Originally published 3/13/21.
- 3/19/21. Article revisit.
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Who is this Amplifier for? How does it sound? How does it compare with other amps without the THX moniker?
All of these answers and more, comin’ up in this S.M.S.L SH-9 Headphone Amplifier Review!
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At A Glance
In The Box
S.M.S.L Headphone Amplifier
Remote (AAA Batteries not included)
Specs & Features
- Price: Check Apos! | Check Amazon!
- Inputs: Balanced x1, Unbalanced x1
- Outputs: Balanced x1, Unbalanced x1
- Output Power: 6W x 2 @ 16 Ohm, 3W x 2 @ 32 Ohm, 440mW x 2 @ 3oo Ohm, 220mW x 2 @ 600 Ohm
- Signal-to-noise ratio: 137dB, A-Weighted
- Output Noise: 1.9uV, A-Weighted
- THD+N: -123dB, 0.00006% (A-Weighted)
- THD+N: -117dB, 0.00013% (20Hz – 20kHz, 32 Ohm, -3dB)
- THD: -125dB, 0.00006% (1kHz, 16 Ohm, -3dB)
- Input Impedance: 47k Ohm
- Output Impedance: Near 0 Ohm
- Frequency Response: 0.1 Hz – 500kHz (-3dB)
- Gain: Low (+0dB), High (+10dB)
- Power Supply voltage/frequency: AC100-240V, 50-60Hz
- Power consumption (EN60065): 24W
- Power consumption in standby mode: <0.1W
- Size: 187.5 x 154 x 40 (mm)
- Packing size: 282 x 232 x 79 (mm)
- Weight: 790g
- THX AAA-888 Headphone Amplifier with THX AAA Technology
- 6 Watts into 16 Ohm, 3 Watts into 32 Ohm Headphones with lowest THD+N
- 0.1 Hz to 500 kHz (-3dB) Frequency Response
- Ultra-Compact Design, Perfect for Desktop Systems
- Balanced Stereo Headphone Output
- Balanced Stereo Line Input
- High Precision Resistors for Temperature Stability
- Pop-less Design with High-Quality Relays
- High precision and low noise 256 level relay volume control
- 2 Positions Switchable Gain Control
- Fully Protected with DC, Over-Voltage, Over-Current, Short-Circuit and Thermal Protection on Headphone Amplifier
- High-Efficiency Ultra-Low-Noise Power Supply
- 1.9 inch LCD display
Who is the SH-9 for?
Dubbed the Smissle (by me), this Desktop Amplifier with Bluetooth capability targets the audiophile snob with its balanced XLR headphone input and balanced XLR dual inputs on the back for use with a separate DAC.
You can also use the SH-9 single-ended (unbalanced) with its RCA inputs.
Do keep in mind that this is an Amp only; you will need a separate DAC for it to function. Beginners Guide: What is a USB DAC?
On the front, we’ve got an XLR input for your balanced cables, as well as a single-ended 6.35 mm (1/4″) jack for use with unbalanced connections.
The middle contains the interface, and on the right, there’s the volume potentiometer.
Hold the volume pot in to bring up the menu. It’s a short hold. A long hold turns the unit off. For me, this is a minor nitpick. Sometimes I end up turning the unit off by accident.
Here you can cycle through your input, gain, volume mode, brightness, etc.
To back out, hold the volume pot in again.
I like the minimalist design of the amp. There are large numbers indicating what volume I’m at, an RCA switch (indicating mode), and a gain switch. These are both indicators and are for reference only, they’re not actual switches that can be ticked.
On the back, there’s an AC power jack for the supplied cable, as well as the RCA inputs, and the Balanced XLR inputs.
Build-wise, it feels incredibly robust and solid in your hands, and it’s just about the perfect size for full-time desktop use.
How does this bad boy sound though?
- Source(s): Tidal Hi-Fi, Spotify Premium, FLAC, MQA.
- Headphones used: AKG K702, AKG K712, AKG K371
- DAC Used: iFi Zen, AudioQuest DragonFly Red
- Playlist: S.M.S.L SH-9 Playlist
- Albums: Listed below!
It’s interesting to note that this amp utilizes what’s known as THX technology. What is THX AAA Technology In Audio & Video?
THX is a way to certify amplifiers that perform at a high level – by reducing distortion to almost nothing while maintaining the cleanest signal possible.
In the case of the SH-9, those qualities ring true, but, does it sound any better than a FiiO K5 Pro; an Amp/DAC that does not utilize THX? I went back and forth extensively trying to discern any differences, and I couldn’t.
Both are very clean sounding, but the K5 Pro may be a tad warmer. This is likely due to its somewhat higher output impedance at 1.2 Ohm. The SH-9 is advertised as close to 0. What is Output Impedance?
The problem for me boils down to Total Harmonic Distortion numbers. We’re talking about a potential difference that comes down to fractions of a percentage.
The S.M.S.L advertises less than 0.00006% vs. 0.004% for the K5 Pro. Looks like a big difference at first glance, but in reality, isn’t when you’re actually listening to music.
I’m bringing this up because THX’s main claim to fame is low distortion and a clean signal.
The truth is that most Amplifiers nowadays already have super low THD – it’s already entirely minuscule if we’re being honest.
The words “THX Technology” stamped on the top of the SH-9 don’t make me want to buy it over any other amp, especially when I can pay less and achieve the same effect.
Even with that said, it can be beneficial to have one simply because of the balanced feature; something I plan to invest in for myself down the road.
Overall, the SH-9 is certainly a good product, but I wouldn’t recommend it as there’s something better on the horizon that’s packed with a lot of useful features and will act as your central hub for doing pretty much anything in a home listening environment.
Well, that’s about it for today my friend! I hope you’ve enjoyed this S.M.S.L SH-9 Review & Discussion, and came away with some valuable insight.
Questions? Comments? Requests? Did I miss the mark on something? Please let me know down below or Contact me!!
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