SMSL SA300 / Infineon Class D

[Moosi]

Only got my ears to measure, they are 34 year old ears without any issues. Was considering the amp to be a little low on the power side. Got it to peak to about 10watts (measured at the wall-plug) which was about volume 44 of 60 with my 8ohm speakers. That was really loud, on a level where I could risk my neighbors going nuts when playing over longer periods. Loud enough for me not to feel the urge of having to push it any further.

besides: I have read quite a lot about the amp before buying it. Not a single note have I found about people complaining it isn't playing loud enough. If someone wants to feel safe, you can get a 26V power supply and get about 10% more wattage out it.

 

[Vladetz]

I'm using da-8s which has same amp chip and never go more than 35 out of 60 in 18sq meters room with 88db speakers

 

[boselover61]

I'm using da-8s which has same amp chip and never go more than 35 out of 60 in 18sq meters room with 88db speakers

I have to go to 47 to get some decent volume out of a 86db

 

[M1ke]

Depends on what you want. On my 8 ohmers, the AS300 is more than sufficient as a Desktop amp in a small room. If you want to listen loudly (>80db) in a medium to large room, you'd probably be better off with an "Aiyima A07" which has about double the power of the SA300 if paired with a powerful 48V power supply, yet costs only around 50 bucks. Audio quality seems to be on the same level for what I know. When buying the A07, look for the newer version with LM45xx OP-AMPs.

AS300 -> 30W@8Ohm (38W@6Ohm)
Aiyima A07 -> 55W@8Ohm (68W@6Ohm) /both tested numbers from reviews here on audioscience @<1%THD

With a 6 Ohm speaker, I would multiply those numbers by 1.25.

@Moosi thanks for the advise. Do you use a DAC connected to AS300? Aiyima A07 option has no Bluetooth.

 

[Moosi]

Do you use a DAC connected to AS300?

not yet, still using the internal USB-DAC. Planning on buying one soon tho. Not that the sound bugs me, but I want to hear myself if there is a difference as some have supposed.

 

[Melvinne]

Any thoughts on USB cables for this amplifier?

I have tried a USB-C -> Micro USB and would get tiny pop/clicks during playback.
I then tried a USB-A -> Micro USB and also got some static pops (same as above).

Using a super cheap USB-A -> Micro USB that came with headphone to charge them and no issues.

I definitely don't believe in the "AudioQuest" factor, that's crazy spend for a digital cable IMHO. Curious what others have found works for them.

 

[Feesh]

not yet, still using the internal USB-DAC. Planning on buying one soon tho. Not that the sound bugs me, but I want to hear myself if there is a difference as some have supposed.

In my experience getting a 100€ DAC makes a big difference.

A much bigger soundstage and a lot more depth.

 

[aebln]

Hello,
Original one is a complete crap power supply, whatever you can buy will be better than original one.

I second that. Ordered an SA300 this week - the power supply was dead on arrival. Hope the Amp is working though. Hifi-Express immediately offered 15$ refund for the dead supply. It clearly isn't worth even that. Will replace the PSU with an LRS-200-24 (32€ on Amazon). Teşekkür for this insight, @fluxcapacitor.

 

[whazzup]

Any thoughts on USB cables for this amplifier?

I have tried a USB-C -> Micro USB and would get tiny pop/clicks during playback.
I then tried a USB-A -> Micro USB and also got some static pops (same as above).

Using a super cheap USB-A -> Micro USB that came with headphone to charge them and no issues.

I definitely don't believe in the "AudioQuest" factor, that's crazy spend for a digital cable IMHO. Curious what others have found works for them.

Sharing my own experience in another thead:

With my current old dodgy PC (i5 2400, can't remember the motherboard), I will only get stutter free audio with the 'native' usb ports (the ones closer to the corner, the ones higher up if your PC is upright). I believe the additional ones in the middle uses a different 3rd party chipset, so perhaps has a higher latency or something. I see this with all my usb audio devices (Topping D10, Xonar U7, Creative SXFi). When I use the 3rd party chipset ports, I'll see stuttering that goes on and off, more likely to occur when there are higher levels of system processes working.

 

[Melvinne]

Sharing my own experience in another thead:

Interesting. I wonder if that’s a setting I can adjust in the Audio MIDI Setup (MacOS) to adjust the buffering level. It was originally working fine in the USB C (Thunderbolt actually) port with a USB-C to Micro USB cable, but then it started with the little tiny static pops. It doesn’t sound like stuttering, but like I said, cheapo cable works fine via standard USB-A port so I’m fine for now.

 

[Moosi]

Will replace the PSU with an LRS-200-24

Why the LRS-200? I was thinking of the LRS-100 which has at least double the power of the SMSL PSU. Is there any advantage of going 4x the power? I would assume a 200w PSU would be hugely over the top for this amp. I see no benefit over the LRS-100, the LRS-200 is even slighty less efficiant.

I dont know about switching power supplies, but with linear power supplies, the THD gets worse the less you max-out your PSU.

 

[aebln]

I was thinking of the LRS-100 which has at least double the power of the SMSL PSU.

I wondered myself, actually. Since the SA300 is so power efficient, I was asking myself, why the S.M.S.L PSU - it's 6,75A @ 24V = 162W. Manufacturers usually try not to spend a cent too much in production if it isn't necessary. If a weaker PSU was sufficient they'd have saved some pennies there for sure. Anyway, since I don't know enough about the matter I decided to be better safe than sorry.

 

[Moosi]

I thought it has 2.1A but that is the only the input. Well, I measured it and got it to about 10W max. at reasonable loud volume. The 162W is probably only because the theoretical max. output -on paper- of the amp is being described as 2x80W (@4ohm/10% THD) and therefore would need a 160W supply. However these numbers are silly and far from reality. If(!) you could drive the amp to about 160W total consumption, something extraordinary would have happend long before that. Either your ears will have imploded or the amp will have turned into a firebolt ascending into space.

The max. output as measured in reviews and with reasonable THD (<1%) is about 55W (4ohm) and 32W(8ohm). With the MeanWell LRS-100-24 and a 26V supply, those numbers might stretch to 60/35. Still we are far from 160W. If you stretch it to <5% THD those numbers might rise to about 105/60 or something, but you would have to play it on a volume level that is not applicable under most circumstances to even reach a THD higher than 5%.

If you are near def or your living room has the size of a concert hall, this amp is not suited.

 

[aebln]

The max. output as measured in reviews and with reasonable THD (<1%) is about 55W (4ohm) and 32W(8ohm). With the MeanWell LRS-100-24 and a 26V supply, those numbers might stretch to 60/35.

As I see it, instead of advertising this amp's power efficiency they opted for "our customers will compare it with other similarly priced amps and ours will lose because it needs less W". Your reasoning is logical @Moosi. I changed my order for a LRS-100-24 it's cheaper and smaller and probably more efficient as well. I rarely turn up the volume, so it should be more than enough for my 6 ohm speakers.

 

[Moosi]

There is a certain threshold at which you will have to double the power in watts to get only a 3db increase in volume. That threshold I believe is being defined by your speakers. If your speakers are efficient 8ohmers as my KEF Q150, they might play to like 86db and consume only 1-2W with this amp.

KEF Q150

• 8ohm / 86db efficiancy
• 10-100W max. (106db max.)

However, if you want to go from 86db to 89db all over sudden your power must double. 1-2W -> 2-4W (89db) -> 4-8W (92db) -> 8-16W (95db) -> 16-32W (98db) -> 32-64W (101db) -> 64-128W (104db)

In order to get the maximum sound out of my speakers (106db) I would have to put something between a real ~90-150W into them. That would be too much for the amp, it would distort the sound heavily at that level and shut off itself eventually, regardless of how powerful the PSU is. Besides, playing a 90 db already is really, really(!) loud for any person with normally developed ears. As I said, I can't measure soundpressure in db, but I can measure Watts and therefore predict a soundpressure range. With a measured 5-10Watt range I was listening at really loud volumes, probably >90db. For a desktop amp you would not need any more. My every day music/youtube/videogame output is between 1-3W.

Those watt numbers thrown around in the industry are silly as fuck. Those hifi folks have to troubles selling some grandma a 800W amp to play country songs on the kitchen table. She probably could run a nightclub with an amp like that. PSU's with high power output are yet cheap, just a few bucks price difference between a 100W and a 200W PSU. People without knowledge however do get impressed by higher numbers, even if they would literally make them def when being applied to their speakers.

 

[farundrpar]

Hi all, does anyone has both the AD18 and SA300? I have both units and testing them out. I am driving Emotiva B1+ for a small office. It seems using both bluetooth and USB (from an iPad Pro) that i am getting way more power out of the AD18. Wondering if i have a faulty SA300 as i wouldn't think there would be that big of a difference. On the SA300, i constantly need the volume at 30 or greater, where the AD18, i am getting the same volume at about a 15 level.

I liked the SA300 for the RCA input for my Yamaha CDs300.

anyone else having this experience?

 

[Moosi]

Maybe it is the crappy PSU. Have you tried using the AD18-PSU with the AS300?

I have noticed that volume differs a lot depending on the source. Some flacs play a lot louder than others by default. Some games I have to put volume to 36, some games to 26 to have roughly the same volume.
Make sure you have allowed your USB-plugged device to run in exclusive mode (windows audio-settings).

 

[farundrpar]

Maybe it is the crappy PSU. Have you tried using the AD18-PSU with the AS300?

yes, using the exact same PSU. All other cables are identical as well.

 

[Moosi]

are you running both amps in "direct mode"? Some EQ-adjustments will alter the volume too.

 

[farundrpar]

are you running both amps in "direct mode"? Some EQ-adjustments will alter the volume too.

Yes, both are in direct mode. Unless i am missing some setting, they are setup exactly the same way.

Now that i am running them again, the AD18 is really pumping out the music. So much so that when I have the Yamaha CD-s300 plugged into the AUX - analog in (to lesser extent USB with iPad), i almost can't control the volume - level 2 (out of 60) is a comfortable listening level (maybe a little lower than i would want), and that is as low as it goes. Level 10 is really loud.

I wonder if it does have to do with the power supply - when i go and switch the power supply into the actual AD18 unit, there have been a couple small sparks at the connection point ( i guess i should unplug from the wall before i plug power supply into the unit). Now i am wondering if its the AD18 that has an issue of too much power? that would seem odd, but I admittedly am not an expert here at all. It doesn't get too hot or anything like that.