SMSL PA-X Stereo Amplifier Review

[Foxxy]

GaN, or gallium nitride-based semiconductors, are neither a miracle technology nor anything new. It is simply the next stage of development after silicon-based semiconductors, with improved energy efficiency at high switching frequencies, especially at high power levels. GaN cannot be used effectively in conventional analog amplifiers.

And so far, it offers no advantage in audio amplifiers, except in switching power supplies.
Current GaN amplifiers are easily outperformed by non-GaN-based amplifiers, and they are also in a similar price range.

There is no reason to expect significant energy savings when using GaN in the power amplifiers, as the average power in real music is much lower, and the theoretically improved energy efficiency at this point will be well below 10%. Therefore, the effective energy savings achieved by GaN in power amplifiers will be in the single-digit watt range.

In addition, Infineon amplifier technology has had limitations for several generations, especially in terms of load dependence, especially at 4 ohms. GaN does not change this.

Yeah, modern MOSFETs are just great.

Here is a small blog post from IcePower showing their own findings with GaN:
IcePower Blog Post "Is GaN worth it?"
TLDR: depends, you high is your idle power draw bill from your amps? And how long until the lower idle draw offsets the higher amp cost? For most home users, classic MOSFET based is just fine.

 

[burkm]

The only GaN modules that hold up are the Orchard Audio ones

Measurements so you can compare

Starkrimson® Ultra Specs - Orchard Audio

Specifications and test results for our award-wining, state-of-the-art, Starkrimson Ultra 500W GaN audio power amplifers.

orchardaudio.com

This Orchard Audio GaN amp costs You almost 4.450USD delivered to Your home.
That is almost 20 times the amount You would pay for a set of Fosi Audio V3 Mono amps.
I don't think, they are in the same boat, but one may be challenged by the comparison...

 

[Roland68]

Something doesn't quite add up. The A-S501 has, per the usually conservative Yamaha specifications, the same maximum power as the A30a -if we go by the VMV-A2 measurements on ASR, which is also maximum power, -so there's no real indication that the Yamaha wouldn't be able to "keep up" with the A30a..
Could be classic expectations playing tricks?

You're simply making false assumptions, but I'll answer that later in the A30a thread.
As @JSmith already pointed out, this is the wrong thread for this.

 

[DrCWO]

Hi @amirm,
Why can't we vote for this AMP??

 

[Geert]

Hi @amirm,
Why can't we vote for this AMP??

Yes. I figured since it broke, it wouldn't be fair to subject it to polling. I could add it though.

 

[Roland68]

This Orchard Audio GaN amp costs You almost 4.450USD delivered to Your home.
That is almost 20 times the amount You would pay for a set of Fosi Audio V3 Mono amps.
I don't think, they are in the same boat, but one may be challenged by the comparison...

Aside from being so expensive, it's based on the same limited Infineon technology.
I'd like to see neutral measurements to see if there's actually been a significant improvement, but even then, there would be cheaper alternatives that are just as good or even better.

 

[Tovarich007]

Thanks for this review Amir.
Rather disppointing results for this amp. performances are mostly average. Worse SNR on XLR vs. unbalanced RCA is kind of an anomaly. GaN semiconductors bring nothing better than silicon chips, the proof is here. The FR is very short in the extreme trebel and not straight flat in this range (I'm and not sure I could hear a diffrence but anyway, a lot of class D re doing better in this criteria, not to mention the class AB).
Cute, but not worth the price IMO.

 

[Kevinfc]

Seems like a perfectly adequate, though not exceptional offering.

 

[PristineSound]

Hi @amirm,
Why can't we vote for this AMP??

This question was asked, the answer is because the review is considered incomplete due to the unit breaking down as a result of a FTC-like test that likely over stressed the unit.

 

[375HP2482]

Do we know if this was an amplifier failure, or a power supply failure?

 

[doc2c]

Ugh! what are you doing Smsl? You're better than this

 

[PristineSound]

In fact it was no “FTC-like” test, it was an easy test for a properly designed amplifier to pass. It only shows how poorly designed are those xi-fi amplifiers and how big hype is created around them here at ASR. Sad, more sad is the ignorance.

I agree with the questionable reliability and robustness of this amp as I have stated as well earlier.

I also can say based on my personal experience, I did not have much luck in terms of reliability and bugs/design flaws with SMSL and to a much lesser extend Topping as well.

 

[daniboun]

This Orchard Audio GaN amp costs You almost 4.450USD delivered to Your home.
That is almost 20 times the amount You would pay for a set of Fosi Audio V3 Mono amps.
I don't think, they are in the same boat, but one may be challenged by the comparison...

Right.
Orchard Audio is completely off the wall regarding their pricing.

---

 

[martin900]

Why oh why they still use the PGA2311...have yet to hear a good sounding implementation. SOTA GaN output stage and old single chip volume control...bummer.

Lack of option to vote questions the credibility of the review in general in my opinion.

Condidering it broke already during testing, it should be considered a 'headless panther'. A well designed product should contain all the safeguards needed like OTP and OCP.

 

[amirm]

Do we know if this was an amplifier failure, or a power supply failure?

I will open it later and see what I can figure out.

 

[Ajax]

I know there is the typical consensus 200 watts is enough for a standard bookshelf speaker, however my Troel Scanspeak 3WC clips under a NC252MP even without DSP.

I would expect the best way forward to close the deal with future amplifiers sales is a clean 300 watts at 8ohm at under $600.

This barely competes with the Hypex amps, no protection and essentially no differentiation.

Any way of trialing your speakers with the next step up being a Buckeye NC502 ($725), to see if your problem persists. Massive amounts of power with slighlty better performance than the NC252. Amir reviewed an 8 channel version.

Buckeye NC502MP 8-Channel Amp Review

This is a review and detailed measurements of the Buckeye Hypex NC502MP 8-channel class D amplifier. It was sent to me by the company and costs US $2,295. There is not a whole lot to look at here. Sheet metal is rather thin and fitment not that great. So put it in a cabinet and forget about...

www.audiosciencereview.com

"The Buckeye NC502MP is a perfect amplifier for home theater duty. It provides incredible amount of power from each module to drive even the most inefficient speakers to ear piercing levels. It does so with extremely low noise and excellent distortion at modest levels. At higher powers, distortion does climb. While I wish this was lower, I don't think there is an issue at all for home theater applications. Even with music, I think you will be fine but the purist may want to have better. Then again, if you are going to lose power to get there, this amplifier may be a better choice."

Buckeye Amps

Buckeye Amps utilizes the most advanced audio amplifier technologies available. Authorized seller for Hypex and Purifi Class D amplifiers. Based in the US. Free shipping and worldwide service!

www.buckeyeamp.com

 

[amirm]

Lack of option to vote questions the credibility of the review in general in my opinion.

Say what? No other reviewer has a poll. That I have it, is something extra. It is pretty bad form to damn the review because I didn't provide a poll. If that is all that it takes to lose "credibility" in your eye, then I suggest going and reading other people's reviews.

 

[PristineSound]

Say what? No other reviewer has a poll. That I have it, is something extra. It is pretty bad form to damn the review because I didn't provide a poll. If that is all that it takes to lose "credibility" in your eye, then I suggest going and reading other people's reviews.

Why oh why they still use the PGA2311...have yet to hear a good sounding implementation. SOTA GaN output stage and old single chip volume control...bummer.

Lack of option to vote questions the credibility of the review in general in my opinion.

Condidering it broke already during testing, it should be considered a 'headless panther'. A well designed product should contain all the safeguards needed like OTP and OCP.

How would a poll add to the credibility of the review?

It's not like the people voting on the poll did a bench test on the unit.

The overwhelming vast majority of the people voting in the poll doesn't even have the unit.

I view the poll as something fun for forum members.

 

[TimF]

the remote seems designed for my level of expertise.

 

[Lambda]

@amirm waht is the reason for the volume "gain" setting of 66/70?
to get ~24dB gain?
to get max power at 4Vrms?