Monoprice 113194 25 Watt AB Power Amplifier Stereo Hybrid Tube Amp with Bluetooth

Midgetguy

Headphoneus Supremus
Pros: Solid build, looks pretty good, plenty of power
Cons: Doesn't sound like a tube amp, Bluetooth EMI, quality control
Introduction:
A few months ago, Monoprice released their multi-function amp for the budding audiophile looking for a classic tube sound. I say multi-functional because it includes Bluetooth! Standard RCA-in is great and all, but sometimes you just wanna connect it to your Spotify playlist running on your phone. You can plug in headphones or hook up speakers in the back as well, making it a great all-in-one choice for a desktop setup. It's at a fantastically low price considering what they tout it can do and it looks pretty nice. But how did they do? Let's find out!
 
Disclaimer:
I bought this amp directly from Monoprice. I’m not affiliated with them in any way nor am I being compensated for this review. It is my honest opinion. That said, I’ve also now returned this amp for reasons you’ll learn about later in the review.
 
About Me:
Before we get to the nitty-gritty of reviewing this amp, let's preface with who the person behind the review is! I'm not an "audiophile", I'm not a sound engineer, I'm not a professional of any sort in the audio world, I'm not even an experienced person in the audio world; I'm just some guy in college who likes to listen to music and is just a bit too curious sometimes for his wallet's good. I've barely written reviews on anything, so this review likely won't be that good either
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. I won't say I listen to a wide range of music, but I can appreciate many genres and I understand not everyone likes everything, it's just the way the world pans out. I've mostly been listening to various forms of electronic music as of late, but occasionally rock, video game soundtracks, and jazz can all end up on my plate. I've stopped listening to almost all recently popular music with few exceptions and for good reason; it's almost all terrible.
 
The Review...
I'm gonna try to make this review really simple, mostly because I have absolutely no clue how to make it complicated. We're gonna think about how it looks and how it functions. For those of you who don’t wanna read most of the following blocks of text, there’ll be a TLDR section at the bottom.
 
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So here we have the Monoprice Stereo Hybrid Amp. Look familiar? Probably. I'm not going to get into what other amps I've seen around the web that look like this, but the gist is that there are several; the one branded by Monoprice just happens to be the one I bought. Here are the specs straight from the Monoprice product page for those of you that love the numbers:
 
Frequency Response: 20Hz ~ 20kHz ± 2dB
Total Harmonic Distortion: 0.1%
RMS Power Output (4-ohm load @ 1kHz): 15 watts/channel
Peak Power Output (4-ohm load @ 1kHz): 25 watts/channel
Output Impedance Range: 4 ~ 16 ohms
Input Impedance: 47 kilohms
Input Sensitivity: 300mV
Signal-to-Noise Ratio: 85dB 
Treble Adjustment Range: -10dB ~ +10dB
Bass Adjustment Range: -10dB ~ +10dB
Input Voltage Range: 100 ~ 120 VAC, 50/60 Hz or 220 ~ 240 VAC, 50/60 Hz
Fuse Type: F2AL/125V (110v) or F1AL/250V (220v)
Tube Types: 6N1 and 6P15 (both Chinese-made I believe)
Dimensions: 10.6" x 5.9" x 11.8" (268 x 150 x 300 mm)
Weight: 8.2 lbs. (3.7kg)
 
How does it look and has it fallen apart yet?
Honestly, it looks alright and it has yet to fall apart. Looks are subjective so it's always hard to rate something like this. But to me, Monoprice has put together something that doesn't look terrible. I'll admit that, at the same time, it wouldn't be out of place in a hipster's room who literally has nothing plugged in but the power cord. Speaking as a millenial, even I find that stupidly pointless. The entire unit feels pretty solid, being made of aluminum with the glossy parts being some sort of wood/wood composite. Color scheme is on-point for my tastes - the gloss black compliments the aluminum and tube array very well. There's a VU meter on the front and while I don't really understand the point of it other than providing more faintly-glowing eye-candy, it is at least eye-candy and glows in the same orange shade that the tubes glow.
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Speaking of which, while tubes also add a nice visual element, it's just not so well-implemented here. The ring structures are too busy and distracting from a design view. On the front face of the amp, we've got all those dials and the power button in addition to the VU meter mentioned earlier. At first glance, it looks fine, but when you look closer, you can start to ding points off for fit and finish; the power button, treble, and bass dials are all a little off-center.
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How well does it work?
Now we get to the core of whether or not this is a good product. For reference, this amp is being fed by a Topping D20 DAC taking in both lossy and lossless files by optical cable from my PC. The listening is done through my beloved set of Sennheiser HD600s and a set of Monitor Audio Silver 1 bookshelf speakers (2014 edition). Additionally, the treble dial is set to 0 and I've set the bass dial to 2 for reasons I'll explain a little further down.
So what do I think? This rates a very solidly "meh". It's better than the average "meh", but it ain't exactly blowing my socks off. Let's start with the good points about it. It has a 1/4" jack, something definitely right and not a point I'd be able to say about my Topping TP30mkII. The tubes (and let's be clear, Monoprice DOES say that this is a hybrid amp, implying the tubes are only for the pre-amp stage, with a solid state amp circuit powering the mains) appear to be doing their jobs, but I’ll get to exactly why it doesn’t seem that way in this next section.
The main issue with this though is that the tubes are clearly part of the circuit, but something about their implementation makes it less about the tubes and really more about where you have the dials turned to. Now we get back to why I have the bass dial turned to 2. With everything turned to 0 as I’ve seen some people recommend, this unit is all show, no go. Unless you’re a treble-head, there’s no reason to be moving the treble dial, so that’s all fine and dandy, but I’m no bass-head, yet I needed to turn the bass dial up. What gives? This is a tube amp; the tubes should provide the warmth even if it’s only from the preamp circuit. It’s how every other tube amp on the market works. But in this case, keep everything at 0 and you get something that has no warmth and sounds a bit thin and anemic. No kick in the low end, no authoritative feel to tracks that should have it; doesn’t matter if I’m dealing with HD600 or the Silver 1s. With the bass dial at 2, things sound much more like I’d expect them to, which is fine, but then what’s the point of the tubes? The dials just allow for physical EQing (simply speaking, though I’m aware it’s not as simple as that nor do I know exactly how the dials do what they do), so really it’s just whatever the bass dial does that gives it the slight difference in sound compared to my TP30mkII.
If you’ve looked at the product page, you’ll also note that this unit has Bluetooth built-in as well. So does it work? Mostly, yes pretty well actually. I can’t attest to range as I only tried from within the confines of my small room (probably about 10’ x 20’) and there was never a signal problem in terms of range. However, the EMI is terrible; I’m exaggerating a little bit, but it’s incredibly prominent during the quieter or purposefully silent parts of your music. My verdict is that it’s perfectly adequate for casual listening through speakers, but I’d steer clear of using headphones and streaming from Bluetooth because the EMI is just too noticeable.
 
What’s wrong with it?
As you can see from the top of this review, I gave this amp 3/5 stars: super average. There are several reasons for this, one being what I described earlier about how it doesn’t sound warm enough for it to be even a hybrid tube amp. Another reason, also described above, are the EMI issues with using Bluetooth. I’m inclined to ding it less for that just because that’s part of the nature of wireless audio in its current state; one just has to accept that there’s gonna be EMI noise, but this is definitely worse than I imagined it would be. The build also shows a couple very minor flaws, but I can see many people not being too concerned with them: the dials and power button are very slightly off center. But the single largest problem, aside from how it doesn’t sound like what it’s advertised to sound like, is that you’ll be gambling on the quality control. While I can forgive the slightly off-center dials and button, I cannot forgive the royal screwup that happened on my unit; the L/R channels for the headphone out were reversed. Very specifically the headphone out; I didn’t notice for the first couple of days because I only used it with my speakers, but I noticed that it was backwards on the headphone out when I was using my headphones one night and playing Halo 5.
 
TLDR:
As promised: a TLDR section to sum up my thoughts on this amp.
 
Pros?
  1. Solidly built.
  2. Great overall aesthetic: gloss black and aluminum are right in balance and the finish looks good.
  3. Provides more than enough power for a desktop setup, whether you’re using speakers or headphones.
  4. Treble/bass dials allow for simple EQ
 
Cons?
  1. Fit and finish: you can see how some stuff doesn’t fit together exactly as it should with the dials and power button being just a little off-center.
  2. EMI using Bluetooth: a lot of it. Fine for casual listening on speakers, too much for headphone use.
  3. Quality control: I could accept it if a tube was broken when it arrived, but unlike a tube breaking, L/R channels do not simply switch while in transit.
  4. Sound: weirdly not tube-like. In fact, thinner and colder than my solid-state TP30mkII when the dials are all set to 0.
 
Concluding Thoughts:
Is this a good amp? Tough question; in terms of bare minimum in capability, yes, but as an introduction into tube-style amps, not so much in my opinion. Construction is solid and the balance of aluminum panels plus gloss black elements is great. The addition of dials on the front allow for simple EQing and the Bluetooth streaming is decent as long as you don’t use headphones. The amp is also plenty powerful for any desktop setup whether you use headphones or speakers. Monoprice started with a decent design and they certainly priced it competitively, but the way it ends up sounding coupled with some quality control issues leaves me reluctant to recommend it to people for main and long-term use.
If you’d like to experiment and try it out, then by all means, I actually say go for it. It was an interesting study to see how Monoprice would do in this arena and I don’t regret trying it, but I had high hopes that they could produce a good product at an affordable price; that just didn’t end up being the case. If you try one for yourself, I hope it goes better for you than it has for me.
And thus, we end up at the 3/5-star score: was almost good, didn’t quite make the cut.
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Thanks for putting out this review, I was looking at this amp but I guess some things are too good to be true.
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