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New SMSL A300 BTL Class-d Power Amp

Toku

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to me the only reason i avoided the A20a is the reports of units dying very quickly... I mean look at the amazon and various web reports

and right now their webpage has gone:

Service Unavailable​


HTTP Error 503. The service is unavailable.

the build quality of the case is obviously there and you lose the screen but it comes down to... do you put up with the unit suddenly dying or just buy an A300 and let it just work. I leave mine all 24/7 and its been fine.
The server seems to be down.
The same thing happened the other day.
 
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to me the only reason i avoided the A20a is the reports of units dying very quickly... I mean look at the amazon and various web reports

and right now their webpage has gone:

Service Unavailable​


HTTP Error 503. The service is unavailable.

the build quality of the case is obviously there and you lose the screen but it comes down to... do you put up with the unit suddenly dying or just buy an A300 and let it just work. I leave mine all 24/7 and its been fine.
Mine (I own three pieces of it) are the "older" A20a(s) from 2020. I "just" had to replace all three PSU boards which initially came faulty by design. Apart from that these work flawlessly. Due to ultra low power consumption you can leave them powered on without "making plans" about listening and-or just idling. https://www.amazon.com/-/en/Balanced-Amplifier-Receiver-Infineon-MA12070/dp/B091YJC9RT
 

Netherspark

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My brand new A300 is producing a loud high-pitch whine through the speakers, along with unbearably loud hiss.

I have no idea what's causing the hiss. Even with the volume at zero and no inputs connected the hiss is still audible 6 feet from the speakers. My old class A/B Onkyo amp only had audible hiss with your ear up against the tweeter.

I think the whine seems to be driven by interference from the LED screen, because the tone and volume of it changes based on the content and brightness of the screen. Has anyone else noticed this?
 

Tegyr

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I think the whine seems to be driven by interference from the LED screen
Thanks for the hint @Netherspark , I can confirm that the whine is connected to screen brightness.

With my Elac DBR-62 it is very annoying at default brightness and pretty much completely gone at the lowest brightness setting... definitely seems to be some design flaw.
Maybe @SMSL-Mandy can comment on it, is it a known issue?

All that remains now is a fair amount of white noise but at normal volumes it's ok.

Also as someone else has pointed out the ground pin is not connected but there's an isolating plate under the PSU (not on the top of the case though), and the incoming power cables rest against the top of the metal case but there's also additional heat shrink in that area...

It's a bit of a shame as otherwise it's probably the best sounding Class-D amp that I have tried so far.



a300.jpg
 
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dr_mick51

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My brand new A300 is producing a loud high-pitch whine through the speakers, along with unbearably loud hiss.

I have no idea what's causing the hiss. Even with the volume at zero and no inputs connected the hiss is still audible 6 feet from the speakers. My old class A/B Onkyo amp only had audible hiss with your ear up against the tweeter.

I think the whine seems to be driven by interference from the LED screen, because the tone and volume of it changes based on the content and brightness of the screen. Has anyone else noticed this?
Fortunately, I don't have that issue. I've tried changing the LED brightness and it does not increase/change noise.
I can only hear some noise on my speakers at 45 and beyond on the Volume and my ear at 4 inches from tweeter.

Maybe the ground issue can be fixed by adding a wire from ground pin to any of the ground screws/points?:
Ground.jpg


Will this also fix the noise your are hearing?
 

Netherspark

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Fortunately, I don't have that issue. I've tried changing the LED brightness and it does not increase/change noise.
I can only hear some noise on my speakers at 45 and beyond on the Volume and my ear at 4 inches from tweeter.

Maybe the ground issue can be fixed by adding a wire from ground pin to any of the ground screws/points?:

Will this also fix the noise your are hearing?
Sadly the hiss and whine are audible at any volume.

I gave it a try but adding the earth wire didn't make any difference. Would a ground issue cause excessive hiss like this?

Luckily this unit came from Amazon so it's easily returned. I have another one coming from Hifi Express, so I can compare the two when it arrives but it's going to be difficult to return that one because the idiots sent it from China even though I chose UK shipping on the order...

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
UPDATE: The other A300 came today. It's exactly the same - the same hiss and the same whine, plus this one has a warped chassis and a dodgy dial....

I am not impressed.
 
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Feesh

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Hello everyone!

I've had both the AO200 and A300 at home for testing and they come with different remotes.

Did SMSL start making different remotes for DACs/Amps ? Have they gone away from the A*B*C system?

Already having a SMSL sanskrit 10th mkII adding a 2nd remote is a real nuisance.
 

pbc

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Yes and no in my opinion. The A300 has slightly more power but I prefer everything else about the AO200. The functionality of the user menu is much better as well as the build. Also the AO200 had dual Infineon MA12070 chips vs 1 Infineon MA5332M chip. I’m not sure how much of a difference that makes but the AO200 is 80+ dollars more and feels like it should be. I currently have 2 A300’s in a mono block configuration and that sounds incredible for the money. Plenty of dynamics and headroom to drive any speakers. But if we were comparing 1 AO 200 versus 1 A300 I might sway towards the AO200 just because of the user experience.
Comparing these two as an amp combined with a Martin Logan Unison (for ARC). When a sub is attached what does the AO200 do for crossover? Seems the A300 has a wonky set of diff filters (100hz to the sub and 50 or 60 to the speakers IiRC?).
 

TonyJZX

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i've had this out with other people in this thread already

here's an excerpt from manual:

THD+N ................................................................................................0.004%
SNR .........................................................................................................103dB
Channel separation ................................................................................... 85dB
Cutoff frequency (in high pass mode) ........................................................50Hz

Input Sensitivity / Input Impedance................................................280mV/22kΩ
Output Power
stereo...........................................................165Wx2(4Ω) / 85Wx2(8Ω)
BTL ..............................................................................330Wx1(4~8Ω)
Power consumption...........................................................40W(normal volume)



But as tested the real s/w cutoff is 80hz???
 

pbc

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i've had this out with other people in this thread already

here's an excerpt from manual:

THD+N ................................................................................................0.004%
SNR .........................................................................................................103dB
Channel separation ................................................................................... 85dB
Cutoff frequency (in high pass mode) ........................................................50Hz
Input Sensitivity / Input Impedance................................................280mV/22kΩ
Output Power
stereo...........................................................165Wx2(4Ω) / 85Wx2(8Ω)
BTL ..............................................................................330Wx1(4~8Ω)
Power consumption...........................................................40W(normal volume)



But as tested the real s/w cutoff is 80hz???

Will have to go back through the thread to see ... as I thought there was a difference between the high pass and low pass frequencies, which would seem an odd choice.

Looking at the AO200 manual, there are no such claims around cutoff frequency, so I assume that amp doesn't apply any crossover. Hmm...maybe it doesn't matter as I will be using a Martin Logan Unison with ARC for EQ and if necessary can insert the MiniDSP 2x4 into the chain for high pass/low pass duties.
 

Adis

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How exactly is the preamplification done on this thing? Digitally? I mean, it has an rotary encoder, analog signal undergoes AD conversion or what?
Anyone knows?
Thanks!
 
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TonyJZX

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digitally

the chinese arent gonna spend money on an pwm ADC when they dont need too

low bom costs is everything
 

pbc

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I keep going back and forth on this vs the AO200. All I really need is the amp section, so the 70% more rated wattage is appealing, even if it is "only" 35 watts, and may also use the volume control which both have.

But can get the AO200 at pretty much the same price. For those that own(ed) both, is the SNR difference that noticable?

Also, do either of these things have auto sense to turn on/off vs having to manually use the power switch?
 

Destination: Moon

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I keep going back and forth on this vs the AO200. All I really need is the amp section, so the 70% more rated wattage is appealing, even if it is "only" 35 watts, and may also use the volume control which both have.

But can get the AO200 at pretty much the same price. For those that own(ed) both, is the SNR difference that noticable?

Also, do either of these things have auto sense to turn on/off vs having to manually use the power switch?
If the DA9 and 200 are the same, the sound will be better than the 300. The more I listen to the DA9, the more I am impressed
 

TonyJZX

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to me it depends on how much you value XLR in and the proper colour LCD display rather than the segment clock radio like LED segment display on the A300.

the Ao200 has dual subwoofer out which is an oddness.

I think remote trigger remote on isnt a common thing to the chinese.

BT is the same non name nonsense.
 

pbc

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Yes. I thought that the SW out would relieve my Polk r200s of the bass and improve the overall sound. I wrote about my experience a while back on this thread

Will be using an active subwoofer that has hi/low bass management.
 

pbc

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Looking at the back side of the AO200, the manual isn't clear on the RCA ... says 5 is "remote window" which obviously isn't the case. I assume 5 are the L/R RCA ins and 6 is the two subwoofer outs?

1669401050344.png


1669401145235.png
 
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