Impressions: SMSL PA200 GAN FET Class-D Power Amp

[Deleted member 72219]

I got (back) into hi-fi listening a couple of years ago, after quite a long hiatus, and started playing catch-up, and one of the hardest games of catch-up was my power amp game. Long story short I started with Fosi ZA3s, then V3 Monos, then Topping B100s, and finally auditioned a Hypex nCore-based amp, and there was just something lacking with each of them. The V3 Monos had plenty of power, but the sound wasn’t as good as the amazing B100s. The B100s unfortunately just didn’t make enough power to really make my LS50 Metas sing, even when high-pass filtered and supplemented by my mighty SVS SB-3000 subwoofer handling the bottom-end. The B100s cut-out in my numerous times because of safety mechanisms. I loved their sound (could be that they’re class-B as opposed to class-D? Or could just be their insane measurements), but the power limits weren’t practical. I had been researching higher-end class-D amps so I tried an IOM Ultra (NC252MP) which sounded good and was plenty powerful, but still not as good sounding as the B100s. Plus the power-on/-off pop was annoying me, so I gave that amp to my dad, who happily replaced the pair of V3 Monos I had given him with it. Finally I read that people say GAN FET class-D amps wouldn’t be truly beneficial until they took advantage of the technology and came out with a design that utilized a much higher switching frequency (say, 1MHz) than MOSFET designs (400-600KHz).

Then came along SMSL’s new PA200 power amp. Based on Infineon’s latest GAN FET technology, these amps truly use a 1MHz switching rate. They have an integrated, bypassable Texas Instruments chip-based volume control if you run the amp stereo via single-ended input. The amp also allows bridging via balanced, differential input (which bypasses the volume control by default). Power figures are astonishing, but moreover, the rated THD+N approach the numbers of the vaunted Topping B100 and B200 amps. Could these finally be the holy grail of amps with class-D efficiency and power but class-A/B sound signature combined with near-SOTA measurements? I decided it was time to find out, so I ordered up a pair.

Got them for about $700 shipped for the pair after combining store coupon from SMSL’s AliExpress store plus various seasonal AliExpress app coupons. The came in, I hooked them up, and listened…and hallelujah!!! These sound as good as the B100s at low to mid volumes, but with absolutely vast power on tap. I had heard that LS50 Metas need big power to truly sing, but I never really believed or understood that until now. They really blew the B100s away at high volumes. I literally didn’t even know my speakers could sound so good. Blew away the NC252MP. Blew away the V3 Monos. Blew away the B100s. I haven’t heard B200s, but in my mind they may be the only thing that comes close in this price range, but actually they cost almost 50% more MSRP.

Negatives? Just a couple:
1) no 12V trigger. Really miss that from the ZA3s and NC252MP, but then again on the NC252MP it was annoying due to the pops when powering on or off, and there was no trigger bypass on the NC252MP see edit below
2) only comes in silver, and the rest of my gear is black—first world problems
3) no signal-sense auto-on/-off but see edit below
4) also a faint pop when powering on, so I am just leaving them on, since the GAN FETs are efficient enough when idle

Summary: SMSL PA200 sounds amazing, has ridiculous power, especially in bridged mono mode, and build quality is excellent. You just need to get over the lack of black color way and lack of power-on/-off automation.

EDIT: Somebody pointed me to this product, which resolves the lack of 12V trigger, because I tested the power-on behavior of the amps when power is cut and restored while the amp is on, and it powers back up on its own once power is restored:

Amazon.com

-Ed

 

[Absoluterock]

Is it really fair to compare a pair of amps that are $800 to the v3 monos that are 1/4 the price?

Wonder if the juice is worth the squeeze for a smaller listening room…

Thanks for the review. They do look awesome.

 

[Deleted member 72219]

Is it really fair to compare a pair of amps that are $800 to the v3 monos that are 1/4 the price?

Wonder if the juice is worth the squeeze for a smaller listening room…

Thanks for the review. They do look awesome.

You’re right—probably a fairer comparison against the B100s; well worth the difference. And anything Hypex or Purifi for a truly fair fight.

-Ed

 

[MaxBuck]

It's very pretty, and I'm sure it's quite competent. Glad you're enjoying your purchase.

 

[Danieru Senpai]

Awesome detailed write up, seems like this amp might be well worth the wait.

I’m curious about two things:

1-Do you have any impressions on the limitations/cons of a single PA200 running both LS50s in stereo mode?

2-How has it behaved heat-wise? It seems to have an internal power supply and the 400w rating for such a small, apparently non-vented enclosure is a bit concerning. Just wondering if it’s prone to triggering protection mode on highly dynamic songs or after hours of continuous use.

 

[BeeKay]

Thanks for sharing. Asking as a fellow cat owner - cable protection?

 

[Audionaut]

I literally didn’t even know my speakers could sound so good. Blew away the NC252MP. Blew away the V3 Monos.

Hello Ed,
First of all, congratulations on your new acquisition. You are making a huge effort to achieve good sound and have a high throughput of modern and small amplifiers.
However, you also write about your sound impressions and that the SMSL are your sonic favorites, which naturally leads to the question: What exactly sounds better?
Since these are very subjective impressions and you don't want to share any more subjective impressions on ASR, you are welcome to write me a private message if you have the time.
I'm really interested.

 

[boxerfan88]

Thanks for sharing. Nice to see/read some enduser subjective impressions.

I wonder what may cause these differences? Amplifier-speaker load interaction?

 

[MCH]

Have you measured the power consumption at idle - not standby -. The website says power consumption 40 W at "normal volume", that could mean anything, but still, seems way too high.

 

[Bleib]

So, these are entirely quiet if you place your ear close to the treble?

 

[Deleted member 72219]

Awesome detailed write up, seems like this amp might be well worth the wait.

I’m curious about two things:

1-Do you have any impressions on the limitations/cons of a single PA200 running both LS50s in stereo mode?

2-How has it behaved heat-wise? It seems to have an internal power supply and the 400w rating for such a small, apparently non-vented enclosure is a bit concerning. Just wondering if it’s prone to triggering protection mode on highly dynamic songs or after hours of continuous use.

1) I think if you’re high-pass filtering the LS50 Metas and running a subwoofer for bass, a single PA200 is more than fine for a normal sized room. I wanted the extra oomph as my room is bigger and sometimes I crank it for parties with the back yard slider doors open. Running full range is probably even okay, but maybe not crazy loud.

2) no, have not seen heat being an issue at all, even after hours at higher volume. The GAN FETs are just incredibly efficient. Running two of them bridged mono helps too on an individual unit level.

Thanks for sharing. Asking as a fellow cat owner - cable protection?

View attachment 432616

Yes, I have a cat that loves to chew on wires. This is also why I have all that crap in the lowest shelf of the rack, at the sides of the rack, and behind the subwoofer—to keep him from getting behind the rack and chewing on the wires back there. Fortunately he never goes at it from the top!

Thanks for sharing. Nice to see/read some enduser subjective impressions.

I wonder what may cause these differences? Amplifier-speaker load interaction?

From a technical standpoint, if I had to guess, the ultra-high switching speed of the GAN FETs, which makes the class-D amps effectively more like pure analog amps (class-A), because of the significantly reduced dead time. This is purely conjecture, of course, but explains to me why these sounded more like the B100s to me than anything else.

Have you measured the power consumption at idle - not standby -. The website says power consumption 40 W at "normal volume", that could mean anything, but still, seems way too high.

Unfortunately I do not have any tools left to do this. I gave away my pair of Power Angels years ago to someone who would use them regularly.

So, these are entirely quiet if you place your ear close to the treble?

I have to have my ear within 6” of the tweeter to hear any noise floor sound, which is an extremely faint, high-frequency sort of hiss.

-Ed

 

[Sokel]

View attachment 432485

View attachment 432486

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View attachment 432488

I got (back) into hi-fi listening a couple of years ago, after quite a long hiatus, and started playing catch-up, and one of the hardest games of catch-up was my power amp game. Long story short I started with Fosi ZA3s, then V3 Monos, then Topping B100s, and finally auditioned a Hypex nCore-based amp, and there was just something lacking with each of them. The V3 Monos had plenty of power, but the sound wasn’t as good as the amazing B100s. The B100s unfortunately just didn’t make enough power to really make my LS50 Metas sing, even when high-pass filtered and supplemented by my mighty SVS SB-3000 subwoofer handling the bottom-end. The B100s cut-out in my numerous times because of safety mechanisms. I loved their sound (could be that they’re class-B as opposed to class-D? Or could just be their insane measurements), but the power limits weren’t practical. I had been researching higher-end class-D amps so I tried an IOM Ultra (NC252MP) which sounded good and was plenty powerful, but still not as good sounding as the B100s. Plus the power-on/-off pop was annoying me, so I gave that amp to my dad, who happily replaced the pair of V3 Monos I had given him with it. Finally I read that people say GAN FET class-D amps wouldn’t be truly beneficial until they took advantage of the technology and came out with a design that utilized a much higher switching frequency (say, 1MHz) than MOSFET designs (400-600KHz).

Then came along SMSL’s new PA200 power amp. Based on Infineon’s latest GAN FET technology, these amps truly use a 1MHz switching rate. They have an integrated, bypassable Texas Instruments chip-based volume control if you run the amp stereo via single-ended input. The amp also allows bridging via balanced, differential input (which bypasses the volume control by default). Power figures are astonishing, but moreover, the rated THD+N approach the numbers of the vaunted Topping B100 and B200 amps. Could these finally be the holy grail of amps with class-D efficiency and power but class-A/B sound signature combined with near-SOTA measurements? I decided it was time to find out, so I ordered up a pair.

Got them for about $700 shipped for the pair after combining store coupon from SMSL’s AliExpress store plus various seasonal AliExpress app coupons. The came in, I hooked them up, and listened…and hallelujah!!! These sound as good as the B100s at low to mid volumes, but with absolutely vast power on tap. I had heard that LS50 Metas need big power to truly sing, but I never really believed or understood that until now. They really blew the B100s away at high volumes. I literally didn’t even know my speakers could sound so good. Blew away the NC252MP. Blew away the V3 Monos. Blew away the B100s. I haven’t heard B200s, but in my mind they may be the only thing that comes close in this price range, but actually they cost almost 50% more MSRP.

Negatives? Just a couple:
1) no 12V trigger. Really miss that from the ZA3s and NC252MP, but then again on the NC252MP it was annoying due to the pops when powering on or off, and there was no trigger bypass on the NC252MP
2) only comes in silver, and the rest of my gear is black—first world problems
3) no signal-sense auto-on/-off
4) also a faint pop when powering on, so I am just leaving them on, since the GAN FETs are efficient enough when idle

Summary: SMSL PA200 sounds amazing, has ridiculous power, especially in bridged mono mode, and build quality is excellent. You just need to get over the lack of black color way and lack of power-on/-off automation.

-Ed

Glad you like it but not comparable to rest with its 90dB SINAD .
That may explain the noise you hear too.

In short, there's no clue than GAN can have audible benefits.
What it can do is to be more efficient and can be used at high power (we're talking high, kW here) .
At its rated power with that enclosure I wouldn't be confident driving them hard.

(I told you before, get a Purifi and be done with it)

 

[Deleted member 72219]

Have you measured the power consumption at idle - not standby -. The website says power consumption 40 W at "normal volume", that could mean anything, but still, seems way too high.

As a follow up, I left the amps on overnight with nothing playing. This morning I checked with my hand and the amp casing is indeed warm to the touch (not crazy hot, but warm).

-Ed

 

[Deleted member 72219]

Glad you like it but not comparable to rest with its 90dB SINAD .
That may explain the noise you hear too.

In short, there's no clue than GAN can have audible benefits.
What it can do is to be more efficient and can be used at high power (we're talking high, kW here) .
At its rated power with that enclosure I wouldn't be confident driving them hard.

(I told you before, get a Purifi and be done with it)

While you say that, there is something that this amp gives me that no other does—I’m done looking at amps now that I have these. If the Purifi don’t really sound any different than the NC252MP, then I’d be continuing to waste my time and money. That is no longer the case now that I have this pair of PA200.

That alone is worth it.

-Ed

 

[Bleib]

I have to have my ear within 6” of the tweeter to hear any noise floor sound, which is an extremely faint, high-frequency sort of hiss.

Thanks, I guess not quite state of the art then yet. Not that I need more for my current speakers in terms of power anyway, Denon and TP amps are good enough for me too.
Comparing TP RA3 with Fosi V3 mono didn't give more performance, sounded exactly the same

 

[totti1965]

While you say that, there is something that this amp gives me that no other does—I’m done looking at amps now that I have these. If the Purifi don’t really sound any different than the NC252MP, then I’d be continuing to waste my time and money. That is no longer the case now that I have this pair of PA200.

That alone is worth it.

-Ed

Ja! I hope, these little gems will stay some years in your setup! By the way: Beautiful pictures that you made!
As a just 90 % scientific and 10 % subjectivist listener, I simply think there is something about the GAN technology and the (ultra-) high switching modes, even though Bruno Putzeyes claim, that GAN only makes sense in Power Ranges of more than 1000 Watts.... (I have read everything I could find written by him - a real Class D Guru! - for the theoretical background)
https://linearaudio.net/sites/linearaudio.net/files/volume1bp.pdf;

Life on the Edge - A Personal Perspective on the Past, Present, and Future of Class D Audio Amplifiers - HomeTheaterHifi.com

The past quarter century of class D developments look strikingly different when seen through the eyes of the audio consumer and through...

hometheaterhifi.com

 

[Lars Risbo]

so what do you think that ‘something ‘ is?

 

[Deleted member 72219]

so what do you think that ‘something ‘ is?

My best guess, as I said, is that the ultra-high switching frequency of the GAN FETs simply pushes the operation of the amp closer to, "true analog," as opposed to PWM, thanks to the much shorter dead time. The only explanation as to why I found they sounded more like the Topping B100s (actual class-B amps) than any of the class-D amps.

Of course, this is pure conjecture. I may be completely wrong.

-Ed

 

[totti1965]

so what do you think that ‘something ‘ is?

I don't really dare to say it in this forum, but "airiness" - especially when listening to analog or high-res sources.
Not necessarily GAN Tech, but amps with extremely high bandwidth, like the B100 / B200.

 

[sucramhabib]

View attachment 432485

View attachment 432486

View attachment 432487

View attachment 432488

I got (back) into hi-fi listening a couple of years ago, after quite a long hiatus, and started playing catch-up, and one of the hardest games of catch-up was my power amp game. Long story short I started with Fosi ZA3s, then V3 Monos, then Topping B100s, and finally auditioned a Hypex nCore-based amp, and there was just something lacking with each of them. The V3 Monos had plenty of power, but the sound wasn’t as good as the amazing B100s. The B100s unfortunately just didn’t make enough power to really make my LS50 Metas sing, even when high-pass filtered and supplemented by my mighty SVS SB-3000 subwoofer handling the bottom-end. The B100s cut-out in my numerous times because of safety mechanisms. I loved their sound (could be that they’re class-B as opposed to class-D? Or could just be their insane measurements), but the power limits weren’t practical. I had been researching higher-end class-D amps so I tried an IOM Ultra (NC252MP) which sounded good and was plenty powerful, but still not as good sounding as the B100s. Plus the power-on/-off pop was annoying me, so I gave that amp to my dad, who happily replaced the pair of V3 Monos I had given him with it. Finally I read that people say GAN FET class-D amps wouldn’t be truly beneficial until they took advantage of the technology and came out with a design that utilized a much higher switching frequency (say, 1MHz) than MOSFET designs (400-600KHz).

Then came along SMSL’s new PA200 power amp. Based on Infineon’s latest GAN FET technology, these amps truly use a 1MHz switching rate. They have an integrated, bypassable Texas Instruments chip-based volume control if you run the amp stereo via single-ended input. The amp also allows bridging via balanced, differential input (which bypasses the volume control by default). Power figures are astonishing, but moreover, the rated THD+N approach the numbers of the vaunted Topping B100 and B200 amps. Could these finally be the holy grail of amps with class-D efficiency and power but class-A/B sound signature combined with near-SOTA measurements? I decided it was time to find out, so I ordered up a pair.

Got them for about $700 shipped for the pair after combining store coupon from SMSL’s AliExpress store plus various seasonal AliExpress app coupons. The came in, I hooked them up, and listened…and hallelujah!!! These sound as good as the B100s at low to mid volumes, but with absolutely vast power on tap. I had heard that LS50 Metas need big power to truly sing, but I never really believed or understood that until now. They really blew the B100s away at high volumes. I literally didn’t even know my speakers could sound so good. Blew away the NC252MP. Blew away the V3 Monos. Blew away the B100s. I haven’t heard B200s, but in my mind they may be the only thing that comes close in this price range, but actually they cost almost 50% more MSRP.

Negatives? Just a couple:
1) no 12V trigger. Really miss that from the ZA3s and NC252MP, but then again on the NC252MP it was annoying due to the pops when powering on or off, and there was no trigger bypass on the NC252MP
2) only comes in silver, and the rest of my gear is black—first world problems
3) no signal-sense auto-on/-off
4) also a faint pop when powering on, so I am just leaving them on, since the GAN FETs are efficient enough when idle

Summary: SMSL PA200 sounds amazing, has ridiculous power, especially in bridged mono mode, and build quality is excellent. You just need to get over the lack of black color way and lack of power-on/-off automation.

-Ed

Nice looking amps! Thinking of trying one myself