SMSL PA-X Stereo Amplifier Review

[classaistheway]

I agree. Amps are for listening to music not test tones. It's a shame it failed rather than shutting down but there's a disproportionate amount of ridicule being placed on an amp that probably won't fail under any normal use conditions.

 

[Old_School_Brad]

I agree. Amps are for listening to music not test tones. It's a shame it failed rather than shutting down but there's a disproportionate amount of ridicule being placed on an amp that probably won't fail under any normal use conditions.

And how exactly do you know that?

This amplifier’s performance is being evaluated in the context of every other unit Amir has tested -and will test -the vast majority of which handle this relatively undemanding test without shutting down. Keep in mind, this isn't even close to being as rigorous as the standard FTC testing, yet the unit still failed. The way it did points directly to a design flaw in the protection circuitry, which is the manufacturer’s responsibility.

Unrelated, but here are the obligatory poor analogies -use at your own risk:
Imagine a car manufacturer complaining about NCAP crash tests by saying, “Cars are made to be driven, not crashed.”
Or picture the hypothetical situation where a major tech company dismissing reception issues by saying, “You’re holding it wrong.”

Both sounds a bit silly, right?

 

[kyuu]

The way it did points directly to a design flaw in the protection circuitry, which is the manufacturer’s responsibility.

Yep. It's not a problem, IMO, that it went into protection during the test. The fact that it could not recover and basically became a brick is a big problem, though. It's not as though the conditions to trigger a protection circuit are unthinkable, that's why protection circuits exist.

 

[classaistheway]

Unrelated, but here are the obligatory poor analogies -use at your own risk:
Imagine a car manufacturer complaining about NCAP crash tests by saying, “Cars are made to be driven, not crashed.”
Or picture the hypothetical situation where a major tech company dismissing reception issues by saying, “You’re holding it wrong.”

Both sounds a bit silly, right?to

To take your analogy further, do you expect to live if you're stupid enough to drive into a wall at 200mph just because your car passed safety testing? That's the auto equivalent of letting an amp clip for extended periods with RMS power levels way beyond the point where it would start sounding bad.

Audio is not a sinewave and you will hear clipping on large swings long before RMS power gets to the level seen in this test.

I agree, the amp should not have failed permanently during this test but I maintain it's likely not an indication of how it will perform under real world conditions with a half observant operator.

 

[Old_School_Brad]

Audio is not a sinewave and you will hear clipping on large swings long before RMS power gets to the level seen in this test.

I agree, the amp should not have failed permanently during this test but I maintain it's likely not an indication of how it will perform under real world conditions with a half observant operator.

This is one of those debates that will likely never be settled.

You see the “FTC-like” test as too demanding -I see it as laughably easy. In my view, any properly designed amplifier should pass it without breaking a sweat. I continue to support the principles behind the FTC power tests and even believe the required duration should be extended.

That said, I do respect differing opinions on the matter.

But here’s the bottom line: Amir’s testing is consistent, which makes it useful for comparing amplifiers under identical conditions. And under those same conditions, this particular amplifier didn't fare well, while the vast majority of others handled the test just fine.

Given that, I think it's entirely fair to direct some criticism at the design.

 

[classaistheway]

I think you may not have been interpreting my message the way I intended. I agree with you about the test and I agree the amp should have failed it in a more graceful manner. A simple linear power supply with an accessible and appropriately rated fuse fails more gracefully than this did. Of course, I would like to see all modern amps pass the test.

All I was saying was that I don't think this test necessarily shows that the amp will be unreliable or problematic in every day use for playing music.

 

[Roland68]

For this kind of money, performance like this has pretty much never existed — but if there's a 1.5 dB drop at 20 kHz, then you think it's terrible The amp sounds fucking great, it's a best buy, and you just pass it by — congrats.

But you have to have a lot of blinders on for that. Personally, I find the price very high considering the power and measurements, especially for a manufacturer like SMSL, whose warranty is only available through specialist retailers and has no repair options.

Just a small selection of alternative amplifiers.

The NAD 2200 was better over 35 years ago and has significantly more power. Even at 8 ohms, more comes out than at 4 ohms with the PA-X. For that price, you can get two used NAD 2200s.

The Sabaj A30a has the same power, but better measurements, no load dependency, and is cheaper.

The 3E Audio A7 also has the same power, slightly higher max power, significantly better measurements, and is significantly cheaper.

AUDIOPHONICS AP300-S250NC €549, higher power, better measurements.

AUDIOPHONICS AP300-S500NC approx. same price, more than double the power at 4 ohms, almost 3 times the power at max power, better measurements.

 

[xanalog]

Well, it measured worse than amps 1/3rd the cost and died. Excuse me if I’m not lining up for it…

 

[Megadeaf]

I am happy with my dual A300 setup bit I got hyped for dual Pa x. Has anyone tested these in mono operation?