Sennheiser PC37X randomly goes bad after disconnecting the cable ?
Greetings, Yesterday I was using my headset like normal with my macbook, just listening to music and on a call with people like usual, and the headset was perfectly fine. The stock wire that came with the headset is extremely long and yesterday it annoyed me very much that it kept getting tangled with itself, so I decided to see if the cable is replaceable. I pulled out the cable from the headset and saw the adapter, and looked online for a replacement. Upon plugging it back in, the audio sounded extremely muffled and washed out. Im not sure what I did wrong to make it mess up like that as I've always taken good care of it, ive had it for about 2 years and its always just been chilling on my desk, but anywho I thought the cable just went bad and ordered a replacement. The replacement came, and the issue is still persistant, so I am not sure what the issue is I've tried multiple different headsets and the issue is not with the port, and I also tried it with my windows laptop and...
Apr 23, 2024
Below is a list of all of the changes that are different from the original spec. This list is from an extremely reliable source. I realize the final design is subject to change (red flag), but it seems obvious that they have no intention of sticking to the license.
"R25 - 5% instead of 1% - Impacts power management. More likely to cycle on off when batteries are low.
Blue LED - Requires power management circuit changes.
'Finally, the LED’s forward voltage is a critical element of the power management circuit. You can't change to a different color (especially white or blue) without making other changes as that will require more current and the different forward voltage means the power management circuit has to be altered.'
C13/C14 - WIMA 1.5uF present instead of 2.2uf. This is a critical audio path capacitor. The smaller value here will impact low frequency response! This is a serious alteration with performance implications. WIMA costs more, but red capacitors sell better than grey. Reducing value reduces cost (and performance).
R1/R2 - Generic charging resistors are present.
C6, C7, C10, C15, C17, C18 - Film caps have been replaced with generic parts.
C1 - Replaced with generic part.
C16, C21 - Ceramic caps have been replaced with film parts.
VR1 - Alps RK097 series potentiometer with 15A taper has been swapped for a lower cost part (unknown volume taper and balance).
Q1 Q2 - Power supply MOSFETS differ from standard parts. Q1 and Q2 are critical parts which affect opamp performance and turn on/off behavior. Discussed extensively in original article."
"Our take", "honoring the spirit of the design", "as much as we possibly can".... There is no "our take". There is NwAvGuy's take. Anything other than that is a violation. "Honoring the spirit", I read that as "we'll change what we need to, but we honor it", again in violation. "As much as we possibly can"..How much exactly is that? Are there obsolete parts in the BOM? (IIRC only the AC jack is discontinued). Why did they need to make a prototype for a known design, while admittedly not using the specified parts? O2's design is pretty specific. All amps should measure the same within mfg tolerances.
It would be nice if Massdrop is more transparent about what is going on exactly. I also hope we will see more testing done, because the numbers Will has posted is not enough. Ideally, there really needs to be a much more detailed engineering test report including test methodology and raw data. Otherwise, the numbers could have been fabricated (possibility, not accusation). It's also making me wonder why Massdrop sent the prototype off to Grace Design for testing, if the design wasn't already close to final.
Anyways, as NwAvGuy says, "the idea is the best implementations of the O2 should win." As long as there are no compromises to quality and performance, this would certainly be a win for everyone.
I'm in line with the comments that this should be named something else, as O2 is a very specific performance and board; I would expect an O2, not an O2-ish amp, so I think the title is misleading if the BOM is different. I have retracted my support for this drop.
I didn't mention this earlier, because it is engaging in hearsay, but my source also told me that Yoyodyne Consulting Inc., the owner of the ObjectiveDAC license, is so furious about this development that they may pull the license for the ODAC to prevent something similar happening to that design. I do all of my audio editing through an ODAC and it is one of my most valued pieces of kit. I would hate to see that design go away just because Massdrop wants to squeeze out a little more profit, rather than simply partnering with one of the licensed manufactures of these products.
To say this drop is having a chilling effect on the open source audiophile community is not hyperbole.
Thanks for your posts! Seems like there's a big question on lots of people's minds ( re: @ybz90, @zoomorph, and many others ) that I'd like to answer.
Q: Are the O2s being produced exactly the O2 as defined by NwAvGuy's original BOM? A: Yes, the O2s everyone is purchasing in this drop will be built the with electronic components specified in NwAvGuy's original BOM.
It's clear there's a lot of confusion around this but hopefully that provides the clarification everyone is looking for. If you buy an O2 on Massdrop, you will receive an O2 made to NwAvGuy's spec as mandated by the O2's license.
Let me know if you have any questions about this, I'll be around all afternoon and evening addressing all the great suggestions we've seen in this discussion thread over the last couple days.
One thing that's still unclear is what is meant by everyone's opinion has the potential to impact the final design (and this vague statement in the product description may have exacerbated this confusion over parts being used in the Massdrop O2). There are even suggestions that would never make it into the O2 because of the significant modifications necessary (and violating the license at the same time). I would assume "design" really meant choice of finish and whether symbols or text was used, but what about optional things such as 1/4 jack, RCA jacks, rear power jacks, etc?
I understand what you are saying about the O2. However, if we stick with a strict interpretation of no derivatives, no modifications, then was it legal for JDS Labs to make the v1.1b O2? At what point is it legal and not legal?
I should make this clear - I am not saying anyone should start swapping components.
I'm still thinking about this, and I re-read NwAvGuy's comments on commercial implementations. It is clear to me now that no modifications should be made if the product is to be sold commercially. I may have been confusing this with DIY implementations. So I guess when some parts are no longer in production, we'll all have to build the O2 ourselves.
What is the general consensus of this build right now?
I certainly think that if the LED was changed to blue instead of red, it will make a significant impact on the performance of the O2 (blue LEDs often, if not always, have larger forward voltage drops than red). I also certainly do not wish to imply that someone should "improve" the O2 and sell it.
"I believe John at JDS made comments to the effect that NwAvGuy's reasoning is to avoid the production of pseudo-O2s with highly variable reliability and performance, which in turn, would reflect poorly upon the design in general."
I wholeheartedly agree.
Thanks for your post! There are definitely a lot of moving parts for this drop and the idea of adding another tab as a sort of FAQ section has been discussed and debated internally.
In the future, these types of custom products will have a different kind of page associated with them where it'll be easier for community members to contribute and answer common questions for the group.
Let me know if you have any specific questions going forward, glad to answer.
What are the chances that the final drop will incorporate 1) rear power jack and/or 2) rear input?
Thanks
Merci pour la réponse! Alright, now that we've exhausted my high school french, that's a great question about the "impact on final design" point.
When I posted that, I intended it to focus on the cosmetic aspects of the product (front panel material and printing primarily as you guessed) but there's been a ton of people asking for more structural changes (different gain options, moving input/powers, etc) and we're checking with our manufacturing partner but I expect any sizable revisions like that would incur meaningful additional wait time. All the ppl requesting a non-red LED are out of luck because of license sadly.
I'll be posting an update on this once we have more info, but again, I'd say there's more to be done with the purely cosmetic stuff than with the bigger structural points.
Appreciate you taking the time to respond to my post! Interesting point you bring up about posts contradicting each other, not my intention, and I'm not sure where the specific contradiction lies. If you're referring to this post: https://www.massdrop.com/buy/massdrop-o2-amplifier/talk/238649 where I say "The final unit will have everything as close to spec as we can get", it's worth knowing that the closest we can get is exactly the spec.
At this point I hope it's clear that we've planned to honor NwAvGuy's spec and license since the beginning (given our track record of honorably handling community designed products, re Ergodox, Infinity Keyboards, and community designed keycap sets in the mechanical keyboards community) but I can also see why my initial wording could be cause for concern.
That said, letting our contract manufacturer sub in some alternative parts to get us a prototype for pictures was definitely a poor choice we won't be making again. Think of how much pain and suffering could have been avoided if we'd waited the additional couple weeks it would have taken for sample quantities of all the proper parts to reach the manufacturer. Lesson learned there for sure.
Do you think it would be best to remove the PCB photos up right now to avoid confusion? Obviously it'd be best to post pictures of a PCB from our contract manufacturer with all the parts according to spec, but there's probably not enough time in this drop to make that happen... Actually, probably easier to add some notes on the pictures to avoid confusion instead. Let me know your thoughts on this.
Overall, I don't think you'll find me apprehensive to acknowledge the incredible work you and other community members do in discussions and polls. Much the opposite actually, this community is what makes Massdrop worthwhile IMO. Posts like yours, with intense attention to detail and strong opinions make for far better discussion than a predictable hype train.
It's been our goal from day one to give the community credit where deserving (as we have in the past when we've adjusted our course of action based on overwhelming community feedback, see this drop discussion https://www.massdrop.com/buy/corsair-rgb-gaming-keyboard-and-mouse), sadly, all this confusion is the result of my poor wording choices, for that I am sorry.
All in, you can be sure we'll continue to honor open source licensing, and I'll have a couple more people look over my choice of words before posting on sensitive topics : )
Initially we intended for the "suggest changes" to focus on cosmetic details associated with the front panel, that said, it's clear there's a lot of interest in rear power and rear inputs.
As such, we're checking with our manufacturing partner, but it looks like incorporating a substantial change like that would increase lead time meaningfully.
I hope to have an update on this shortly.
What are the power specifications for the amp? There are a few of us from Australia that are looking at this but we have 240 voltage here. Will it work fine?
Thanks
Many of us I'm sure would have no problem waiting just a little bit longer if it meant getting a better overall product at the end of the day. Especially if you incorporated some of the popular changes suggested like the rear power jack.
Thanks for clarifying.
"These prototypes were constructed using parts immediately available. That’s why there are some deviations from the original design. We are still adjusting the design (those details I mentioned in my original post), and we will be updating the group with any major revisions here in the discussion. Those final design elements will be decided shortly before the drop ends (we’ll release the changes in an email to all participants ."
"This means every piece feedback we receive has a very real chance of making into production."
"The intention with our take on the Objective 2 amplifier is to make the product accessible to more people while honoring the spirit of the design as well as the licensing terms as much as we possibly can."
"The followup question is "Then why do other companies have O2s with different outputs and inputs?" and the answer is, as far as we can tell, they're not obeying the rules of the license. Feel free to jump in and tell us if you know better."
Basically, any reader of those comments would get the impression that Massdrop is NOT planning to follow the design and license exactly. We see discussion about making adjustments and revisions, which would be unnecessary if following the specifications. We see requests for feedback and suggestions, implying that the design is open for change. We see vague claims to want to honor the "spirit" of the license, rather than honor the license itself. We see a desire to honor the license "as much as possible", rather than simply to honor it. Finally, we see that other companies have already broken the license, in your opinion, which begs the question of whether it would be OK for Massdrop to break it too.
So many vague words. So much uncertainty and doubt. You're trying to tell us that it was not intentional and that you always meant what you didn't say. If true, then that's a mistake on par with publishing pictures of the prototype using the wrong components. But does anyone actually believe that, or do we all believe that you meant what you said, were intentionally ambiguous, and only made up your mind after all of the negative feedback? :-)
Anyways, I'm glad that you've now settled this and vowed to follow the specifications exactly for the final product. I hope that you'll have the final prototype reviewed for correctness just to be sure.
Then, there were the marketing images you posted on the description page. They are so clear that you can identify most of the replacement parts. Again, adding to the suspicion that the license will not be adhered to. I mean, there is a shinning blue LED in the very first image! Anyone who has followed NwAvGuy would immediately know something was amiss without even looking inside the case.
Some of your posts also contributed to the confusion. I don't want to belabor the point, but here are some examples:
"the final unit will have everything as close to spec as we can get" - You are either compliant with the license or you aren't. There is no reason why the device can't be made to the exact specification outlined in the license.
"We are still adjusting the design" - Again, the design is what it is. It's all spelled out in the license.
"Those final design elements will be decided shortly before the drop ends" - Lends to uncertainty that we are, in fact, going to get a genuine O2 as dictated by the license.
"every piece feedback we receive has a very real chance of making into production" - Many of the suggestions offered would violate the license. They should have NO chance of making it into the final product.
"honoring the spirit of the design as well as the licensing terms as much as we possibly can" - Honoring the spirit of the design is an amorphous concept. This is electrical engineering. You either followed the design or you didn't. The same with the licensing terms. If other manufacturers have been able to adhere to the license, then you can too.
I realize that the quotes I referenced are out of context, but you basically hit every no-no word you possibly could. When you use words and images like those you chose it can't help but ruffle feathers. Despite all of the licensing, open source really depends on the honor system.
Don't touch what I say you can't. Change anything else you want. Give it to whomever you choose.
If you mess with that first point you undermine the willingness of people to release things as open source. Why should anyone attach their name and reputation to a design or piece of software, for no profit, if no one will respect the license. This device is just one small example. Imagine what a different place the world would be if Linux were never released.
All of this confusion could have been avoided by simply stating from the beginning that you were offering a fully compliant O2. No talk of prototypes or pictures of cases full of the wrong parts. At this point, I have no choice but to take you at your word. And I am happy to do so. But you better believe after the craziness of this thread people will be cracking open their O2 to see what's inside. I sincerely hope they aren't disappointed.
If your problem now is the confusion that the pictures represent and Will's original words, you can always not buy this product and go spend $150 (or more) on the JDSLabs or Mayflower version.
I'm personally more than happy with this offering, since it's the first time I see this product on the more affordable side of things. At $150 I would not call this product a giant killer at all and IMO a violation to NwAvGuy original claims of offering an affordable product. It also goes to show profit margins of other manufacturers.
When I get this product I will check it out and characterize it as best as I can. And I'm fairly sure Massdrop will deliver the goods.
I also love the box and volume knob of this version... and that it's black.
I think I saw the Mayflower one for more than $100, but it's currently on sale for $100. I wonder why (Massdrop maybe?). I mean, their DIY O2 is $95...
Building your own I think was more than $46.33 after you buy the custom case, unless you machine it yourself.
Yup, I think you've encapsulated the point well. Nobody should be disappointed with the final result.
After our experience working with products designed by the mechanical keyboard community, I expect to see a number of posts with people converting these units into DIY kits to check for part consistency.
Thanks again for taking the time to post and have this discussion. There was a time not too long ago where I was debating with the other two Massdrop employees (we've experienced a bit of growth since then) about whether or not people would ever be interested in posting in a Massdrop discussion.
The fact that these conversations can happen on Massdrop is amazing and I'd never trade it for the kind of standard "follow me, follow back", "this product is great A++" fluff you see in almost all product page related discussions.
You can count me among those endorsing your posts.
Yep, I hear you. Check out Zoomorph's post here: https://www.massdrop.com/buy/massdrop-o2-amplifier/talk#!242441
I'm checking into whether or not this is possible. seems like this would give us the best of both worlds.
They basically say that modding doesn't immediately void your warranty, but they wont cover warranty replacements for units where the modding resulted in the unit breaking (and they get to make that determination). Generally, especially with these types of mods, it would be pretty easy to figure out if someone's mod resulted in their unit breaking.
Anyway, this is all speculation until we figure out if this semi-DIY option is a possibility. Stay tuned for updates.
It's definitely been more interesting than if it had been a discussion full of "REAR POWER!"
Also, after reading a lot of posts. Will there be a 240v version?
R17 = R16/(Av-1) = 1500/(Av-1)
Where Av represents gain
For gain of 10x: R17 = 1500/(10-1) = 1500/9 = 166.67 ohms The closest 1% tolerance resistor is 165 ohms.
If I am buying this I expect it to follow Nwavguy's original design and performance. If I am not guaranteed this I will cancel the order.
From reading Will's post I am still unsure if this will follow the original design or not.