say only 0.05 ohms for the single ended output. Nice. SMSL doesn't give thast spec, and ignores my email query, but an independent test says its output is 1.3 ohms. That's a HUGE difference. Couple thatn with only 2 gain settings instead of 3, and I'm a bit worried.

SO A QUESTION: The Drop and Monoprice units don't recommend using a 9 ohm source, anyway. Monoprice says 14 ohm minimum, unless you are very dareful with the output voltage. (And them what about the sound quality?) So maybe I'd be OK, with ANY of these amps, if I added a 32 ohm L-pad to the input of the IEMs?

What do you think? I assume that all of these units would still have ample power. Would this give me a solid frequency response & damping?

Welcome to ASR.

I don't own any of these 3 amps, so I can't provide personal experience. I'll simply add a couple things to note:
  1. I remember reading on one of Amir's reviews that his test equipment adds about 1.0 Ohm to output impedance. So if the SE out of an amp measures at 1.3 Ohm in his tests it's probably more like 0.5 or lower. Unfortunately I can't remember what review that was, so it's something Amir would have to verify for you.
  2. If you do end up going with the SP200 I'd suggest checking in with the guys at Apos. They are doing price matching until the end of the year, and many ASR members have had good experiences buying through them. Worth asking them if they'd do a volume discount since you need six of them.
As for power, Amir doesn't measure down at the level of impedance you're asking about. But look at the distortion vs. power graphs (33 Ohm) for the three units. The SMSL SP200 kicks out 1.8 watts on low gain, 2.9 watts on high gain. Tons of power there.
 

Cableaddict

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Thanks, Rick. That helps a little.

Any idea about the power supply?
 
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Veri

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Another question about the SMSL vs the US -made THX amps:

Why has no one mentioned the power supplies? They appear to be radically different, and as we all know, the psu is a huge factor in how any piece of gear sounds.

I don't know what the maximum rails this circuit can run on, but more voltage swing is always desireable.
AFAIK, the best headphone amps all use 24v rails.

The Drop uses a 24v DC wallwart. Im assume it's a quality, regulated supply. (yes?)
The SMSL, however, uses a fully-internal psu, and it appears extremely small. Aditionally, it says +/- 18v right on it, although they claim the unit runs at 24v. My understanding of electronics gets a little hazy at this point, but I asked them to explain. Their response was:
"24W is the output. 18V is input. +/- 18V = 36v. 36v x 667mA = 24W."

Hmm. So does that make sense?
Do the US-made units also run on 18v rails?

Does any of this make anyone hesitant about the SMSL?
(If not, then great I can maybe save a lot of money.)

thanks.
You can look at the left side of the measurement dashboard and in both the Drop, SMSL and Monoprice amp there is NO mains in the signal. There's no PSU noise to speak of.

So no, the power supply won't affect the sound here, that is mostly audio myth as has been debunked time and time again.
 

Cableaddict

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Veri, it's not about NOISE. It's about transient response and LF.

The need for a good power supply is no myth. I've owned a recording studio for 30 yearas, and dealt with ulktra high end gear & mods my whole life. I've done extensive, careful double-blind tests on more gear than I can count, and believe, me, it's no myth.
S/N ratio is literally the last thing I care about.
 

Veri

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Uh-huh. "Believe me" doesn't really convince me, no offense.
 

Cableaddict

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No offense taken.

I know what I know. (& so does every EE I've ever worked with over these many years.)

- But you're certainly entitled to a different opinion.
 
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stefan2305

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Ya know, the interesting thing is that previously, I would've seen a post like this and immediately began to salivate at the idea of buying something that will beat my THX AAA 789, but things have kind of changed for me. Ever since I spent a lot of time comparing the headphone output in listening tests between my RME ADI-2 DAC and that of the 789, and came up empty handed as they sounded basically identical to me, the 789 has basically just been gathering dust. I keep it in case I need the power at some point I suppose, but I figure if an HE-1000 is fine with the RME...well...simplify the chain and be done and happy. So it's an absolute joy to see companies investing in making truly magnificent works of engineering, but I guess the question becomes, at what point does it no longer matter from a practical perspective? And further, am I at the limit of my own hearing and others can hear the difference between these two, or are we just chasing the gear (which is ok too)?
And even more importantly, once we are at the limit (if there is one), what will be the next audio revolution that we'll see or want to see. Sorry if this is a mini thread hijack. Feel free to ignore it. Just some musings on how far the industry has come and its merits.
 
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RickSanchez

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Ya know, the interesting thing is that previously, I would've seen a post like this and immediately began to salivate at the idea of buying something that will beat my THX AAA 789, but things have kind of changed for me. Ever since I spent a lot of time comparing the headphone output in listening tests between my RME ADI-2 DAC and that of the 789, and came up empty handed as they sounded basically identical to me, the 789 has basically just been gathering dust. I keep it in case I need the power at some point I suppose, but I figure if an HE-1000 is fine with the RME...well...simplify the chain and be done and happy. So it's an absolute joy to see companies investing in making truly magnificent works of engineering, but I guess the question becomes, at what point does it no longer matter from a practical perspective? And further, am I at the limit of my own hearing and others can hear the difference between these two, or are we just chasing the gear (which is ok too)?
And even more importantly, once we are at the limit (if there is one), what will be the next audio revolution that we'll see or want to see. Sorry if this is a mini thread hijack. Feel free to ignore it. Just some musings on how far the industry has come and its merits.

" ... but things have kind of changed for me." Well, it's not just you; the market has changed. The Monoprice THX 887 and the SMSL SP200 are new entrants to the market, both use THX technology, and both are in the same price range as the Drop THX 789. Having 3 units like this wasn't a thing a year ago. And what you mention in your post is sort of the point of why I put Amir's measurements side-by-side. I wanted to show how closely these products measure against each other, and other than receiving a defective unit there wouldn't be any audible difference between any of them. All three are SOTA headphone amps. Which means that potential buyers should focus on:
  • output impedance (depending on what headphones you're driving)
  • output power
  • features (e.g., 2 gain settings vs. 3 gain settings, XLR headphone out, etc.)
  • price (although all three are very close in price)
  • build quality / warranty / customer service
  • aesthetics
So while we're not at the limit of what can be engineered, you're right: we're at or getting very close to the limit of what matters in terms of human hearing. You can buy and be happy! You don't have to worry about upgrade-itus every 2 years or so.

For me personally I hope that the continued engineering advances result in a few products that have the same basic form factor, same ballpark price range (higher, but not significantly higher), and same performance but as stereo / power amps -- for low power desktop speakers, not HT -- instead of headphone amps.
 
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b1lf

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" ... but things have kind of changed for me." Well, it's not just you; the market has changed. The Monoprice THX 887 and the SMSL SP200 are new entrants to the market, both are THX certified, and both are in the same price range as the...

Technically, they are not 'THX certified,' they have THX chips. 'THX certified' usually means THX test components from another company (ie HT speakers / AVR / etc). Correct?


Thanks for the summary / comparison review, new member (long time lurker) looking to upgrade my Mayflower ARC to something higher end. I'll likely get the Monoprice 887, the SMSL SP200 or perhaps the Monoprice THX AAA DAC/AMP combo.
 
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RickSanchez

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Technically, they are not 'THX certified,' they have THX chips. 'THX certified' usually means THX test components from another company (ie HT speakers / AVR / etc). Correct?

Correct, poor choice of phrasing on my part. I've edited that post to reflect "THX tech" not "THX certified". Thanks for pointing that out.
 

JohnYang1997

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Technically, they are not 'THX certified,' they have THX chips. 'THX certified' usually means THX test components from another company (ie HT speakers / AVR / etc). Correct?


Thanks for the summary / comparison review, new member (long time lurker) looking to upgrade my Mayflower ARC to something higher end. I'll likely get the Monoprice 887, the SMSL SP200 or perhaps the Monoprice THX AAA DAC/AMP combo.
It's more like certified, authenticated, authorized than else. There are only off the shelf parts here. There are certain performance criteria the manufacturers have to meet in order to have their name on. Though, unlike other certification, this is actually called IP module. THX provides critical circuits and design requirements. They help the manufacturer to meet their criteria. If in the end the performance and design criteria are not met (very small chance), they can't have the THX name on.
In detail. Except for the lowest end models, which are new silicon chips, 788 888 789 are all using off the shelf parts only. 788 uses ad8397 from analog devices inc and opa1602 from texas instruments, 789 888 887 use opa564 and opa1602/opa1612 from texas instruments.
 

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... I'm still torn on which to purchase.

  • SMSL SP200 offers good value, I don't own any IEMs so the 'lack' of gain control isn't a negative to me.
  • Monoprice THX 887 seems like it has the best performance (slightly) and my personal preference over the Drop THX 789.
  • Monoprice THX AAA 788 / AKM 4493 combo seems like a great package with a moderate clunky UI & volume knob


The if I buy a stand alone AMP, I'd likely pair it with a Topping D50s DAC (up for suggestions).

Looking at the charts, the Topping D50s measures only slightly better than the Monoprice combo unit:
https://www.audiosciencereview.com/...-index-of-measurement-comparison-charts.8246/





Do you guys generally suggest separates? Any other input with the above concerns?
 

Veri

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... I'm still torn on which to purchase.

  • SMSL SP200 offers good value, I don't own any IEMs so the 'lack' of gain control isn't a negative to me.
  • Monoprice THX 887 seems like it has the best performance (slightly) and my personal preference over the Drop THX 789.
  • Monoprice THX AAA 788 / AKM 4493 combo seems like a great package with a moderate clunky UI & volume knob


The if I buy a stand alone AMP, I'd likely pair it with a Topping D50s DAC (up for suggestions).

Looking at the charts, the Topping D50s measures only slightly better than the Monoprice combo unit:
https://www.audiosciencereview.com/...-index-of-measurement-comparison-charts.8246/





Do you guys generally suggest separates? Any other input with the above concerns?
I'd personally go for one of the monoprice boxes if budget allows.
 

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... I'm still torn on which to purchase.
  • SMSL SP200 offers good value, I don't own any IEMs so the 'lack' of gain control isn't a negative to me.
  • Monoprice THX 887 seems like it has the best performance (slightly) and my personal preference over the Drop THX 789.
  • Monoprice THX AAA 788 / AKM 4493 combo seems like a great package with a moderate clunky UI & volume knob
The if I buy a stand alone AMP, I'd likely pair it with a Topping D50s DAC (up for suggestions).

Looking at the charts, the Topping D50s measures only slightly better than the Monoprice combo unit:
https://www.audiosciencereview.com/...-index-of-measurement-comparison-charts.8246/

Do you guys generally suggest separates? Any other input with the above concerns?
The Topping D50s is a fine DAC. You might consider that it is not an XLR capable DAC. That may not be an immediate concern to you, but for me, I wanted a DAC that could take full advantage of my 887's features. Just eliminating ground loop possibilities right from the start was worth it to me.

I chose to go the separate DAC / amp route because I really wanted the 887 amp, and because I prefer the flexibility it gives in changing one or the other in the future. Examples: "Dang! I would like to try that spiffy expensive exotic Tube Amp", or "Ooo, that new DAC has a huge color LCD that shows the track playing and displays a Kansas City Chiefs logo when idle!
 

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The Topping D50s is a fine DAC. You might consider that it is not an XLR capable DAC. That may not be an immediate concern to you, but for me, I wanted a DAC that could take full advantage of my 887's features. Just eliminating ground loop possibilities right from the start was worth it to me. ...
Depending on your noise environment, and length of separation (why would you separate them?), an RCA to XLR adapting cable, properly wired, is about as good.
 

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Could I ask a huge favor for you to compare the DX7 Pro headphone amp to any of the THX 887 so we can see what one might be giving up by going with a combo device?

I wouldn't get the DX7s over the THX, the THX is like fine wine and the other is well.. a better dac then headphone amp. You get the DX7s to pair with the THX IMO. At the end of the day they are great products and it is all that you can afford. Good luck.

Someone needs to A/B the Monoprice to the Massdrop, that has yet to happen. I am waiting for this to make the jump to the 887, The 887 is a better amp but is it 460 dollars better? People will say it is not, but have they compared both side by side?
 
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b1lf

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The Topping D50s is a fine DAC. You might consider that it is not an XLR capable DAC. That may not be an immediate concern to you, but for me, I wanted a DAC that could take full advantage of my 887's features. Just eliminating ground loop possibilities right from the start was worth it to me.

I chose to go the separate DAC / amp route because I really wanted the 887 amp, and because I prefer the flexibility it gives in changing one or the other in the future. Examples: "Dang! I would like to try that spiffy expensive exotic Tube Amp", or "Ooo, that new DAC has a huge color LCD that shows the track playing and displays a Kansas City Chiefs logo when idle!

I think deep down, this is what my inner tech-nerd brain is telling me. I like the flexibility...


That said, what DAC would you suggest pairing this with that has XLR?

The Topping D50s is priced around $185 which is about what I’d want to pay in the immediate future for a DAC.
 

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I wouldn't get the DX7s over the THX, the THX is like fine wine and the other is well.. a better dac then headphone amp. You get the DX7s to pair with the THX IMO. At the end of the day they are great products and it is all that you can afford. Good luck.
Someone needs to A/B the Monoprice to the Massdrop, that has yet to happen. I am waiting for this to make the jump to the 887, The 887 is a better amp but is it 460 dollars better? People will say it is not, but have they compared both side by side?
I'm not sure what you mean by "is it $460.00 better?". The 887 is $399.99, the 789 is $400.00 (a whole penny difference :) ).
 

Celty

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I think deep down, this is what my inner tech-nerd brain is telling me. I like the flexibility...

That said, what DAC would you suggest pairing this with that has XLR?

The Topping D50s is priced around $185 which is about what I’d want to pay in the immediate future for a DAC.
I picked up the SU-8 for $170 and no regrets there. Some new models by SMSL and Topping are coming, but pricing AFAIK is not known yet. There are a number of other choices, it's just a matter of what performance and features you care about most, within your budget range. I would not care if the DAC was gold plated and had every feature known to man, I am not spending $4000 on a damn DAC.
 
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RickSanchez

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I wouldn't get the DX7s over the THX, the THX is like fine wine and the other is well.. a better dac then headphone amp. You get the DX7s to pair with the THX IMO. At the end of the day they are great products and it is all that you can afford. Good luck.

I believe MediumRare was asking for a comparison of the headphone amp section of the DX7 Pro (not the DX7s) vs. the Monoprice 887. Both are top performers from a measurement perspective, although as Amir says in his conclusion about the DX7 Pro: "The headphone is a step below state-of-the-art from measurement point of view." The upside is you also get the DAC with the DX7 Pro. Perhaps the major knock against DX7 Pro (depending on your headphones) is the somewhat high output impedance of the 1/4 jack at 6.2 Ω.

Someone needs to A/B the Monoprice to the Massdrop, that has yet to happen. I am waiting for this to make the jump to the 887, The 887 is a better amp but is it 460 dollars better? People will say it is not, but have they compared both side by side?

Up to you, but my advice is don't hold your breath. That's the point of doing this type of comparison: the measurements show these are both SOTA headphone amps. In a blind level-matched A/B test the highly likely outcome is that it would be impossible for you to tell the difference. So considering the prices are the same between the two you can decide on features, warranty, customer service, etc.
 
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