Topping L50 Headamp Review and Measurements: Another One Bites The Dust

I don't plan on commenting much on the L50 as I know there is probably no interest in this from readers of this site. However, I did wanted to post some measurements. This unit was not sent or gifted to me by Topping. I had to buy it from Amazon (there are some discounts going on with Topping gear which I am never seen before. Act now!). Let's just start with ASR type measurements.



Topping L50
2Vrms into 300-ohm resistor load
Unity gain (low gain)
SE output


SINAD for above with 20kHz bandwidth.


Yup exactly what we expected! The results for this measurement are nothing short of spectacular! This is singled-ended too. I think I must have gotten a Ti or Super edition of this because these numbers pip ASR's numbers by 1db.

ABX Blind Test Impressions Comparing Against Magni Unity: https://www.superbestaudiofriends.o...magni-unity-vs-topping-l50.13971/#post-419979

Let's checkout measurements into planar type loads next...

 

So let's try a 26.4-ohm load. I'll to settle on a standard low-impedance load eventually. 32-ohms seems too high today given some planar designs as running as low as 8-ohms and HFMs and Audezes under 20-ohms.

Topping L50
2Vrms into 26.4-ohm load (300 || 300 || 32)
Unity gain (low gain)
SE output






Whoa! What's going on here! Do I get defective gear again? WHY I DO ALWAYS GET DEFECTIVE CHI-FI (ENTRY LEVEL) GEAR! This is the second time in a matter of days that I received something defective from a cheap Chi-Fi gear manufacturer. I'm like 2 for 7 with respect to getting something that passed QC. Examples below. This just cannot be a statistical fluke. C'mon guys, stop using jailed dissidents on the organ harvest list for workers.

• https://www.superbestaudiofriends.org/index.php?threads/douk-audio-u3-review-the-douk-of-wishful-thinking.13953/
• https://www.superbestaudiofriends.o...headphone-amp-measurements.12427/#post-385954
• https://www.superbestaudiofriends.o...iew-and-measurements.11164/page-2#post-352240
• https://www.superbestaudiofriends.o...ping-l30-review-and-measurements.11164/page-5
  
• https://www.superbestaudiofriends.o...ncoz-sgd1-vs-geshelli-jnog.10955/#post-347162

(Nothing against Chi-Fi or China. The higher-end Chinese brands remain as excellent as ever. FWIW, I am ethnically Chinese and try to impart on my kids Eastern values -vs- today's Western consumerist values).

It looks like one channel is broken! Ok, to be fair, let's use SBAF standards. 2Vrms is way too high. Let's try 0.775Vrms or 0dBu. Now this is a little bit better. Still, we can see that there is something very wong on one channel.



Ch2 measurements removed only showing Ch1.

 

Chip amps can do absolutely fine with low-Z headphones provided they are designed properly. The L50 here could be a case of counterfeit parts, wrong parts, bad solder, etc. It happens. One channel (blue) appears to be working properly. I have no doubt this is a defective unit. I just don't understand why I keep getting defective units (again, reminding readers that SBAF tends to buy stuff through regular channels).

If there is any discourse, it will likely be one of conspiracies related to the frequency of which I obtain defective entry-level Chi-Fi audio gear.

Topping is welcome to chime in or suggest what I could be doing wrong. I’ve done this for Grace and other manufacturers in the past where measurements didn't pan out. I will do it for any manufacturer. I am also willing to send this unit back to Topping (at their expense - they can send me a DHL return slip) for them to analyze. If there is something wrong, they can send me a non defective unit and I will remeasure and reassess. It's about being fair, knowing that I am human, and that I can mess up.

 

Here is something that is interesting, the L30 I tested a while back also had something very similar wrong with it when it came to low Z loads. And this only 32-ohms.

Topping L30
THD+N vs power
32 ohm load, 1kHz, 90kHz bandwidth

 

Quick reality check. Want to make sure not me or my equipment. It's always possible. Here's Heretic into 26.40-ohms

Schiit Heretic
0dbFS 1kHz into 26.4-ohms

 

IMO an 8-ohm is unreasonable because only Moondrop is stupid enough to do that. And even then, it's possible the Moondrop could be voltage sensitive enough where we would need to reassess appropriate voltage levels to test. This is about being a good scientist*. The last thing we want to do is arbitrarily select a number that has nothing to do with realistic use. However, if we start seeing moderate sensitivity 8-ohm headphones, then making 8-ohm loads part of the test would be prudent.

*For example CFA IEMs are 2-ohms, but they are so super sensitive that they aren't going to push amps very hard.

This did get me thinking: Maybe we should just eliminate the 300-ohm test. It's too easy. If there are distortion spikes in the 32-ohm, 29-ohm, or 26.4-ohm load tests, they are pretty much not going to be there in any meaningful way with a 300-ohm load.

 

To put things into perspective, the borked channel measurements are not bad. They most certainly would not be considered bad on SBAF, especially for people who have enjoyed the SW51, tube amps, etc. So what? There's a distortion spike at -90db or -85db at the second and harmonic. No one would blink an eye here. And even then, we are talking 2Vrms output levels, which no one in real life ever reaches, unless they are running an HE6, because this output level will destroy our hearing or burn out the voice coils on most headphones. The fact is, if we were running a Sennheiser HD6**/800 headphone, we wouldn't even reach this condition, and everything would be perfect, just like the graph in the first post.

What's bad is that the left and right channels perform differently at higher output levels into lower impedance loads. I just can't see this as being consistent for a company that purports to be state-of-the-art, designing by APx555, and slapping "SINAD" results on marketing materials.

My view is that if you live by measurements, then you should die by them.

 

I think you are reading too much into it. You said it yourself, avoid random brands. It's just that the random or "entry-level" (trying to be polite) brands when it comes to consumer audio happen to be Chinese brands.

As for made in China, never said made in China sucks. It's really how much the brand cares about QC and how they may want to manipulate reality by sending cherry picked items to certain reviewers. iPhones are made well - anything messed up on iPhones is usually a result of design bugs. iFi, Holo, Auralic, Shanling are made in China - never had an issue with any of their stuff.

 

It's industrial policy and the current situation. Going back to Deng Xiaoping. The Communist party made a conscious effort to modernize through industrialization (and opening trade). After China joined the WTO around 2000, they solidified their place as the factory floor for the world. It's all about making stuff and keeping people employed - social harmony - because China at any time is seriously in legit danger of a revolution (e.g. 1989 Tiananmen Square, which the Communists took care of by massacring the student protesters of the Democracy Movement. Most of you guys are too young. I still remember Tank Man on the boob-tube. Pretty sure he "disappeared").

Brand building has never been China's strong suit until recently. There are a few strong Chinese brands today: BYD (e-cars), Huawei/OnePlus (phones), TikTok (social-media/mind-control/ subtle-propaganda). It had always been build build build, even at a loss, or with government subsidies, because growth, market share, and keeping people busy are paramount, i.e. their value system. As a result, China dumped steel, solar panels, garlic (yes, garlic), devastating these industries in the USA and other Western countries.

The handful of strong brands (mentioned above) do care about QC because that's almost the very definition of a brand. Many of the "random" brands which I have had mixed or bad experiences with have been around forever: Aune, A-GD, Douk, iBasso, Fiio, Gustard. Not sure how long SMSL, Soncoz, Topping, have been around. I seem to recall SMSL back then too. Some brands are more recognizable or stronger than others, but all are pretty weak. Topping got a big kick start with the help of Amir at ASR, who to this day I suspect consulted for them directly or indirectly. The only evidence we had were blurbs written by Amir for Shenzhen audio or a group of companies related to them on the Internet, found by @ultrabike. These have since been removed. The value system of these companies is supply side oriented: make as much crap as possible, try to sell it all, see what sticks, repeat. This is because this is the value system mandated by the Communists. Sure, China has been trying to shift things toward a consumer oriented economy, but it just ain't working.

You want to talk about a more general "value system" of the China Communists?

despotism?
hegemony over its neighbors?
misinformation (COVID)?
human rights abuses (Uyghers)?
disinformation*
cheating safety/quality (infant formula)?
forced organ harvesting?

Hate to say it, but these values, which all espouse "control", while great for manufacturing in a command economy, are an anathema for new and creative ideas. It's new and creative ideas which are crucial for real brand building.

FWIW, there's the clothing equivalent of rando audio brands today: Shein, Temu, etc. Cheap and throw away. Some of the stuff looks pretty stylish. No one will care in a few months in the world of TikTok fast fashion with kids.

Things are really bad in China right now with millions of people who bought homes, fully paid for them, but will probably never set foot in them because construction was never started or only partially completed then stopped. The situation is dire. I've never seen so much rando brand Chinese gear on discount on Amazon. For sure Topping - never saw Topping gear at the current steep discounts until recently. I know because I've tried to buy Topping gear for review going back the past few years. There's really no time for quality, new and creative ideas, or brand building. It's build as much 121db "SINAD" massive open loop gain (with corresponding massive NFB) shit as possible and sell it.

*In a WSJ article talking about how Vietnam was very sensitive to the nine-dash line, there were commenters saying that Vietnam was not actually a country until 1985! It's so obvious where that came from - a technique from Mao! China communists probably have a more active disinformation section than Russia right now (Russia is busy with other things).

P.S. The other day, and I can't find the link to the posts, someone asked what AIO they should buy. It was something along the lines of I have this because it was recommended by someone on YT or whatever, but I didn't like it, and should I buy a Fiio (or other rando Chinese brand). I responded: Look, just stop. All you are doing to moving from one rando brand to another, staying in rando brand entry level Chi-Fi purgatory. Anyway, can anyone can help me find the link to those posts?