Well, so far we haven't seen a Topping PA5 situation with this amp, or pretty much anything else.
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New SMSL A300 BTL Class-d Power Amp
- Thread starter SMSL-Mandy
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ive always said that i use my 300a in a very simple superficial manner... ie. i use a dac or preamp on input 1 or 2 and that's it
i dont use the volume... i just set it to 40-50 as a limiter.... i find at 60-70 it has some noise/hum
but i'm using high performance preamps and dacs that can raise the gain without noise
so i can put up with the occasional screen glitch (just reset it!)
i can leave it on 24/7 and really, what do you expect for that money
i dont use the volume... i just set it to 40-50 as a limiter.... i find at 60-70 it has some noise/hum
but i'm using high performance preamps and dacs that can raise the gain without noise
so i can put up with the occasional screen glitch (just reset it!)
i can leave it on 24/7 and really, what do you expect for that money
The max is 60, isnt it?
grogi.giant
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Your methodology is unfortunately flawed. A A300 with 26/60 might be playing at its 20%, while A30 at 25/60 might be at its 75%.
What you're testing is how linear/logaritmic is the volume control, not how much powerful the amplifier is. Just by studying the spec charts and maintaining decent THD+N (<0.1%):
- MA12070 (A30) reaches ~20W into 8Ohm
- MA5332MS (A300) gives out ~55W into same load.
- TAS5634 in D03 with included PSU (32V) will produce ~30W into 8Ohm.
Testing max power with real speakers in a closed room is suicidal.
Decent engineering. Glitching screen that hums back into the audio signal is not one.
Did you buy from Amazon or from 3rd party seller?
If Amazon, just write to them - you'll get it replaced without much fuss.
If 3rd party seller on Amazon - brace yourself...
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DanielT
Major Contributor
Can someone comment on this regarding the MA5332MS chip?
It doesn't look so good, does it? Page 16 of the data sheet:
I don't know if you can interpret it that way and state that it is best to (only?) use 4 Ohm speakers? Or am I misinterpreting the data and draw the wrong conclusions now?
Edit:
But maybe SMSL compensated for it in some way so the frequency response is straight in the higher frequencies even in 8 Ohm for the A300 BTL amplifier?
It doesn't look so good, does it? Page 16 of the data sheet:
I don't know if you can interpret it that way and state that it is best to (only?) use 4 Ohm speakers? Or am I misinterpreting the data and draw the wrong conclusions now?
Edit:
But maybe SMSL compensated for it in some way so the frequency response is straight in the higher frequencies even in 8 Ohm for the A300 BTL amplifier?
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grogi.giant
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It's not that simple. What this chart really shows is that the amplifier chip is moderately sensitive to the load it drives. There are better designs (exp. various ICEPower or HypeX Ncore - which are almost immune). TPA325x is sensitive too.
This behaviour wasn't really a big issue with class A or class AB amplifiers, they handle various impedances pretty well. D-Class work completely different and employ a low-pass filter post amplification, to attenuate the carrier frequency (the chart clearly shows a steep drop in 20kHz region). There is a caveat: that filter will interfere with the load and the response characteristics of the amplifier changes with different impedance characteristics of the different speakers.
Speakers impedance is not constant. Its magnitude and phase changes with the frequency. The number written on the speaker is the rated impedance - exp. 6Ω. What it really means is that the speaker typically is around 5Ω and sometimes peaks up, to 50Ω or even higher - but roughly you get 6Ω on average. However, there is no information about the phase of the impedance or how the impedance of your speaker looks like in the 5kHz+ region: you might get 10Ω/-45° or 5Ω/45°; and that will dramatically change the response in higher frequencies.
In other words: the same D-Class amplifier behaves completely different with two different speakers, both rated 4Ω.
This inconsistency can be mostly compensated by using PFFB (Post Filter Feedback) - it is correcting the behaviour of the amplifier based on what is coming out of it. I wouldn't bet on this being implemented in the A300 though.
Will you hear the altered response from the amp with your speakers? Most of the time no: the under/overemphasis will be moderate (up to 1dB) and in region we don't hear that well anyway. But in some extreme cases it is noticeable.
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DanielT
Major Contributor
Thank you for the explanation!
It was as I suspected and in line with what I understood previously (generally) about class D amplifiers. You confirmed it. It may also be interesting for others to read what you just wrote.
When we are still on the class D technology. On other forums, or one that I know of, there is more skepticism towards class D amplifiers. The skepticism concerns, among other things, how tests are carried out on class D amplifiers, where it is often complained that too little bandwidth is used during the measurement. Morello is, as I quote, a good EE who designs amplifiers himself, I'll just add.The amp under discussion and Stereophile's measurements of it are this:
Morello:
Note that the measurements on this class-D device are carried out with the low-pass filter (f=25 kHz) Audio Precision AUX-0025 connected between the output of the power amp and the input of the analyzer, which is why all THD measurements are irrelevant above about 6 kHz. I'm surprised Atkinson doesn't limit the graphs to just this.
....
The reason for the measurement procedure is that the analyzer from Audio Precision that Atkinson uses does not handle copious amounts of high-frequency garbage typical class-D spews out. What I object to is that THD data is still reported up to 20 kHz, even though the data is not relevant above 6-7 kHz. It is also clear that many readers of testers do not reflect on this, which is, of course, completely understandable.
.....
THD is a measure of the step nonlinearities - quadratic, cubic and higher order terms in the transfer characteristic. The same terms entail intermodulation distortion. If you want a correct picture of the amp's distortion, the bandwidth when measuring THD up to 20 kHz must be at least 80 kHz, which means that harmonics up to and including order four are included.
The Nad C298 shows high THD at treble frequencies above 10 kHz, despite the fact that the numbers are heavily embellished due to the low-pass filter used in the THD measurement.
(with reservation for inaccuracies via google translate)
Incidentally, I am neutral regarding different amplifier classes.If an amplifier is good, it is regardless of class.
Edit:
Having said that, even the most ardent opponents of class D amps, ..they are only good for subwoofer use, ..seem to be softening now with the development of, as you for example mentioned, Hypex amps.
It is making progress:
Hypex NCx500 Class D Amplifier Review
This is a review and detailed measurements of the Hypex NCx500 NCOREx reference design amplifier. It was sent by the company and kindly assembled by our local expert, @Rick Sykora. As you see the sample is a "monoblock" configuration (one channel) driven by Hypex SMPS1200 switching power...
audiosciencereview.com
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Update. Through Amazon they have offered to have it sent to China for a firmware update which shuts down the screen completely.
So, this means they won't put up a firmware on their website, sadly. But it shouldn't cost me other than time.
I'll send it in.
So, this means they won't put up a firmware on their website, sadly. But it shouldn't cost me other than time.
I'll send it in.
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FWIW- The 1st a300 I got was making a pretty loud hum like noise that started at about 50 on the volume control.
I noticed that if I changed the display brightness the noise obviously changed as well, with the least amount when the display was set to it's lowest brightness.
I returned the to apos for an exchange. It took a month to get the replacement from China.
New unit is dead silent. I like it a lot.
I noticed that if I changed the display brightness the noise obviously changed as well, with the least amount when the display was set to it's lowest brightness.
I returned the to apos for an exchange. It took a month to get the replacement from China.
New unit is dead silent. I like it a lot.
Display glitches were reported early on by me. Please refer to the page below.
I reported this matter to SMSL, but unfortunately it was ignored.
New SMSL A300 BTL Class-d Power Amp
Apart from extra power, any audible benefits that you immediately noticed? Slightly more dynamic tons of headroom to drive any speaker. Even at low volumes of 55-60 db it sounded great. I tried it with speakers ranging from 85 db - 92 db and I’m amazed by how well it drives them all. The A300...
www.audiosciencereview.com
well i think smsl made a economic decision
you bought a $200 china made amp... this is what you get
they obviously had a firmware update but its questionable if they can be bothered to make it user accessible
undoubtedly some of the guys out there will stuff up the update and end up as returns
so they're not going to fix hum and display issues when they arent show stoppers
further how much longer are they selling this? there's probably an A400 coming soon
you bought a $200 china made amp... this is what you get
they obviously had a firmware update but its questionable if they can be bothered to make it user accessible
undoubtedly some of the guys out there will stuff up the update and end up as returns
so they're not going to fix hum and display issues when they arent show stoppers
further how much longer are they selling this? there's probably an A400 coming soon
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They might ignore you but if they want to stop returns they're going to need to fix it, I would think.Display glitches were reported early on by me. Please refer to the page below.
I reported this matter to SMSL, but unfortunately it was ignored.
New SMSL A300 BTL Class-d Power Amp
Apart from extra power, any audible benefits that you immediately noticed? Slightly more dynamic tons of headroom to drive any speaker. Even at low volumes of 55-60 db it sounded great. I tried it with speakers ranging from 85 db - 92 db and I’m amazed by how well it drives them all. The A300...
I'm interested in Wharfedales 12.1, which dac/amp would you recommend for these speakers, one of those you mentioned or perhaps a similarly priced one, if there's one? I'm leaning towards a neutral or alternatively a slightly warmer sound.
there's a heap of reviews:
www.audiosciencereview.com
88dB 5" driver... i mean just about anything, even one of those 15-20w wonders like the $99 smsl or the loxjie would drive these to quite high spl
they seem to be well regarded so really... if you want to smsl it... the a300 with something like an su6 or c100 would kill it
except for the fact the speaker does not have a lot of bass given 5" drivers wont go down low, so you might want a sub but its up to your tastes
also the 300 has sub out but its not the clear cut subwoofer companion depending on how you want to hook things up
Wharfedale Diamond 12.1 Review (Speaker)
This is a review and detailed measurements of the Wharfedale Diamond 12.1 bookshelf speaker. It was kindly purchased by a member and drop shipped to me. It costs US $399 for a pair. The look and feel of the 12.1 is definitely above the budget category: The back is rather pedestrian but...
www.audiosciencereview.com
88dB 5" driver... i mean just about anything, even one of those 15-20w wonders like the $99 smsl or the loxjie would drive these to quite high spl
they seem to be well regarded so really... if you want to smsl it... the a300 with something like an su6 or c100 would kill it
except for the fact the speaker does not have a lot of bass given 5" drivers wont go down low, so you might want a sub but its up to your tastes
also the 300 has sub out but its not the clear cut subwoofer companion depending on how you want to hook things up
Thanks for your help, yeah - i'm worried about the bass, but then again, what other choice do i have in this price range? there's Q Acoustics 3030i but i couldn't find a review here. Loxjie A30 looks tempting as it also has an integrated USB DAC and thus represents the best value from what i see. My plan was to avoid purchasing a subwoofer so perhaps something that goes a bit lower and does not cost more than 12.1/12.2? Thank you.there's a heap of reviews:
Wharfedale Diamond 12.1 Review (Speaker)
This is a review and detailed measurements of the Wharfedale Diamond 12.1 bookshelf speaker. It was kindly purchased by a member and drop shipped to me. It costs US $399 for a pair. The look and feel of the 12.1 is definitely above the budget category: The back is rather pedestrian but...
88dB 5" driver... i mean just about anything, even one of those 15-20w wonders like the $99 smsl or the loxjie would drive these to quite high spl
they seem to be well regarded so really... if you want to smsl it... the a300 with something like an su6 or c100 would kill it
except for the fact the speaker does not have a lot of bass given 5" drivers wont go down low, so you might want a sub but its up to your tastes
also the 300 has sub out but its not the clear cut subwoofer companion depending on how you want to hook things up
Beyond the 6 (? 7) EQ settings, im also curious about the hipass setting cutoff 50 hz, and quite what that does and doesn’t do to the main and sw outputs.
the Q Acoustics 3030i is a very well regarded speaker... because its a UK EU thing its not surprising Amir hasnt review it... that's just the nature of a US based website
i would buy these ones without much hesitation given they are so well liked... and they are 6.5" which is better
One of the best seats of speakers I own is a Canton GLE which also has 6.5" which I find to be the lowest that I would go without a sub... I'm not a huge fan of 2.1 systems... I mean I literally have an 8" 10" and 12" sub in this same room and only one is hooked up to a HT system...
right now I'm on a set of 7.5" standmounts simply because a larger woofer suits my tastes... but the cabinets are huge
i personally would not buy a Loxjie A30 given the way it was reviewed here..
i would buy these ones without much hesitation given they are so well liked... and they are 6.5" which is better
One of the best seats of speakers I own is a Canton GLE which also has 6.5" which I find to be the lowest that I would go without a sub... I'm not a huge fan of 2.1 systems... I mean I literally have an 8" 10" and 12" sub in this same room and only one is hooked up to a HT system...
right now I'm on a set of 7.5" standmounts simply because a larger woofer suits my tastes... but the cabinets are huge
i personally would not buy a Loxjie A30 given the way it was reviewed here..
I think the descriptives in the manual for E0 to E7 correspond to the same curves used in other SMSL products, except the A300 does not use all of them. I tried to make a more readable graphic, below.
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