Massdrop x Airist Audio R-2R DAC Discussions | Drop

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Massdrop x Airist Audio R-2R DAC

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Showing 1 of 345 conversations about:

Massdrop x Airist Audio R-2R DAC

Will

8470

Chief Product Officer

Jun 10, 2018

Hey Friends, I was hoping to avoid making another post on this topic, but given sosolar’s most recent posts, I feel it’s necessary to summarize and clarify the statements and claims made. Sosolar surfaced in the Massdrop RDAC discussion at the beginning of the week, claiming the RDAC was a copy of his Hibiki project. A lot of people got excited by this, maybe not understanding all the details, but seeing the layouts of the PCBs looked the same, and accepting that as proof of sosolar’s claims. Seeing that post, we (Massdrop) were surprised to see the similarities as well. We were unfamiliar with the hibiki DAC, and we didn’t play a role in the development of that top PCB, so we reached out to William at Airist. He let us know he wasn’t familiar with the project either, and was reaching out to his engineering manager to get more information (thus the post from William explaining reference designs and saying he was unfamiliar with the hibiki DAC). At this stage, we needed to get details from the engineering manager and the contract engineers he hired to work on this project. The layouts looked the same as the RDAC, but the arrangement of some parts was different, and the spacing between parts was also different. That’s all we knew at the time. Sosolar continued to feed the discussion, making further claims, and posting details of his project on various discussion boards, talking about releasing a product and gathering feedback. At this point, I had already provided my contact information as a direct response to his comment on our discussion, and received no response. While this was happening, we were able to speak with the engineering manager from Airist and his contract engineer. The engineer explained his process; initially he was provided with a set of specifications, a mandate for a ladder arrangement that would meet the specs of William’s overall design (the top PCB represents ~25% of the overall RDAC design). Given that mandate, he began searching for reference material, and discovered this reference design posted for free use (says that on the post) in 2014: http://bbs.hifidiy.net/forum.php?mod=viewthread&tid=994769 From the basis of this reference design, he looked for examples of layouts that could provide a good baseline, while allowing him to build the underlying structure to serve the purpose of William’s design. Important note here, PCBs have multiple layers, the top board of the RDAC has four. The top layer is where components are positioned, but the content of the other layers determine how those components interact. At this point, the engineer found the Hibiki DAC, and while the same configuration of parts wouldn’t yield the desired result, the general layout would work for this project, so he used it as a reference and creating the RDAC top PCB layout. This is why it looks the same, and why we subsequently posted as much in our discussion. My wording could have been more direct, but it’s not an exact copy, so “inspired by” seemed like the best option, but ultimately it was more confusing than clarifying. The position of parts is nearly the same, but sosolar continued to post, accusing Airist’s team of reverse engineering the board, which isn’t the case. From there, still having received no contact from sosolar, I reached out to the email address associated with his Massdrop account, explaining that I’d like to understand exactly what he’s saying, and to understand more about the Hibiki project in general. Now I want to pause here, and make clear an important understanding in professional communication. Emails are intended for the specified recipients, and it’s bad form to break that trust. I won’t be posting screenshots or exact wording from his message, but following sosolar’s most recent posts I feel it’s important to share some of the general themes in our communication. He responded to my messaging with a development timeline for the Hibiki DAC, starting in June 2015 and ending in July 2016, and demanded that we post a comparable timeline for RDAC development. His timeline had great detail, with lots of links to posts and things of that nature, which makes sense given the Hibiki was developed publicly, with sosolar sharing details with the hifidiy.net community. It’d be nice if posting a timeline would answer the questions at hand, but the RDAC development was private, there are no public posts to verify the statement. Given the many responses from people saying they didn’t believe our previous statements, I didn’t think an unverifiable timeline would answer questions for anybody. The most important part of Sosolar’s response, was around some parts in the design he said were unnecessary, essentially saying they were stylistic choices on his part, that wouldn’t exist on another board unless the functionality was being copied through a reverse engineering service. All of these parts which are unnecessary for the HIbiki, but are critical to the function of the RDAC. We answered all of Sosolar’s questions directly, here is the explanation we provided for each of the sections sosolar called out: For the op amps: The op amps on the RDAC top board are not just buffers, they are necessary for the operation of a sign-magnitude ladder. The output from a network of so many resistors is very weak, so we have to bring that signal strength up or else further processing will drown it in noise. These op amps do that amplifying, merge the outputs from the positive and negative ladders into one output waveform, and filter out the switching artifacts. For the large transistors: Because the R-2R ladder is basically a 48 resistor network on each side, you need a fair amount of current to actually drive the whole thing, not to mention extra overhead. For the logic switches: These are the same switches used in the open source schematic posted in 2014, and that is how the engineer picked this part. Sosolar’s response to this message said that he was waiting for us to post the timeline, followed by a sentence that I think was trying to suggest he wasn’t accusing Airist of reverse engineering and copying the DAC design, but the layout alone (not trying to knock his english, I don’t write a character of chinese, but I couldn’t understand his wording) which would be a change from his previous statements, but I can’t be sure. Hopefully we can talk about this on the phone where mandarin/cantonese speaking team members can remove the language barrier in this technical discussion. I responded to his message early this morning, hoping to catch him still awake so we could have a call, and in that email I proposed a solution that would give clarity to the community. We could both provide our gerber files to an unbiased third party (I suggested the new editor of IF, guy has no skin in this, and I’ve been asking folks for his contact info today in an effort to reach out and see if he could do this), they can examine the files and tell the community if the RDAC top pcb is a copy of the Hibiki pcb. I haven’t received a response from sosolar, but it’ll be morning in China soon, so hopefully sosolar is game for what seems like a pretty amenable situation. TL;DR Overall the layout of parts on the hibiki DAC and the top board of the RDAC are nearly the same. Neither Massdrop or William Tse of Airist was aware of the Hibiki DAC before sosolar’s post on Massdrop. The layout is not 1:1, but it’s clearly close enough where folks feel it’s essentially 1:1. We’ve explained how the hibiki layout was used by Airist’s contract engineer, and hats off to sosolar for creating a layout that works for the RDAC’s execution needs. If he had interest in compensation for this, he has plenty of avenues available to express that, as it stands, it seems he’s more interested in posting about the balanced hibiki he’s releasing this August. The similarities end at that top layer, and we’re glad to provide RDAC files for verification by an unbiased third party. We’re doing everything we can to resolve this amicably, and we’ll keep trying, hopefully sosolar will engage with us.
Original Post: https://www.head-fi.org/threads/massdrop-x-airist-audio-r-2r-dac-a-discrete-resistor-ladder-dac-for-350.881315/page-12#post-14294445

Brian_Fu

Jun 10, 2018

WillAction speaks louder than words. The fact that the drop still went live despite the issues raised has given the impression that you guys are not taking this apparent intellectual property theft seriously.

JDWarner

349

Jun 10, 2018

Brian_FuYou... apparently missed the fact that nobody knew about any of this until after it went live.

Lawrenceho

Jun 11, 2018

JDWarner @JDWarner and you apparently missed the fact that it wasn’t nobody. people were discussing it here and on headfi long before it went live.
after all these days and even Will himself admits one of the engineers that Airist hired, got inspired by sosolars‘ work. What matters right now is such inspiration legal or not and it is not up to us to judge.
Meanwhile, any decent company would suspend the drop to save their reputation, though MD is doing quite the opposite. Also I am sorry to see how they responded to @inorbit8’s questions...

Artifiz

180

Jun 11, 2018

LawrencehoYep, nobody can't copy anyone's idea and present it as his/her own, that's plagiarism and its definitely a wrong doing. I also understand Massdrop has nothing to do or fear (at the moment), but there is clear reasonable doubt to stop the drop and keep away from Airist and their smart a** engineer. On the other hand I wouldn't join this drop. Looking at Airist's character, I would be afraid they(Airist) will change the whole thing to prove the other guy wrong.

Lawrenceho

Jun 11, 2018

Artifiz @Artifizthere was a moment I thought they would change the pcb layout. However on a second thought I believe they will not. coz it is probably unacceptable to people who have joined this drop.

nwimpney

219

Jun 11, 2018

Willregarding the opamps. You're basically describing a buffer. A buffer is just an amp without voltage gain for strengthening weak signals. I can't tell without seeing the schematic whether either one is appling gain, but either way, that's not really a difference worthy of mention with regard to whether the board is a copy or not. Rergarding the inner layers of the pcb: They're not significantly changing the way the board operates in any way. You don't arbitrarily lay out components and then connect them with a mess of spaghetti on hidden layers. It might be an improvement adding ground and power layers, and it might allow better routing of a few things, but it's still fundentally the same layout.

zbells

234

Jun 12, 2018

WillGood post Will and love the idea of sending the boards to a third party arbitrator! Seems like a reasonable solution for the dispute.

ajaxender12

Jun 13, 2018

WillIf I'm understanding this correctly: - the top PCB is the 'R-2R' bit, and that itself is not a remotely new idea; that is, the concept of 'R-2R' is not novel and is not owned by anyone, so the overall purpose of this board does not (and cannot) infringe on anything. And, just as with chip DACs eg AK, ESS, the overall implementation across the entire product is far more meaningful than basic pure digital to analogue conversion process. - but, that specific layout for the PCB was designed by sosolar, and subsequently used in the development of this overall product.
My question here would be, what is the benefit of that layout? Is it simply a nice layout for an 'R-2R' design, and a different one (eg as shown in William Tse's post) could, essentially, be substituted? Or is there a tangible benefit to this product in using that layout?
Regardless of the answer to that, the part of your post that doesn't sit well with me is "If he had interest in compensation for this, he has plenty of avenues available to express that". Considering you have discovered his design was indeed used, to any meaningful degree, in this product and freely admit that, is it not on you (or your side as a whole) to approach him about compensation? If my above reasoning is correct, I do not feel that it is right to call this product 'IP theft' or a 'copy', but nor does it feel right to simply act as if sosolar was never involved and leaving it entirely up to him to force you to do otherwise.
I remain interested in this because I have sufficient trust in those who have heard it and posted about it, the whole debacle has informed me about the concept and point of R-2R (all publicity = good publicity, etc etc), and it is simply a cheaper (but therefore, of course, potentially inferior) way to experience R-2R than other products (such as from sosolar himself, if his posts elsewhere hold true). Please continue communications with both sosolar and the public.

livingspeedbump

6723

KeyChatter’s Owner and Editor-in-Chief

Jun 13, 2018

WillThanks @Will ! Great answer and action on part of MD!

Tex1954

Jun 14, 2018

WillHi Will, legobatman down below has a good question about the firmware as to how it might get update etc. Perhaps you might get time to respond.

RockyMountains

478

Jun 22, 2018

JDWarnerJDWarner You... apparently missed the fact that nobody knew about any of this until after it went live.
This all blew up about 2 days before it went live on a couple of headphone forums. The drop went live anyway.

GunsOfBrixton

911

Jun 29, 2018

WillI've had my bucket of popcorn out watching this discussion - and let me say clearly, without the legal or engineering expertise needed to know who's right or wrong here. I suspect that applies to most of the commenters here as well, on both sides of the issue.
Stealing someone's engineering work and profiting off of it is an ethical problem. But so is accusing someone of intellectual theft, if it's not true. It looks like MD took a hit on sales here, and maybe rightly so - I'm OK with the market making that decision when there is doubt. But I'm also respectful of the fact that there are real people who work for Massdrop that, like most of us, are trying to make an honest living in a competitive world. Calling, or implying that, people are thieves is a crappy thing to do too, if they aren't.
I'm satisfied with MD's offer to share their work with an independent third party to test what's under the hood and compare it to sosolar's. If the similarities are ultimately superficial, as MD claims, then people can respond appropriately based on verified information. They could buy comfortably knowing it wasn't a stolen board, or choose not to buy because it used the visible layout of another product. Either would be a perfectly legitimate response.
I hope I've just missed the part where sosolar took Massdrop up on their offer. Because otherwise, it would look an awful lot like smearing someone's character, then vanishing when called on to verify it or set the record straight. I want to presume the good intentions of all parties here, so hopefully the third party verification happens. But if sosolar vanishes, that would speak volumes.

Will

8470

Chief Product Officer

Aug 10, 2018

GunsOfBrixtonSosolar did not respond to my email offering to make the comparison. He/she has not contacted me or anyone at Massdrop since. It also appears they have left the english speaking forums where they were posting when this product launched.

GunsOfBrixton

911

Aug 10, 2018

WillThanks for the update Will. As I said before, that speaks volumes about the merit of the claims.

nwimpney

219

Aug 10, 2018

GunsOfBrixtonI don't think it really says anything about the "merit of the claims" it just says that he knows that he's not going to get anything for his troubles, regardless of what the independent 3rd party says.
I have no doubt that the board was fairly closely copied, whether from the source files or gerbers, or just manually traced out. There's no other way it would end up that similar. Anyone who's done any PCB design can tell you that.
Who knows what Sosolar wanted. I don't think he was after any money, or he would have made a bigger deal of it. Probably he just popped in to say WTF when he saw his work copied. I know if I saw one of my board designs show up in someone else's device, I would certainly pop in to ask some questions.
I'm glad he dropped by, because it tells me some things about Airist which are good to know, before deciding what to spend my money on.

DavidLonghorn

116

Aug 14, 2018

WillI would like to respond as an "average" consumer in this product category with strong rational capability, low average for expertise in the technical parts of this discussion, but also trying to inject a significant element of common sense. In general, I absolutely support the value of integrity and respect for what people produce through their own talents and effort, but I think the engineers and experts here are getting too intense and overreaching with their arguments about the legitimacy of this Airist product. I think those of you in this group need to back away from your slide-rules, drop the condescending attitudes about your moral "high ground" and stop acting like this is a "case closed" ethical determination based on "appearing to be" an exact copy of sosolar work/product. You are only presenting a personal philosophy with no legal, objective determination... and you are absolutely entitled to that attitude for yourself and even to discuss that this is your reason....but it is no different than stating that you won't buy products made in China (for whatever reason).
This is completely different than where people manufacture products to take advantage of another's reputation, brand or market by claiming their appearance without delivering the performance and selling at a price to skim the market. As I understand this product, the source is a long-term technology with a generally available template and with numerous entities looking to produce their vision of a product that uses the techniques and factors of the technology. The only way to protect "proprietary" development is with a patent! I get that it is expensive and hard to justify, but otherwise there is no claim to "ownership". Period, End game.
Now, if you engineers or others with more of your life force invested in the deep places of this business want to have your own personal calculations and philosophies to determine what is "best" for you - then you should use those to decide - for you. Otherwise, it seems to me that Airist (in their determination) have just built a better mousetrap and are presenting it in their own right for customers to decide with no interest in relating their product to what sosolar did or didn't do to create their separate product. I wish you technical experts, who I respect your objective knowledge and information, would concentrate on specific analysis of performance items and not provide so much "color commentary" which is diminishing your potential contribution and making you seem spiteful and full of agenda in your discussions. It actually makes me greatly discount any of your (hopefully) legitimate input.
Thanks for your consideration.

Wamcky

Aug 17, 2018

DavidLonghorn+1 Could the armchair lawyers move on if your not interested in a purchase so those that are can get back to discussion of the unit itself? I'm sure sosolar is a big boy, and can handled his own matters without the internet 2 cents machine.