SMSL A50 Pro Amplifier Review

[amirm]

I’m not sure what setups use a low-power, passive subwoofer but if I needed something like this, I would not let the SINAD scare me away.

The amount of power should however. While I did not measure the sub power, from my quick look of the internals, it is using the same IC as mono for the sub channel. Combine that with the small external power supply and you are not going to have nearly enough power for a proper subwoofer.

In typical cheap soundbars, what they call a "sub" is an 8 inch mid-woofer without much low end output to compliment the small midrange drivers in the soundbar. There, it is covering frequencies from 80 Hz and up, not 80 Hz and lower.

 

[audioje]

AL400 might be the first. Hopefully Amir can test it

Hmm it could be but doubt it would be stellar. Anyway, I think SMSL is not interested in making an amp-only device.

 

[shuppatsu]

The amount of power should however. While I did not measure the sub power, from my quick look of the internals, it is using the same IC as mono for the sub channel. Combine that with the small external power supply and you are not going to have nearly enough power for a proper subwoofer.

In typical cheap soundbars, what they call a "sub" is an 8 inch mid-woofer without much low end output to compliment the small midrange drivers in the soundbar. There, it is covering frequencies from 80 Hz and up, not 80 Hz and lower.

Yes, that’s why I said I wasn’t sure who uses “low-power, passive subs.” So implicit in my using it is that I had a use case for it.

Which, I dunno, a passive 2.1 nearfield setup for gaming?

 

[Geert]

How to recognize a real professional product? It doesn't have ’Pro’ in the name...

 

[GiBo61]

SMSL's dacs are great. But I haven't seen a good power amp yet.

That's not true. The SMSL VMV A2 amplifier has been rated more than positively here by Amir.

 

[HalSF]

It is not my job to be an audio historian. The product is on sale right now on major sites such as Amazon. I don't care if it was released a month ago or 5 years. If it is for sale, then it is a current product and to be reviewed as such.

And no, it is not easy to figure out when a product was released. It requires research and is not something I am going to waste my time on. You on the other hand, could have post that info, and explain why a solid state amplifier would have been fine to have a SINAD in the 50s in that time.

Thanks for responding. I’ll give it a rest now.

 

[paulgyro]

Does anyone know of a good alterative to this? I'm looking for something with the HDMI input. Next best thing I can find is a Wiim product.

 

[Barrelhouse Solly]

We consider this (see below) very poor distortion performance for an amplifier, but fantastic performance for a loudspeaker! This starts to puzzle me more and more: why all this focus on electronics while our loudspeakers show so much more distortion...

View attachment 504440

There's at least one variable that's very difficult to control in speakers, the material used for the cone or whatever vibrates. Resonances and "aiming" are easier to manage, but there's still the vibrating material.

 

[USER]

On one hand it is great to have the measurement showing it is not transparent, but at the same time, measuring as non transparent and being able to hear a difference with an other item measured to be totally transparent is not the same thing.
A proper listening test would also be interesting to me.
It is great to have high standards, but it is also great to have flexible inexpensive options which might perform just fine even if not to highest standards.

Owner here. I didn't spend much time with this before I sent it to Amir but I did put up some listening notes in the original product thread. TLDR, aside from some hiss when my ear was up by the tweeter it sounded as good as my Hypex NC252MP amplifier under general listening conditions. I was a bit surprised by the results, but that analog input never said, "use me" to me. Do keep in mind that specs say 78dB SINAD for the digital input so one can only get so upset by the results.

However details help make more sense of this. I used this in a set-up where the speakers are about 6 feet from me so I imagine I was hitting the SINAD sweet-spot of around 10-25 watts. If I was getting SINAD in the mid-70s then I really wasn't going to notice much, especially when you either hear hiss or not. To no surprise I was using the digital input with a Chromecast audio streaming Roon with DSP calibrated to my room so it was going to sound nice no matter what. Finally, and probably just as important, I got this because it uses 2 Infineon MA12070P chips and the Loxjie A30 mini amp that uses one of them performed well in a review here. So I was definitely biased and was even thinking 2 is better than one, lol.

That all said, this thing is extra tiny and is by far the best looking mini amp in my opinon. I liked that I could hide it in the fireplace mantle. The Hypex I normally use is a monster compared to it. I've seen this as low as $69 during sales and, while there will be better options at that price soon enough, I don't hate it for that price for something like a tertiary set-up or even for a teenager.

Added: The best thing about this is that it doesn't have a screen, just tiny perforations on the panel itself so it looks slick as hell when displaying info. Now I'm wondering how the HDMI input fares.

 

[dtaylo1066]

POS. A real stinker. Very disappointed in SMSL. Can't hold a candle to so many others in the category. Booooooo.

 

[amirm]

We consider this (see below) very poor distortion performance for an amplifier, but fantastic performance for a loudspeaker! This starts to puzzle me more and more: why all this focus on electronics while our loudspeakers show so much more distortion...

View attachment 504440

0.3% distortion at 1 kHz would not be fantastic in a speaker. Here is an example:

This is a powered monitor so we are seeing distortion of the amp+speaker yet it barely gets to 0.1%. And this is an acoustic measurement where microphone distortion and noise from the environment is included as well.

With respect to noise, speakers have infinite SNR since if you don't feed them anything, they don't produce anything unlike electronics which have residual noise.

Here is another Neumann speaker that has much less distortion at 1 kHz even at 96 dBSPL:

That is super loud playback of those frequencies by the way. So much so that I have to wear hearing protection to block them. Not so with a 5 watt output from an amplifier.

 

[French Meloman]

SMSL seems to be lacking inspiration these days. They messed up this product as well as their last CD player that NTTY just reviewed.

 

[Jimster480]

Keep in mind SMSL

But this is a SMSL amp not a SMSL DAC nor a Topping amp. If this was a Topping amp, or a SMSL DAC and measured like this then it would be an exception.

SMSL are not known for their amps.

They have made some great amps in the past. However this AMP has a DAC in it. This is how it can take HDMI ARC and Optical inputs.

The only cheap passive subs are usually diy ? Is this product for low cost diy enthusiasts ?

The passive subs I’m aware of are usually quite massive ones in a more expensive diy category ? People who have pa crossovers or mini DSP and separate power amps anyway ?

Makes sense as an amp inside a low cost soundbar mated with a cheap passive sub ? Not as an amp

Pretty low wattage for subs though?

 

[kaju666]

Hey

Did you saw that there is new version of this amp SMSL DA100.

It uses TAS5827 over MA12070P

What do you think, does this chip could be better?

 

[iGmole]

I have this.

It is audibly broken at low levels.

One great thing I learned from this review: apparently I don't need much power at all. I have found the power plenty sufficient for my TV watching with the humble 2.1 system I have. So, when planning a better amp setup, I have a reference. Yayyyy!

edit: in case SMSL is reading this, if you make a new version, perhaps called the A50 Pro Pro, with less noise and distortion, I'll buy it immediately. Surely you'll make it because one person on the interwebs said it's needed?

edit2: oh, there is a DA100 which, has the same features and a phase flip for the sub, and as per measurements provided by SMSL should be sonically superior. Maybe I'll order that one.

 

[ChenHui]

The A50PRO is incredibly compact, easily fitting into one of my racks and taking up less than 1U of height. It lets me control all its functions via remote, and its heat generation is virtually zero. This means I get great sound quality without compromising on heat dissipation, space, or ease of use. I highly recommend this amplifier.

 

[Kagemusha]

I also have this one and expected "not so good" review.
I bought it for $75 anf just for games/tv setupt. When listening music from youtube TV from the HDMI arc, I think sounds nice, same from the toslink via a wiim mini (I used the wiim room correction) sounds also ok to me.
I have a 2.0 setup only, Dalis little speakers, to me sound fine, all in 1 little box.
OTH the EQ presets are worthless

Compared to a loxjie A30 in my desk, the loxjie sounds much better to me.

 

[SWSL]

The only cheap passive subs are usually diy ? Is this product for low cost diy enthusiasts ?

The passive subs I’m aware of are usually quite massive ones in a more expensive diy category ? People who have pa crossovers or mini DSP and separate power amps anyway ?

Makes sense as an amp inside a low cost soundbar mated with a cheap passive sub ? Not as an amp

I have a DIY passive. I put a 10" Skar driver ($50 at the time) into a solid wood sealed enclosure @ 1cf. Sounds good to us! Doesn't require that much power. Works at home levels with a 3116 driving it. Prefer to avoid a plate amp and choose my own. I like setups where the good part is not taken out by the bad part. We matched our system with the Fosi BT30D pro using it's sub amp for dance parties. As we realized how hot it was running, I bought a budget 3255 sub amp and changed over to using the aux out. Same with this amp. Use the internal sub amp if power/heat are non-issues. Or, break out the aux signal and run a discreet sub amp. Having options is never bad. If they had implemented well with 3255 this might be the winner of the $100 amp category with all the input outputs options.

 

[Jimster480]

I have this.

It is audibly broken at low levels.

One great thing I learned from this review: apparently I don't need much power at all. I have found the power plenty sufficient for my TV watching with the humble 2.1 system I have. So, when planning a better amp setup, I have a reference. Yayyyy!

edit: in case SMSL is reading this, if you make a new version, perhaps called the A50 Pro Pro, with less noise and distortion, I'll buy it immediately. Surely you'll make it because one person on the interwebs said it's needed?

edit2: oh, there is a DA100 which, has the same features and a phase flip for the sub, and as per measurements provided by SMSL should be sonically superior. Maybe I'll order that one.

Check out Fosi here; they have great Amps at a lower price

I also have this one and expected "not so good" review.
I bought it for $75 anf just for games/tv setupt. When listening music from youtube TV from the HDMI arc, I think sounds nice, same from the toslink via a wiim mini (I used the wiim room correction) sounds also ok to me.
I have a 2.0 setup only, Dalis little speakers, to me sound fine, all in 1 little box.
OTH the EQ presets are worthless

Compared to a loxjie A30 in my desk, the loxjie sounds much better to me.

For $75 it can work alright for some cheaper speakers I suppose. I wouldn't personally run it though with the performance being so low.

 

[Bob101]

I would have thought that low noise would be important in a soundbar applications.

Maybe someone else has already answered your question (and better) but soundbars are not 'Hi-fi' products. In tv and movies the sound is called sonorisation, and that is what soundbars are 'designed' to work with. These are generally not very dynamic by nature. Complete silence in sonorisation is very exceptional. And noise, mostly hiss, is something a surprising lot of poeple (not on this forum) just put up with. Once the movie begins the noise is added to the soundtrack, and in a way veiled by it at the same time. So: noise in a soundbar is not the big issue it is compared to critical listening to, say, recorded acoustic instruments. And distortion: well, many people are used to cheap, small sound devices with lots of distortion and don't really mind, or don't even know what distortion is. I personally know someone who truly loves the sound of her the tiny built-in speakers, of a cheap flatscreen-tv, and finds full(er)-range audio confusing and bloated. A soundbar, good or bad, is useless. It just makes the same sound, no? This divice is after all still better than AM radio in the 50's. Considering the price you get a soundbar that delivers what a lot of people find acceptable for the price. Putting this in a power amp without much thought is, as shown above, not a good idea. Who is this product for? As a power amplifier it's just not cheap enough to be this cheap...