SMSL A300 Stereo Amplifier Review

[saberger0357]

I've had no issues with master/slave, and since I'm using a preamp with remote, I just set the amps gains and use the pre to adjust system gain.

What I'm wondering does using the master-slave result in more potential output/watts, then a bridged dual mono?

 

[ampguy]

May I refer to the initial thread about that amp to find answers, https://www.audiosciencereview.com/forum/index.php?threads/new-smsl-a300-btl-class-d-power-amp.34607 , it's been discussed starting somewhere around the middle of all posts. In short: master-slave wasn't recommended as overly useful, better use one remote control and just feed devices monaural with no interconnection. Since both devices will respond in parallel to any command from remote control - and will do that reliably.

Have been following the thread for a long time, you might note I've also contributed to it. I find the main/secondary BTL method to work fine, using a single remote for the main amp. See my last post there. Works great for me.

 

[ampguy]

I've had no issues with master/slave, and since I'm using a preamp with remote, I just set the amps gains and use the pre to adjust system gain.

What I'm wondering does using the master-slave result in more potential output/watts, then a bridged dual mono?

As long as you're using the correct inputs, speaker outputs, and ensuring BTL mode is enabled on both amps, you should be getting 400wpc in mono BTL mode @ 1% THD @ 4ohms per Amirs measurements, the difference is that it's not known if the BTL output of the main amp is only carrying the secondary signal.

What Toku and I have observed differently in the A300 thread is he has simply set both amps to BTL mode, but I think using L inputs for Amp 1 and Amp 2 and I guess that works for some. I've just followed the directions, and the remote for my main amp (with the L/R inputs from source, and BTL to 2nd amp L input) controls both channels fine, including phase.

 

[saberger0357]

As long as you're using the correct inputs, speaker outputs, and ensuring BTL mode is enabled on both amps, you should be getting 400wpc in mono BTL mode @ 1% THD @ 4ohms per Amirs measurements, the difference is that it's not known if the BTL output of the main amp is only carrying the secondary signal.

What Toku and I have observed differently in the A300 thread is he has simply set both amps to BTL mode, but I think using L inputs for Amp 1 and Amp 2 and I guess that works for some. I've just followed the directions, and the remote for my main amp (with the L/R inputs from source, and BTL to 2nd amp L input) controls both channels fine, including phase.

Thanks.

So are you saying that while mono BTL should be 400 wpc, it is not known how many wpc we get if we used the BTL mode that you use and I prefer, using the BTL-R on the master connected to the L input of slave? Or should it be the same? While from a sonic perspective it really doesn't matter, it would be helpful for me to know if there is any advantage other then ease for some in using the remote to connecting without the BTL-R connection. I believe Toku indicated he thought the amps sounded better without the connection, but I prefer connecting that way.

 

[ampguy]

Thanks.

So are you saying that while mono BTL should be 400 wpc, it is not known how many wpc we get if we used the BTL mode that you use and I prefer, using the BTL-R on the master connected to the L input of slave? Or should it be the same? While from a sonic perspective it really doesn't matter, it would be helpful for me to know if there is any advantage other then ease for some in using the remote to connecting without the BTL-R connection. I believe Toku indicated he thought the amps sounded better without the connection, but I prefer connecting that way.

I think we may be doing it the same. Here's how I have my 2 setup:
***
Hooked up my 2nd A300 for dual mono. Really enjoying it. It's actually very simple:

Power Both amps OFF.

Master A300 takes inputs to L/R of IN1 from DAC or other source RCA source pair.

Slave uses same Menu and Input settings, set BTL on both.

Key thing: From the Master A300, use a single RCA cable from the BTL output on the Master to the Slave A300's L IN1 input. Leave the Slave's BTL and IN1 R disconnected.

Connect the L/R speaker leads to each amp, per the diagram in the Manual.

Double check everything. Power both on, ensure Input is properly set, and both are set to BTL. Ignore the Volume numbers, just ensure the slave's volume is higher than you plan to set the master volume. Run some tests for L/R, Phase, test tones, get it all setup.

Enjoy!
***

The alternate way from that other thread is to keep BTL set on both, and I presume using same speaker outputs for both speakers per manual, but instead of using the BTL RCA from main to 2nd, and L/R input completely to main amp, is to use L input of IN1 on both main and 2nd, but 2nd has the "Right" input. I would *think* that still gives BTL bridged properly, but without schematic, I do not know what the BTL wire from main carries, other than 2nd input (e.g. R input from main).

 

[saberger0357]

I think we may be doing it the same. Here's how I have my 2 setup:
***
Hooked up my 2nd A300 for dual mono. Really enjoying it. It's actually very simple:

Power Both amps OFF.

Master A300 takes inputs to L/R of IN1 from DAC or other source RCA source pair.

Slave uses same Menu and Input settings, set BTL on both.

Key thing: From the Master A300, use a single RCA cable from the BTL output on the Master to the Slave A300's L IN1 input. Leave the Slave's BTL and IN1 R disconnected.

Connect the L/R speaker leads to each amp, per the diagram in the Manual.

Double check everything. Power both on, ensure Input is properly set, and both are set to BTL. Ignore the Volume numbers, just ensure the slave's volume is higher than you plan to set the master volume. Run some tests for L/R, Phase, test tones, get it all setup.

Enjoy!
***

The alternate way from that other thread is to keep BTL set on both, and I presume using same speaker outputs for both speakers per manual, but instead of using the BTL RCA from main to 2nd, and L/R input completely to main amp, is to use L input of IN1 on both main and 2nd, but 2nd has the "Right" input. I would *think* that still gives BTL bridged properly, but without schematic, I do not know what the BTL wire from main carries, other than 2nd input (e.g. R input from main).

Yes that's how I'm doing it.

And I'm sorry to keep asking the questions, but what I'm still trying to understand is the wpc per Amir's measurements the same with either connection?

 

[ampguy]

Yes that's how I'm doing it.

And I'm sorry to keep asking the questions, but what I'm still trying to understand is the wpc per Amir's measurements the same with either connection?

I would guess yes. Because Amir only had a single unit, so he set it to BTL mode, used the proper speaker connections, and put in some source to I presume the L input of pair IN1 or IN2 for his test. He had no way or need to use the BTL RCA output on his single A300. So yeah, with BTL mode set, and proper outputs (per manual) of the 4 speaker taps, you should be getting 400 watts mono.

 

[saberger0357]

Thanks!

The more I listen to them the more I like them. They are really perfect for the gear that I'm using them with. Whatever deficiencies Amir's tests uncovered are not noticeable to my ears in my set up.

And just to confirm, if I'm bridging a pair of amps driving 8 ohm speakers, the amps react as if they're 4 ohms. So the 400 watts at 4 ohms would be the correct figure, as opposed to 219 at 8 ohms. Do I have that right?

Hopefully folks who decide to dump these amps because of the poor specs flood the market. Would love to pick up a couple more at a discount

 

[ampguy]

Thanks!

The more I listen to them the more I like them. They are really perfect for the gear that I'm using them with. Whatever deficiencies Amir's tests uncovered are not noticeable to my ears in my set up.

And just to confirm, if I'm bridging a pair of amps driving 8 ohm speakers, the amps react as if they're 4 ohms. So the 400 watts at 4 ohms would be the correct figure, as opposed to 219 at 8 ohms. Do I have that right?

Hopefully folks who decide to dump these amps because of the poor specs flood the market. Would love to pick up a couple more at a discount

@amirm or someone can correct me, but I think if the bridged amp sees the 8 ohm load, you're only getting the 218/219W per side (amp). My speakers dip down to 3.9 ohms or something, depending on frequency, so I believe I may be hearing the high shelf deficiency measured, which is actually a preference I have had in past Roon EQ and Puffin phono preamp DSP settings, which may be why I like it at flat settings. But this shouldn't be anyone's "reference" amp. For that, get the Fosi V3 for $95

 

[saberger0357]

@amirm or someone can correct me, but I think if the bridged amp sees the 8 ohm load, you're only getting the 218/219W per side (amp). My speakers dip down to 3.9 ohms or something, depending on frequency, so I believe I may be hearing the high shelf deficiency measured, which is actually a preference I have had in past Roon EQ and Puffin phono preamp DSP settings, which may be why I like it at flat settings. But this shouldn't be anyone's "reference" amp. For that, get the Fosi V3 for $95

A little research confirmed that a bridged amp does see half the speaker load. So the bridged A300's driving 8 ohm speakers are operating at 4 ohms.

Your speakers being 4 ohms, will cause the amps operating at 2 ohms. That's the main reason I didn't use them with my 4 ohm speakers, although when I did they were ok, but I didn't drive them very hard. I bought the V3 to run with those speakers and added the 48V PSU for extra juice.

 

[grogi.giant]

iiwi reviews said he preferred this one over PA5.
https://iiwireviews.com/smsl-a300-great-integrated-amplifier-just-200/
"Topping PA5 was an improvement over the DA-9 to my ears, bringing more details and clarity but it was also leaner and more analytically inclined. A300 pushes the soundstage a bit closer to the listener, so you might say that PA5 has a deeper soundstage. That said, every tone sounds more present in the room, more palpable, and simply more lifelike with A300, while not losing any of the fine details. Once again, I find A300 to be the winner and the more enjoyable listen of the two."

PA5 is based on the same chip as Aiyama A07

I have seen a few DACs reviews to know his videos, although very nicely made, have only entertainment value. There is absolutely zero merit to them.

 

[grogi.giant]

The AL200 looks very promising but I miss the subwoofer output. I am not entirely convinced about the A-S701. Even the opinions of users tend to the fact that it lacks depth and impact and the brightness of the sound comes to the fore.
I really like the sound of the A-30 and wish its successor the A-40 had SW

This is nonsense.

 

[Bleib]

I have seen a few DACs reviews to know his videos, although very nicely made, have only entertainment value. There is absolutely zero merit to them.

I don't quite think the same, usability, remote and other aspects can be brought into discussion in subjective reviews... just like in this comment section

 

[grogi.giant]

I don't quite think the same, usability, remote and other aspects can be brought into discussion in subjective reviews... just like in this comment section

That's a fair point. Although this you were quoting the 'to my ear performance' metrics...


What really got me was claims that some DACs are more rhythmic... Wtf?!

 

[dudewithcans]

What really got me was claims that some DACs are more rhythmic... Wtf?!

yeah, i mean... he is an entertainer, like all those other reviewers. whether he gets paid for those reviews, or not, is irrelevant in the first place as its a purely subjective review, and (mostly) no (own or 3rd party) measurements are taken into consideration.
as we all know, in _such_ reviews, claims regarding the sound are made purely on subjective perception - and theres absolutely nothing wrong with that.
just like with ppl that claim god exists, and ppl that claim god does not exist, and of both exist ALOT. =)

if one of those reviews perceive the sound of a device to sound in this or that way different from one another, its absolutely ok to broadcast this OPINION to the world... crucial is FOR A VIEWER of those channels is, to understand this and TO INTERPRET the given "information" correctly.
sure you can make up your mind or buying decision based on such "claims" regarding the sound... whether this makes sense, or not, or to rely on measurements (wich can also be wrong, or, for the human sense of hearing, meaningless) and data, or not, is purely up to the person...

and what he essentially says is:
HE prefers PA5 over DA-9 - is an opinion. should this be relevant to you? -> no, as it does not mean YOU prefer it.
does it make sense in general? YES. PA5 is regarding measurements simply the better amplifier.
further: "Topping PA5 was an improvement over the DA-9 to my ears" -> it is technically aswell. makes sense.
further: subjective blabla - you can BELIEVE IN (!) that, or not.
further: HE prefers the A300 over the PA-5 - is an opinion. should this be relevant to you? -> no, as it does not mean YOU prefer it.
does this make sense in general? yes. why? even though A300 measures worse then PA-5, this does not mean it MUST sound worse in general TO YOU. theres ALOT of ppl that actually prefer the sound of tube amplifiers over solid state, and all of those devices measure ALOT WORSE then most solid state... still ppl prefer it. NOTHING wrong with that.
do I think the A300 ist a good amplifier (by my standards) after having 2 samples of this at home? no.
do i think it SOUNDS "good" to me? yes i do. =)

 

[Elvom]

Ive had this unit for about two weeks, got it as a backup as my cambridge AXR100 was having protection issues and its on maintenance right now.

Theres no tweeter hiss at all, maybe shoving my ears on the tweeter i can barely hear something and also theres no PC usb noise at all (cambridge was picking up LOUD GPU noise fan like a helicopter) both using the same smsl m300mk2 DAC, i had to get a USB isolator with the Cambridge but with the SMSL A300 theres no need for it, also it barely gets warm.

Sound quality wise i think both just sound the same, maybe the cambridge had a hair fuller bass, and both running a KEF R3 pair, sub out is just very useful and the option to use HPF works really well to integrate a sub also the EQ settings works, especially the Loudness effect for low level volume.

Im quite happy with this little amp: sub out, great sound quality, dead quiet, small size, runs cool and its quite cheap.

 

[ampguy]

Ive had this unit for about two weeks, got it as a backup as my cambridge AXR100 was having protection issues and its on maintenance right now.

Theres no tweeter hiss at all, maybe shoving my ears on the tweeter i can barely hear something and also theres no PC usb noise at all (cambridge was picking up LOUD GPU noise fan like a helicopter) both using the same smsl m300mk2 DAC, i had to get a USB isolator with the Cambridge but with the SMSL A300 theres no need for it, also it barely gets warm.

Sound quality wise i think both just sound the same, maybe the cambridge had a hair fuller bass, and both running a KEF R3 pair, sub out is just very useful and the option to use HPF works really well to integrate a sub also the EQ settings works, especially the Loudness effect for low level volume.

Im quite happy with this little amp: sub out, great sound quality, dead quiet, small size, runs cool and its quite cheap.

Enjoy, but note that we may be kicked out of the budget audiophile club for liking this amp with it's dreadful specs!

 

[saberger0357]

Enjoy, but note that we may be kicked out of the budget audiophile club for liking this amp with it's dreadful specs!

Let's start our own club. The Dreadful Specs!

 

[dudewithcans]

Ive had this unit for about two weeks,

Theres no tweeter hiss at all, maybe shoving my ears on the tweeter i can barely hear something

i find that more than incredible on an 87dB KEF R3...
it must mean (if your hearing is in good condition) that both of the A300 units i had (different retailers btw), had serious quality issues and should have never seen the market in the first place. good and useful quality control seems to be an alien concept for SMSL then, what else should i make of this...
and i say this again: i would REALLY LIKED to use this amp... besides the noise issue on my units, i though it did sound good and i like it functionwise aswell.

 

[grogi.giant]

i find that more than incredible on an 87dB KEF R3...
it must mean that both of the A300 units i had, had serious quality issues and should have never seen the market in the first place.

Yeah, it shows that even though the amplifier might be ok, the QC is absolutely dreadful.

That could be acceptable if absolutely hassle free customer service network was in place and you'd get a replacement unit next day. I don't think we're there...

I have recently won a bag of chips in work raffle, I feel my luck is used up for at least 5 years. I'll pass.