Impressions: SMSL PA200 GAN FET Power Amps

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