S.M.S.L FBA_SA-98E - Black Accordion Accessory (SMSL SA-98E)

Yes, it's inexpensive, but it's also quite a good amplifier!Other reviewers have provided various opinions about what this amp can do. The following are some actual measurements I did:At 1% distortion levels, I measured output power levels of about 54W per channel into 8 Ohms and 115W into 4 Ohms.A more conservative power rating for this amp would be 50W and 110W into 8 and 4 Ohms respectively, at < 1.0% thd. That's certainly enough clean power for most speakers.This amp is very efficient, as expected with class D. During these power output tests the dummy load resistors I used became way too hot to touch, while the amp itself remained completely cool.Total harmonic distortion (thd, at 1kHz) is 0.06% for 1W and 0.1% for 10W into 8 Ohms, and 0.08% and 0.1% at 1 and 10W into 4 Ohms. That means at most listening levels distortion won't be audible.Frequency response goes below 5Hz and is smooth with a slight gradual rise to about +0.2 dB around 16kHz, down 1dB around 26kHz and falling rapidly after that, which is pretty much inherent in a class d amp. That is pretty smooth.Output impedance is about 0.2 Ohms, which is probably just a reflection of the output device's "on" resistance. That gives damping factors of 40 and 20 at 8 and 4 Ohm loads, which is pretty good (other amps have better damping factors but I think better than 20 gives diminishing returns!)Finally noise (inputs shorted measuring 20-20kHz) is 140 (left channel) and 174 (right channel) uV into 8 Ohms, corresponding to a signal to noise level of -103 and -101 dB at full power (50W per channel) into the 8 Ohm load. That's pretty quiet!Two complaints -- 1) with the supplied 36V 5A power supply you aren't going to get the power outputs I mention above driving both channels at once. That probably doesn't matter for most listening purposes, but, you could substitute a different power supply -- Amazon lists a 36V switching power supply that puts out 13.5 amps for less than $50 -- that would really drive this amp, probably giving the power levels I mentioned both channels driven simultaneously. You'd need a good selection of high power dummy load resistors to test this!And 2) the gain with the volume control at max is about 35 dB. That means for most inputs you have to turn the gain way down to not blast your speakers, which in effect throws away some of your signal to noise. It would have been better if the gain was 8 dB or so lower. The chip manufacturer data sheet shows overall gain is selectable, but the SMSL implementation doesn't support that, unfortunately.Bottom line, for most 2-channel home audio purposes this amp would be hard to beat!One final point -- I sure would like to know why this amp is listed as a "Black Accordion Accessory!" Mine did not include an accordion, thankfully.

This is a really good amp, however the cable that comes with the power supply is total junk. At first it seemed like it was not getting very loud and there was some distortion but it sounded ok. Then after a week it stopped working. Looking at it, I noticed that the power supply has a three prong plug going into it and a two prong wall plug. I have a drawer full of these plugs(standard computer cable), so swapped it out and it worked fine. In fact it was much louder and cleaner. I cut the old plug to take a look. I don't know how it was powering the amp as it looked like 26 or 28 gauge wire. Very thin, I think I broke the connection at some point inside the cord. So its a great amp, just toss the cord that comes with it.

VERY strong amplifier, loud enough to drive even the biggest of speakers. Make sure the power adapter plug is plugged into the amp first or you'll get a nice spark.The sound quality was disappointing with little soundstage and a lack of clarity or crispness found in the Grace Digital (which is a much weaker amp). Listened to by itself you wouldn't necessarly notice the flaws. Compared to the Grace Digital 513 side by side and even the most novice listener can spot the defects. Otherwise a reliable amp for powering outdoor speakers where the staging and audio quality deficiencies won't be noticed. Power brick for this amp is, literally, the size of a brick; no surprise given the wattage this little amp produces.

This may be fine for computer speakers, but it's way under powered for the listed rating. I wish I had looked at the power rating closer. Specs list 160w per channel at 10% THD (distortion) at 4 ohms. This is on par with the Pyramid Gold or Roadmaster car audio power ratings you saw sold at the flea markets back in the 90s, completely unrealistic. The industry standard is .08 THD at 8 ohms. SMSL over rating this by more than 10 times what a reputable amp manufacturer would use. This unit does not have a headphone output so it cannot even be used to drive headphones. I was able to drive a pair of Boston Acoustics bookshelf speakers to moderate levels(not loud) before becoming distorted. Not what I was hoping for with all the positive reviews. The other problem is the sound was thin and lacked definition. You would need some form of EQ to make this sound decent even at low volume levels. I recommend the Pyle Home PCAU46A for 60 bucks. It is also overrated, but is more like 45w per channel and sounds much better with the bass/treble controls. Plus it has headphone output and USB/SD/.25" jack inputs for added flexibility. It is twice the size but much better than the SMSL. I should have known an amp this small could not possibly be 160w per channel.