SMSL PA40
| Speaker amplifier |
SMSL PA40, one of the newest power amplifiers from SMSL.
The SMSL PA40 joins the always expanding catalog of amps from the brand.
The SMSL PA40 is, specifically, part of the affordable Class D amplifiers, providing an very good option to build up an audio system when paired with other SMSL devices like the SMSL DO100 or SMSL DO300EX.
FIND ALL: Headphones Scores Compared
MORE: Reviews – Headphones, Music Players, DAC, DAP, Amp, Cables
SEE ALSO: DAP/DAC Reviews
SMSL PA40 Review
Tests & Scores
A
Accessories & Packaging
The unit comes in the same style of cardboard box seen on SMSL amp/DAC devices.
With the amp you will also get:
• 1x power cable
• 1x IR remote control
3.25/5

D
Design
We could say that the SMSL PA40 has a coherent aesthetical style and look with many other SMSL products that we have reviewed (SMSL AO100, SMSL HO100, AO200 MK2, DO100, DO300EX), thus making it a viable option to build up a good looking audio system.
Nonetheless, in our opinion, it is also one of the least “appealing” of them in the overall visual feel – obviously, this is a 100% subjective personal sensation.
The amp has a mid-large size, inline with the AO200/DO300 series as it includes a built-in power supply, we prefer this design over audio devices with an external PSU.
The front panel has a minimalistic approach with a big knob and a big rectangle that seems to be a very large screen but of which just less than 40% of this “window” is a true display.
The rear section of the amp is where you will find all the input/output connectors (including the power cable connection and power switch), while the bottom is well supported by 4 generously grippy feet.
The exact dimensions/weight of the SMSL PA40 are: 191.4×41.6x185mm and a weight of 1260g (2.77lbs)
3.75/5
OC
Operation & Control
The SMSL PA40 has a dual personality regarding its operation and control; from one side the amp is extremely simple and straightforward to use with a single knob/multifunction button that can fully control the device and a 2nd way of using/controlling the machine through an IR wireless remote control (included), which has more buttons and an even easier way of setting the amp.
Nonetheless, the dual personality arises when users try to make full use of the features and settings of the amp where they need to navigate through the menus and options of the display screen.
This display has a totally opposite approach with a cumbersome and unintuitive user interface that uses “coded” references to each option/menu/setting with single or double letter and a number; which at the end of day will result in users either learning and memorizing each letter and its reference or having to grab the user manual more often than not to see what and where you are – on top of that, the calculator-styled fonts are far from attractive.
Once you memorize this coded letter/number referencing you will gain access to multi-adjustments and finer-sound tuning features.
3.75/5
MORE: Earphones Amplification Power Comparison
MORE: Best Basshead Earphones
SEE ALSO: Best Fun Sounding Earphones Chart
CB
Construction & Build
Despite sitting as a budget-friendly model, the SMSL PA40 does not have too much to envy regarding build quality compared with other higher-tier offers from the brand.
In fact, so far, we have found that SMSL does not cheap out in the construction and feel of their devices, independently to the tier that they belong.
You will notice a full main metal case/shell and gold-plate audio connectors and a smooth volume knob rotational movement – the only plastic parts are the front panel, knob, banana plug “nuts” and the power switch.
4.5/5
MORE: Best Headphones for Libraries Chart
SEE ALSO: Best Earphones for Bed
C
Connectivity
The PA40 follows the minimalistic design also in its I/O offering having one input connection and 2x speaker output connections.
The specific I/O connections are:
Inputs
• RCA input (for a DAC)
• Detachable 3-prong power cable connection
Outputs
2 channel Stereo Banana plugs (for 2x passive speakers)
3.5/5
RELATED TO THIS: Active Noise Cancelling Headphones Reviews
S
Sound
In the past we have reviewed power amplifiers with a smaller but more powerful output than the SMSL PA40 but to be fair with the SMSL, most of these competitors kind of “cheat” here as they use external power supplies, while the PA40 is built-inside the device.
Said so, the SMSL PA40 can still boast a respectable 165Wx2 maximum power output, which is more than enough to drive most of passive bookshelf models on the market (do consider, though, that 165W are achieved at 4Ω and drop to 85Wx2 at 8Ω) and, in the case of our specific tests, driving multi-driver floorstanding premium speakers.
Same as we highlighted in the Construction & Build section, SMSL also tends to equip quality audiophile components inside their products and the PA40 is no exception with a German Infineon MA5332 amp chip and a JRC’s Japanese electronic volume chip control (NJU7391A); in fact, combined with all the internal guts, the SMSL PA40 showed during the sound tests a remarkable clean sound, no hints of hiss nor interference and the same pristine performance either set in low or high gain.
Moreover, the electronic volume control made the amp free of scratching volume regulation noises and at the same time preserved the phenomenally well-controlled channel balance.
A further characteristic of this amp was the natural sound profile and respectable separation exhibited, with some minimal upper extension boost (of course, this will directly depend to the source and DAC that you use with the SMSL PA40) while still offering many sound tuning options that included bass, treble control in 14 steps of adjustment for boosting or taming and also access to 6 pre-made EQ presets.
All of these sound-tuning features were far from a gimmick and provided net immediate sound effect, that even the most novice audiophile will feel.
Indeed, according to our measurements the SMSL PA40 was able to boost (either up or down) peak frequencies in up to 14.5dB – a boosting potential that not many budget amps are able to reach.
Sound Technical Specifications
• Max Power Output: 165Wx2 @4Ω
• SNR: ≥100dB
• THD: <0.004%
• Power Amp Chip: MA5332
• E-Vol chip: NJU7391A
• Input Power: 40W
• Frequency Response Range: 20Hz-20kHz
4.5/5
MORE: Editor’s Picks Earphones Chart
MORE: Best Bang for the Buck Earphones


SEE ALSO: Coupons – Discounts – Deals – Promo Codes – Sales Deals

SMSL PA40 Scores
- Accessories - 6.5/106.5/10
- Design - 7.75/107.8/10
- Operation & Control - 7.75/107.8/10
- Construction & Build - 9/109/10
- Compatibility - 6/106/10
- Screen - 6/106/10
- Connectivity - 7/107/10
- Sound - 9/109/10
- Features - 8/108/10
- Value for Money - 7.75/107.8/10
Summary
✅ Cheap price
✅ Good power-performance/price ratio
✅ IR remote
✅ Strong EQ & bass/treble control
✅ Built in PSU
✅ Solid build
❌ Display info not intuitive
❌ Only RCA input
FIND ALL OUR: Earphones Reviews / In-Ear Headphones Reviews
MORE: Best Earphones Charts
Buy it from:
SEE ALSO: Coupons – Discounts – Deals – Promo Codes – Sales Deals
RECOMMENDED FOR YOU: Headphones Frequency Response Curves
SEE ALSO: KZ Headphones Frequency Response Curves
SMSL PA40 Technical Specifications
Type | Amp |
---|---|
USB DAC | No |
Max output | 165W x2 |
Balanced | No |
Headphone jack | No |
Screen | Yes |
Speaker amp | Yes |
Remote | Yes, IR |
PSU | internal |
IR remote | Yes |
Class | D |
Type | 2.0 |
YOU WILL ALSO LIKE: Amazon Coupons & Deals
SEE ALSO: Aliexpress Coupons – Discounts – Deals – Promo Codes – Sales Deals
MORE: Hybrid Earphones Reviews