Topping L30 xploding and taking headphones out

Discussion in 'All Points Bulletin / Be on the Look Out' started by M3NTAL, Dec 17, 2020.

  1. Cspirou

    Cspirou They call me Sparky

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    Oh look. It actually says "DC_Det" or DC Detection

    CCF8D141-076B-4A4A-939E-A043F37D44AA.jpeg

    Failure of the audio opamp is one thing. But it looks like the DC protection circuit on @M3NTAL 's board is unaffected. Which means it doesn't even work.

    And I don't see fuses anywhere on this thing.
     
    Last edited: Jan 7, 2021
  2. Baten

    Baten Friend

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    Yeah no, no fuses in here. There's only the DC protection thing, which seems severely lacking in the case of ESD.
     
  3. Cspirou

    Cspirou They call me Sparky

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    You might think that a fuse is not necessary for something that uses a wall-wart. But take a look at the Magni 2U power section which also uses a wall-wart

    SchiitMagni11-edit.jpg

    F1, which mean fuse.

    Now I don't want to totally dismiss that the L30 has no fuse because I don't have the actual unit with me. But it doesn't seem like you have fried headphones or an opamp if you did have a fuse.
     
  4. Cspirou

    Cspirou They call me Sparky

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    I have a Topping amp from 2014 pre-ASR. Although definitely not as good as my DIY gainclone, it still works perfectly fine.

    Although now I might take a closer look...
     
  5. Baten

    Baten Friend

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    May be relevant that the L30 was designed by an intern (who now works for them, JohnYang guy). I'm guessing they didn't really second guess or properly QA his design(s).. I mean what did they expect..
     
    Last edited: Jan 7, 2021
  6. Yethal

    Yethal Facebook Friend

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    I'm surprised nobody has mentioned caps held in place with a ziptie yet.
     
  7. Hrodulf

    Hrodulf Prohibited from acting as an MOT until year 2050

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    It's not that bad. If they're heavy, then you need to make sure they're not wobbling. I'd rather have zip ties than som gunk.
     
  8. bboris77

    bboris77 Friend

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    I just took a peek at the L30 thread over at ASR. As of now, no warning on the main review page about this issue - it is still "can't recommend enough". Not one word from Amir about this whole situation.

    The manufacturer's rep has come out and stated 2 things:

    1. Catastrophic failure rate (taking out the headphones) of L30 is 0.1% and regular failure is less than 1%. He does not state how they got to this figure and does not provide more info about which batches (if not all) are affected.

    2. This is a direct quote from him: "SBAF is FOS, stay away from it."

    My intent is not to start a war of words between ASR and SBAF. I am just surprised that a representative of a manufacturer would stoop as low as to insult a whole forum of audio enthusiasts in this manner. Bizarre.

    Needless to say, it will be a cold day in hell before I buy one of their products again. Their attitude to this whole incident has done more damage to their reputation than the engineering fail of the L30.
     
  9. rhythmdevils

    rhythmdevils MOT: rhythmdevils audio

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  10. YMO

    YMO Chief Fun Officer

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    Just wait until they say that SBAF is sabotaging Topping's rep. I do feel sorry for those who lose equipment due to their designs.
     
  11. Senorx12562

    Senorx12562 Case of the mondays

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    WTF is FOS? Sorry, I am old. And I would not be bragging about blowing up the headphones of 1 of every 1000 purchasers of my product. I would see that as unacceptable.
     
  12. scblock

    scblock Friend

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    Guessing Full Of Shit (Full Of Schiit?), but it's a guess.
     
  13. purr1n

    purr1n Desire for betterer is endless.

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    To be fair, I wouldn't say that they are useless. The problem right now is that we do not understand how the failure occurred. The DC detect and relays are a safeguard, but they are designed for certain kinds of foreseeable failures.

    Right now, we only have one photo of a melted opamp and no idea how or why this happened. The four others on ASR have not provided any photos, so we have no idea if the failure mode is the same. It would also appear that there is little incentive to get to the bottom of it at ASR. One owner is unwilling to pop open the case and take photos because he fears that doing so will ruin his chances of getting a refund. Amir is not willing to compensate owners for their broken amps for an analysis. He has mostly stayed silent and will continue to stay silent. Evidence of a cozy relationship between ASR and Topping / SMSL's holding company were uncovered by @ultrabike here (evidence now scrubbed): https://www.superbestaudiofriends.o...science-review-review.9827/page-8#post-316578

    I thought I had also seen a photo of a killed voice-coil, but perhaps this was in my head. I've done dumb stuff via DIYing, killed opamps, killed headphones, etc. I've blown up opamps and transistors with fire and smoke and parts flying to to the ceiling, turned capacitors into sizzling fireworks, but the melted opamp with the nuclear China Syndrome deal (char marks on the back the PCB - and pun intended) has my head scratching.

    I am curious to the opamp. Supposedly some of these latest and greatest modern opamps can be very sensitive to ESD and ESD was indicated as a possible cause at ASR. One can read through ESD precaution material on TI's site. Evidently ESD damage can be cumulative to transistors inside opamps with no external evidence of such, until boom, a latch to DC.

    So I guess John Yang is a manufacturer now instead of an "intern". Didn't he state that he was simply an intern or contractor for Topping? It doesn't matter. He should have been upfront that he was representing the interests of Topping instead of pretending to be a freelancer with plausible deniability, e.g. "happened to pick up side jobs from Topping".

    Anyway, science and statistics doesn't work like that and this statement is sidestepping the current issue at hand. Four or five people reporting on the Internets within a short time interval of catastrophic failures with headphones being taken out is very concerning. The reasons are that the vast majority of people do not participate in forums and will not report these results. Heck, even @M3NTAL's post in the middle December of last year flew by everybody's head until ASR folks' L30s started exploding recently. Finally, we don't know what the future holds, if the remaining L30s are ticking time bombs.

    We are all familiar with the story of "very low failure" rate when a handful of owners of Audeze headphone started to report dead drivers.

    This coming from a MoT who has crapped on competitors products (posts now edited or dialed back) and for a long term of time exercised plausible deniability on his relationship status with Topping / SMSL. I'm sorry, but karma is a bitch.

    It's understandable. We do have anti-Topping / SMSL bias. At least SBAF is willing to admit this bias. One would think a representative from Topping would embrace the lessons from How to Make Friends and Influence People. But it's like what I said in another thread. Chinese people, even business people, take things personally and forever to the extent that if they had an opportunity to convert enemies to friends, they would refuse. One of the strengths of Western culture is not taking things personally and the ability to turn events such as these into opportunities.

    This is a business decision. Would the expenditure, that is short-term loss, from compensating owners' exploded headphones be worth it to maintain the reputation of the brand? If such a policy is implemented, could there be implications in the future if amplifiers that continue to explode headphones? And if this is a concern, what additional safeguards can be designed into the products to mitigate the risks and how much will this add to the price?

    People like to talk about Schiit-gate, but the truth, as @Psalmanazar said, is that a few seconds of DC to 0, will not kill drivers. However, what was demonstrated became a matter of mass hysteria, and many folks probably reported Schiit amps killing their headphones when their amps may not have been the cause. Schiit ate it anyway.

    Karma works both ways.
     
    Last edited: Jan 7, 2021
  14. purr1n

    purr1n Desire for betterer is endless.

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    I could care less about Topping.

    My concern is where is the objectivity and 60 Minutes exposé? Imagine if this happened with a Schiit product. ASR would be all over it. Photos would be posted. The pitchforks would have come out. Amir would be right on it.

    ASR members like to pride themselves on objectivity, at least this is what they say. However, objectivity cannot be opportunistic and have differing standards upon scope and depth of investigation. If one is going to score/rank gear and offer levels of recommendation, it's not just measurements, we need process, standards, and criteria.

    You can't say: he's a forum friend, so although this is a shitty measuring SS amp, get this if you want a tube amp instead; or I hate this company's marketing tactics, so I will turn up the magnification level on the microscope; or since I write glowing articles for these companies' holding company, I will ignore it when their amps explode headphones.

    True objectivity requires the human elements to be controlled.
     
    Last edited: Jan 7, 2021
  15. Brause

    Brause Friend

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    This apparently does not affect my friends in SE Asia as it is too humid and hot there. I was told it can be easily prevented by running an earth wire to ground the casing.

    Erm....I have an L30 on order. Wonder whether it will arrive pre-exploded...I don't believe in "burn-in" anyway :).
     
  16. purr1n

    purr1n Desire for betterer is endless.

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    This is assuming that it's ESD. We still have no idea what is the cause or if the cause the same. More data (photos) would help.

    Is the case metal or plastic? I cannot tell from the photos.
     
  17. Brause

    Brause Friend

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    I'd guess metal: can't ground a plastic casing.
     
  18. Baten

    Baten Friend

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    It's a metal case. The way the amp works is that the headphone driver is a piece of tpa6120, with a feedback loop using a piece of opa1612. If the TPA chip somehow burns out (failing chip or otherwise), amp is fried and will smell nasty but there should be no further damage. If for whatever reason the feedback-opa1612 fails you end up with the scorched thing pictured earlier in the thread and connected gear likely to be damaged beyond repair. As for the cause I'm not really sure, either parts not in spec or design failure, perhaps an untimely combo of the two (after all if protection was better built-in, it would simply fail and that'd be that).

    Full disclosure I own this amp for cheap pre-amp duties in the living room but will have it retired after reading this thread. it sounded fine though.. and yeah it's cheap.. but there's always a catch, in this case danger to your beloved gear. Too bad.
     
    Last edited: Jan 7, 2021
  19. M3NTAL

    M3NTAL Friend

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    I'm guessing ESD too. The amp was sitting on carpet when I turned it on. The board isn't grounded to the chassis in any way that I saw. Nut on the vol. pot only, but not tied to chassis.
     
  20. Cspirou

    Cspirou They call me Sparky

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    With the opamp near the case it could be ESD.
     

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