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SMSL A100 Review (Stereo Amplifier)

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 33 18.5%
  • 2. Not terrible (postman panther)

    Votes: 100 56.2%
  • 3. Fine (happy panther)

    Votes: 43 24.2%
  • 4. Great (golfing panther)

    Votes: 2 1.1%

  • Total voters
    178

staticV3

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@TheBatsEar if I understand correctly, then the A100 uses the inductance of your speakers as part of its output filter.
People like Archimago who have the time to read up on their DUTs will modify their setup to produce data that's representative of real-world usage.
Amir on the other hand just plugged the A100 into his APx555 even though it was not designed to drive purely resistive loads.

So in that sense, I don't think it's fair to say
If the measurements are bad, they are bad because of the manufacturing.

Edit:
Here is dr_mick's original post where they describe this in more detail.
 

TheBatsEar

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@TheBatsEar if I understand correctly, then the A100 uses the inductance of your speakers as part of its output filter.
People like Archimago who have the time to read up on their DUTs will modify their setup to produce data that's representative of real-world usage.
Amir on the other hand just plugged the A100 into his APx555 even though it was not designed to drive purely resistive loads.

So in that sense, I don't think it's fair to say


Edit:
Here is dr_mick's original post where they describe this in more detail.
Got you.

Every speaker is a different inductance, so the filter is different with every speaker. They don't tell that to their customers. Sorry, i stick with it, it's the manufacturers job to sell a amp that works always, regardless of the nature of the load. Others do.

Is there something the manufacturer could have done to make this a nonissue? Yes, and it would have cost only cents in production, if i understand @dr_mick51 correctly.
 

dr_mick51

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Well, nobody (except you maybe, you seem to be knowing what you are doing) will change, remove or add SMD parts on a cheap amp to get less distortion.

If the measurements are bad, they are bad because of the manufacturing. No value in changing things around until they measure better if there are other manufacturers that do a better job. You can't make a nun out of a pig. :p

USB and BT seem to be indeed an afterthought. But it doesn't have to be like that, we have seen others having acceptable USB/BT performance in low cost devices.
I agree with you. But also many people will agree with me that modding is a huge part of this hobby. If you can get better performance by changing/adding things why not?
I prefer to do it myself than allow the manufactures to do it themselves and then charge 50 - 100 %.
There is not a single piece of audio equipment I have not modded or planned to mod.
Some people have and some people don't have the desire to mod things.
 

TheBatsEar

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I agree with you. But also many people will agree with me that modding is a huge part of this hobby. If you can get better performance by changing/adding things why not?
Fair enough, i'm not saying we shouldn't mod the stuff we have. But i think Amir shouldn't have to mod the stuff to get better measurments.

There is not a single piece of audio equipment I have not modded or planned to mod.
Keeping my eyes peeled then for your other mods :cool:
 

dr_mick51

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Fair enough, i'm not saying we shouldn't mod the stuff we have. But i think Amir shouldn't have to mod the stuff to get better measurments.


Keeping my eyes peeled then for your other mods :cool:
I understand, how would Amir knows? Right? He would need to open the amplifier to realize there are not inductors. The thing is that some audio equipment are meant to be heard, others are meant to be heard but also to be measured. In this case to measure the amplifier properly you need to simulate a "real" inductive load.
I agree SMSL just cheap out and caused this for a couple of cent. Maybe they realized of this issue and the next batch of A100 will come with these chokes? That's why it's so hard to find this amp currently?.

On the other hand, I've seen Amir to swap opamps, tubes and power supplies during his tests, sometimes he even changes the sensitivity/gain by increasing the input signal voltage. Don't these changes count as modding as well?
I mean, he does not need to open the amplifier , cut traces and solder smd chokes. Those chokes can be added to the output terminals. Is this not allowed? If that's how the amplifier chip is supposed to be measured and clearly stated on the Datasheet? I don't consider this modding, it is called proper test setup.

Again, I'm not blaming Amir, how was he supposed to know?
 
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dr_mick51

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I'm not going to debate what the manufacture should or should not do. In the end it's their product. All I can say is they missed a big opportunity here, they really screwed up by not adding those chokes which would allow Amir to properly test this amp and show the world how good it is for the price.

But independently of how it measured, it sounds really nice, and for me it's what matters.

Imaging this, for $90 you get an amp that rivals and excels the Loxjie A30 which is twice the A100 price and all this without doing any mod to the amp.
 

dr_mick51

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I realized that if we want to add some chokes to the amp (for peace of mind) it will only cost you 6 dollars (the 4 chokes)
MFG_AIAP-03.jpg
,
and you don't need to mess with the board. You can easily add those chokes before the output terminals(internally), just desolder the cables and add those chokes in between.
1652981378256.jpeg



P.S: And to end the debate about the USB cable, the amp comes with the Type A to type A USB cable. I don't know why Amir did not see it in the box.
 

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TheBatsEar

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I understand, how would Amir knows? Right? He would need to open the amplifier to realize there are not inductors. The thing is that some audio equipment are meant to be heard, others are meant to be heard but also to be measured. In this case to measure the amplifier properly you need to simulate a "real" inductive load.
Nope. To deliver acceptable results the manufacturer should have put in the inductances to allow good performance regardless of the load.

I agree SMSL just cheap out and caused this for a couple of cent.
And that is all there is to it. They cheaped out and thus measured badly. Go figure.
Enough others that don't make that mistake.

Maybe they realized of this issue and the next batch of A100 will come with these chokes? That's why it's so hard to find this amp currently?
It's more likely they saw demand wasn't as they expected and didn't do another batch. Or maybe a part is unavailable now.
Pretty sure development has moved on to the next iteration.

On the other hand, I've seen Amir to swap opamps, tubes and power supplies during his tests, sometimes he even changes the sensitivity/gain by increasing the input signal voltage. Don't these changes count as modding as well?
It does. And i don't like it. But it's his AP.:cool:

I mean, he does not need to open the amplifier , cut traces and solder smd chokes. Those chokes can be added to the output terminals. Is this not allowed? If that's how the amplifier chip is supposed to be measured and clearly stated on the Datasheet?
Was this instruction part of the amps manual?
 

dr_mick51

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Was this instruction part of the amps manual?
No, but to be fair I have not yet seen an amplifier user manual saying "if you want to test this amplifier on a test bench you need to add X or do Y".
Those are operation manual not test manual.

The datasheet for the Merus MA12070 does clearly states this requirements for testing.

Again if you connect a set of regular speakers(with woofer, tweeter and crossover) to the amplifier this issue does not happen. The only issue I'm aware of it's when you try to bi-amp or connect to tweeter directly. In that case the tweeter coil inductance might not be enough, therefore noise and distortion is present.

Big screw up from SMSL just to save some cents on the amplifier. But is not the end of the world.

I'm just trying to let people know the truth about this amp, and then it's up to them decided based on facts if this amplifier is adequate to them or not. And not based on a inadequate test which does not tell the whole story about this amp.

But you know what, let's invite people to try another very similar amplifier, the Sabaj A10a. It is an hybrid between the SA300 and the A100. Internal high quality Power Supply, nice film capacitors on output filter, nice power supply bypass capacitors, Digital Volume control and I believe it also uses the OPA1678 opamp. No BT of USB inputs. All for $136, or its big brother Sabaj A20a for $205 The only problem for me it's the form factor and the blue LED display.
Is it worth the extra $46 for the A10a,or the extra $115 on the A20a? well it's up to the people to decide.
The SMSL DA-9 for $250 is another option (better form factor) and the same performance and features as the A20a, but more expensive. There is always a trade off.

If you want something better then be ready to pay more. I'm just highlighting those rare exceptions (amplifiers with a low price but performance comparable to more expensive amps).

Right know I'm enjoying my favorite music (Classic Rock) on my budget system: SMSL SU-6, SMSL SH-6, FX Audio Tube 01 (heavily modified with new resistors, capacitors, tubes and power supply), SMSL A100 with replaced voltage supply bypass capacitor, it comes with a 1000uF Panasonic capacitor and I replaced with a 3000uF Nichicon UBY, on the heavily modified Jamo C93 II (with new polycaps, resistors, and modified port tubes, speaker basket damping with duct seal and felt pads, and cabinet damping with cotton bathing sheets) and a Mirage S8 sub connected from the A100 sub out.
Yesterday I was listening with my heavily modified Aiyima A04 (all capacitors, inductors, OPA1656 and NP0/C0G MLCC Murata and TDK Ceramic Bypass capacitors on all capacitors and on the opamp voltage pins as well, and a modified 36V power supplied dialed down to 33V and multiple bypass capacitor to smooth the voltage to a 5mV P-P ripple)

I simply enjoy modding, it's on my blood.

I'm planning on doing an A/B test using a Speaker Selector Switch but used backwards. Instead of one input and multiple outputs I can wire it to be multiple inputs and one output to speakers.
 

dr_mick51

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Saying that this amp is bad because It performed poorly on a inadequate test setup is like saying a Ferrari is slow because it does not go fast during rush hour in downtown. Just change the test setup and the results will change as well.
Let's agree that the manufacturer could have added those extra chokes for an extra dollar or two and all this could be avoided, and right now we would be talking about how good this performs for its price.
But I cannot agree to say this is a bad amp just because it performed bad during a test that was not technically adecuate.
I trust measurements when they are properly conducted but above all, I trust my ears.
I prefer 100 times an amplifier that measures had but sound good, than the one than measures good but sounds bad.
Signing out for today.
 
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TheBatsEar

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Saying that this amp is bad because It performed poorly on a inadequate test setup is like saying a Ferrari is slow because it does not go fast during rush hour in downtown. Just change the test setup and the results will change as well.
I understand your position, but don't share it.

  1. The measurement was done like all other measurements using industry wide methods. It can be compared directly to any other tested amp. If the measurement setup would be changed per device, to get better numbers, we couldn't compare them.
  2. The device behaves differently depending on the load, which is an engineering mistake. Best to move on and buy something else, since other manufacturers did not make this mistake.
  3. Nothing of this load dependent behavior was mentioned in the manual. It probably means the manufacturer never measured the device with methods that are industry wide in use.
  4. The fact that there is mention of this behaviour in one components datasheet doesn't help, the datasheet wasn't delivered with the product nor a note which component was used.
  5. You could make the case that the method to measure ALL amps is flawed, because it doesn't simulate a real speaker. I would support this, and i would like to see everyone agree on the same speaker simulation load.

Let's agree that the manufacturer could have added those extra chokes for an extra dollar or two and all this could be avoided, and right now we would be talking about how good this performs for its price.
Yes. Sadly, the manufacturer took a shortcut to profits, and we are talking about this shortcut now. There is a lesson to be learned.

But I cannot agree to say this is a bad amp just because it performed bad during a test that was not technically adecuate.
I agree, for playing music from an analog source (remember that BT and USB are fuarked as well) it's an adequate amp.
I wouldn't buy it, plenty of options that aren't flawed at all.

I prefer 100 times an amplifier that measures had but sound good, than the one than measures good but sounds bad.
I don't think the second situation is a thing, Dr. Mick :).
 

dr_mick51

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I understand your position, but don't share it.

  1. The measurement was done like all other measurements using industry wide methods. It can be compared directly to any other tested amp. If the measurement setup would be changed per device, to get better numbers, we couldn't compare them.
  2. The device behaves differently depending on the load, which is an engineering mistake. Best to move on and buy something else, since other manufacturers did not make this mistake.
  3. Nothing of this load dependent behavior was mentioned in the manual. It probably means the manufacturer never measured the device with methods that are industry wide in use.
  4. The fact that there is mention of this behaviour in one components datasheet doesn't help, the datasheet wasn't delivered with the product nor a note which component was used.
  5. You could make the case that the method to measure ALL amps is flawed, because it doesn't simulate a real speaker. I would support this, and i would like to see everyone agree on the same speaker simulation load.


Yes. Sadly, the manufacturer took a shortcut to profits, and we are talking about this shortcut now. There is a lesson to be learned.


I agree, for playing music from an analog source (remember that BT and USB are fuarked as well) it's an adequate amp.
I wouldn't buy it, plenty of options that aren't flawed at all.


I don't think the second situation is a thing, Dr. Mick :).
Ok dude, whatever you say.
Don't buy if you don't want. Nobody is forcing you. I'll keep giving the same opinion. This amplifier is very good for its money.
And because I like modding my audio equipment I'm going to share the last thing I did. I replaced all the 10uF 16v on the audio path with Nichicon UCQ 10uF 16v, these are Nichicon SMD capacitors for Audio applications introduced in 2018.
Man, for little more than $0.60 for each of those 6 capacitors this mod totally worth it.
This amplifier now sounds way better than expected. The original capacitors were holding back this amp more than what I thought.

I really recommend this little amp to all the adventurous people who like me love modding and get better performance for little money, and not for the people that keep stock and don't want to take advantage of the full potential of the equipment.

Again it all about people's taste. Nobody is wrong or right. If you like something then you like it, if you don't then you don't.

If somebody has a better recommendation on this price range, then I welcome that person to share it with the community.

For under 100 dollars my recommendation goes to Aiyima A04/07 and SMSL A100.

For under 150 dollars it would be Sabaj A10a.

Peace, out

Edit: I totally forgot about the Topping PA3s. I also recommend that amplifier, and also measures well.
 
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Zek

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This is the answer to a similar question for the new Sabaj A1 amplifier:

Screenshot 2022-05-20 at 20.57.50.png
 

dr_mick51

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This is the answer to a similar question for the new Sabaj A1 amplifier:

View attachment 207791
Yes, the new Sabaj A1 is pretty similar to the SMSL A12. And their answer to the LC filter seems pure BS. We know that if we measure any Merus MA12070 based amplifier without those inductors the result measurements won't be good. But not audible under real life usage (speakers not in bi-amping)
41ot4SRer6L._SL1000_.jpg

51xuZj4zPJS._SL1500_.jpg




This is the only partial picture I've seen of the Sabaj A1
14952e59-d513-4477-9037-27f3e107ac5e.__CR0,0,300,300_PT0_SX220_V1___.jpg

And this is the SMSL A12:

1653074539645.png




1653074444987.png

Note the same SMD 470uF 25V capacitors around the chip on both amps, and the no presence of output inductors on the back of PCB of A12, and your attachment confirms the Sabaj A1 does not have those inductors neither.

It's a shame, I don't know why they skimp on these chokes. It makes them look bad on measurements when clearly some of them sound very nice depending on the internal Audio Path on the Amp (Coupling capacitors and Opamps).
 

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Zek

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Here is an example where there are inductors and capacitors in the output.

Hdb12302a0404471fb88afef477f61c0cP.jpg
 

dr_mick51

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Here is an example where there are inductors and capacitors in the output.

Hdb12302a0404471fb88afef477f61c0cP.jpg
I've seen that amplifier on Ebay and Aliexpress, but on some forums is said that it has some issues. But some people are modding it to fix the design flaws.

It's incredible that a $26 amp comes with those inductors by $90 don't. Its really a shame.
Yes, I see this amplifier uses Coil wound inductors(the best in my opinion) on the output, but some other amps like the Loxjie A30 use very small smd choke/beads, which also works. You can see an example on the same picture you sent, both (beads and coil wound) have the same inductance 10uH:
1653078596683.png
 

MarcosCh

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Hi,
What would be a well regarded alternative to this but with remote?
That is:
Small
Very cheap
Usb input
Remote
Volume knob and screen is a plus

I have seen other smsl amps but they don't afford many hits when searching here...
 

RandomEar

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Hi,
What would be a well regarded alternative to this but with remote?
That is:
Small
Very cheap
Usb input
Remote
Volume knob and screen is a plus

I have seen other smsl amps but they don't afford many hits when searching here...

Untested here (because it's brand new), but the DA-6 might fit the bill.
 

MarcosCh

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Untested here (because it's brand new), but the DA-6 might fit the bill.
Yeah i saw that one, looks pretty amazing for the price, but no usb input, that is a must for the use i want to give it.

PS: ended up going Loxjie a30, costed 60 eur more but seems like the safest bet.
 
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