Bob

SMSL A100 Sub-$100 Audio Amp

For the past few months, I’ve been using an inexpensive amp that performed far better than you’d assume after hearing the price:  Under $100 total.  It’s got analog RCA inputs and built-in bluetooth, with two speaker outputs, as well as a line-level subwoofer output if needed.  If you’re looking for a small, cheap amp that performs really well, this might be it!  More details below the link / picture:

SMSL A100:  https://retrorgb.link/smsla100

First, I need to start by repeating that this amp sounds great for the money.  This isn’t going to have the same amazing analog sound as the NAS 316bee and it doesn’t come close to the features of the awesome Marantz I recently reviewed.  But I strongly believe it performs much better then you’d expect from a sub-$100 amp and think it’s worth sharing.  Especially if you’ve found a pair of magnetically-shielded bookshelf speakers and wanted a good, but cheap amp to test it with!  My use case was a bit different, but I’ll share anyway…

I purchased this amp, to power some ceiling speakers I mounted in my kitchen.  At the time, my requirements were only that it was small and didn’t draw too much power when not in use.  I asked around and this was recommended by an audiophile, so I tried it out – I figured for the price, why not? (click the picture for a full-sized view)

I used basic 3.5mm to RCA audio cables to connect an old Apple Airport Router that I’d configured as only an AirPlay station.  I powered on the unit, set the input…and was shocked.  It sounded good.  I mean, not “audiophile good“.  But I never would have guessed a sub-$100 amp would sound like that.  I then tested the bluetooth connection and it sounded just about the same as analog-in.

Used AirPort Router via paid eBay affiliate link:  https://ebay.us/Djc6hA

While I normally don’t worry about power consumption for things like this, I planned on leaving it on 24/7, so I can just send music from my phone without any other interaction.  I connected my power meter and played a song.  As expected, the higher I turned up the volume, the more power was drawn.  When I stopped the track, the power dropped to about 2 watts…which is exactly what I’d hoped!  There isn’t an official “standby” mode, but when no signal is sent, it simply doesn’t amplify anything, essentially accomplishing the same thing.

I didn’t test the USB functionality at all though.  It’s supposedly a driver-free PC installation and works well, but I don’t have a scenario I’d use an amp like this, as my speakers are self-powered.  I bet it would be great if you have a high-end gaming PC and need an amp to power some bookshelf speakers!  I also didn’t try the subwoofer output, but that should be pretty straightforward:  Just connect it to a self-powered sub’s RCA-input.

The only complaint I have is a very small one:  If there’s a power outage, the amp will default back to a different input, requiring you to manually toggle to the aux RCA inputs.  This isn’t an issue in almost any scenario other than mine and simply hitting the input button puts it back the way it was, but I wanted to mention this as SMSL said they won’t be changing this in a future firmware update.

Overall, the amp was awesome for the price, small and something I think many people might be interested in.  Just remember that if you’re using it near CRT’s, you’ll also want to pair it with some magnetically shielded speakers!

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