Do I really need to get out the soldering-iron again?

I have a pair of powered studio monitors (Mackie MR5), and I completely relate to this problem. Many PCs and phones will emit an audible hissing noise while plugged in. I&#x27;ve tested on a dozen different devices, with integrated and external DACs, five hundred dollar sound cards, massively shielded cables, practically every modern OS you can name, tweaking every audio setting exposed to me. The only devices that work perfectly are (1) my TV output, and (2) every single Apple product.<p>I&#x27;m wholly convinced that the computing world is, in general, regressing. Audio has been a huge loser in this fight. Today, many modern phones don&#x27;t ship with 3.5mm jacks. If you want lossless audio, you literally can&#x27;t find it, even though there&#x27;s zero reason companies like Spotify couldn&#x27;t stream it when available (even if it costs extra) (Spotify literally asks artists to upload the masters when they publish, they have that data and then throw it away). Many artists don&#x27;t even publish physical CDs anymore, so its a game of luck if they have a website where I can buy the FLACs&#x2F;ALACs. And if you want the actual files to, you know, live your life in a completely legal way, those are gone.<p>Its more than just audio. Watching movies sucks; you now pay full price to effectively indefinitely rent movies, and have them taken away at any time. eBooks are the same and always have been; the world&#x27;s oldest technology has been coopted by companies like Amazon to increase revenue, and there&#x27;s practically zero competition. Applications suck; we&#x27;re puking web and electron everywhere, eating up every conceivable megabyte of memory available literally only because developers are lazy, and now you&#x27;re consistently asked to pay a monthly fee to access this functionality literally only because companies are lazy. Modern operating systems suck; restricting filesystem access, exposing proprietary application APIs which fundamentally make applications unportable and thus contributing to the rise of Electron&#x2F;RN.<p>Somehow we took systems and workflows that were amazing throughout the 90s-00s and, in the course of a decade, completely ruined them.

Interesting point buried in here: since Android is open source, you could go in and fix the bug, but then because you&#x27;re not running an official Android version you&#x27;d lose access to the Play Store and other services. Something&#x27;s not really free if there&#x27;s a penalty for doing it. Since freedom to run a modified version of software yourself is one of the four freedoms of free software, this highlights the difference between free software and open source.<p>I&#x27;m not saying open source is bad and everyone should prefer free software. It&#x27;s just a good example of the difference between the two in practice rather than in some debate about licenses and the abstract principles behind them.

<i>&gt; Right now I&#x27;m absolutely astonished at how difficult it appears to be to just listen to music with a good pair of headphones. Is it not 2018? The media is full of talk about preposterously ambitious ideas such as AI and self-driving cars and yet I can&#x27;t even listen to a fuck-damn music track? O_o</i><p>I enjoyed reading this. The whole time I thought however: that’s not an issue on my Apple devices. Then I read:<p><i>&gt; If anyone reads this post I&#x27;m sure loads of people will tell me that my problems are all my own making and if only I invested in an iPhone all my problems would go away. Well you know what? APPLE IS A SYMBOL OF PRETENTIOUSNESS AND IGNORANCE - YOU DO NOT EVEN KNOW HOW YOUR PHONE WORKS - I DO NOT HAVE TO PAY A TAX TO APPLE TO LISTEN TO MY MUSIC.</i><p>Well, at least it usually simply works.

&gt; _It turns out that all music players on Android actually play music using the Android-media-player-service._<p>This is inaccurate. Neutron music player bypasses Android&#x27;s Media Player APIs and talks directly to your DAC and plays music without resampling (if the DAC supports it). Never had any audio popping or explosions using Neutron, and I&#x27;ve tried it on 6 different devices so far without any issues (LG G3, Nexus 6P, Nextbit Robin, OnePlus 3, Note 8, OnePlus 6). My headphones are a Beyerdynamic DT880.

IMHO your circuit topology looks wacky. Perhaps there&#x27;s a goal to making your amplifier ground ride in the middle of the waveform, but it could just as well be unintentional. So my immediate thoughts -<p>You&#x27;ve already got a real split supply with 2x 9v batteries. If you use that instead of deriving a virtual ground, you will save 9mA of quiescent current.<p>How purposeful is that whole low side duplicated circuit and why? [0] It seems like since you&#x27;re using batteries, hooking signal ground directly to your ground and driving the output single ended would work fine. Or if you want to work towards being able to AC-power, then a differential input op-amp topology and still drive the output single ended.<p>Isn&#x27;t there a vibrant cottage industry of external USB DACs and headphone amplifiers and whatnot? I&#x27;m more of a receiver+speakers type of a person, but I often see newly designed stuff for headphones.<p>[0] Driving both sides does get you the ability to swing the output a full 36 volts. But given that your goal is to cut the signal by 11 and also that by mixing both channels you can&#x27;t actually do that lest you get crosstalk in the form of clipping, I don&#x27;t think this is your goal!

I’ll happily pay the “apple tax” so I can live my life and not have to deal with all the bullshit you did just to listen to some music. Good lord. I’d rather experience the world then mess around with the tech that’s supposed to be helping me live better.

&gt; YOU DO NOT EVEN KNOW HOW YOUR PHONE WORKS<p>I know it <i>does</i> work.<p>Would I prefer to have a more open phone and computer? Sure. At the cost of having to ever tinker with it? No.<p>I just switched my home built raspberry + HiFiBerry with expensive speakers to a simple closed Sonos system for the exact same problem the author had with linux, audio hardware, noise. Having something that just works and I don’t have to care how is a blessing and in the future that is where I’ll put my money. Ignorance is bliss.

Everyone seems to be seeing this as an Android vs. iOS debate, but I see it as a smartphone vs. dedicated device debate. If you&#x27;re serious enough about photography, you don&#x27;t complain about your smartphone camera&#x27;s limitations, you get yourself a DSLR and multiple lenses. So if you&#x27;re this serious about music, why not get a dedicated device? Look at what companies like HiBy and Hidizs are doing. I have, and my ears haven&#x27;t been this happy since the early aughts.

I&#x27;m a bit flabbergasted by all the &quot;wow this person just wasted all his free time fixing a nonexistent problem instead of just getting an iPhone&quot; on Hacker News of all places. Yes there&#x27;s an ideological bent to the whole exercise but that&#x27;s precisely the kind of passion you need to deep dive into creating your own audio device over a minor annoyance. Yes it&#x27;s clunky and expensive to maintain but you have to admire the commitment and technical expertise to build a working product from scratch.. It was an entertaining read and I&#x27;m sure a good mental jog for the author.

I&#x27;ll allow myself some generalization here.<p>I know several very smart and creative hardware technicians and system administrators. I admire them. I truly do. They are more independently thinking than most other programmers I know, are much more resistant to trends and fashion in technology, and rarely complain about the tech they must use. Throw Python, Perl, PHP, bash and what not at them, they can and will curse but will get the job done every time.<p>In that regard, they are hard-working and resourceful. And I have a lot of respect for them.<p>That being said, I cannot help but notice things common among all of those that I know or used to know:<p>- Apple hate without any regard for the advantages it gives you.<p>- They use 80-100% of their leisure time to tinker and work outside their main work hours. One of them recently got divorced by his wife. She said the guy barely spent any time with her. I don&#x27;t know if their relationship wasn&#x27;t sour before but still, it&#x27;s partially indicative.<p>- Obliviousness how Android is not the end-all-be-all of free software -- because it&#x27;s not; Android is PARTIALLY open-source and comes with a lot of strings attached. Flash a ROM and your warranty is voided. But to them, if you can tinker with your tech then you absolutely, factually, practically, and for all intents and purposes, are using free tech. Details like warranties and hours-long sessions to make basic functions work again be damned in the process.<p>- Complete disregard for convenience and utter lack of respect for others&#x27; time. As mentioned above, they usually spend most of their free time working, are not stressed out or burned out, are in good health shape, and find it mysterious that people might be exhausted and would just want to lie on the couch reading a favourite book -- or napping.<p>---<p>I am somewhat saddened to say the OP&#x27;s article confirms my bias towards hardware technicians. He&#x27;s undoubtedly smart and good at what he does but also heavily biased and lacks perspective.<p>I believe such resourceful people should be more open-minded. If he&#x27;s reading this, I hope he takes it as a constructive feedback from the sidelines and not bashing. All I am saying is that their attitude is not helping them being taken more seriously. If you turn a blind eye to nuances (case in point: Apple hate from his side) then you are not objective in your discussions.

Is this actually a bug in Android (confirmed by someone else on a different phone) or is it a bug in the implementation by this OEM? I haven&#x27;t experienced it but I also do not use this writer&#x27;s particular sound files.<p>I think the underlying point is very important. It does seem like quality has been sacrificed in many products to shave a few pennies off the BOM. Why should today&#x27;s portable CD players be substantially worse than the ones available in 1995? I get that they are asking $25 instead of $115. But SONY and Panasonic have left the market, leaving it to the drugstore quality ones, and they don&#x27;t appear to want to make a product that plays a clear sound.<p>As far as circuits are concerned, I can&#x27;t help but notice that a TI TPA6100A2 costs $1.11 at qty 1, and outputs stereo from a 1.6-5.5V single supply drawing a max of 50mw. This would substantially reduce the weight and power draw of his mini amp. A couple rechargable AA batteries would do.

”It improves sound quality by taking away the hard work of driving the dynamic load of the headphones from the device&quot;<p>Can anybody explain that please? What is this dynamic load whose driving is hard?

I love how people can do this type of stuff. Whenever I get out the soldering iron to fix any problems, I face a 50% chance of success against 50% chance of fucking it beyond repair. Well, I guess it fixes it in both cases...

A USB DAC+amp seems like the right answer if you <i>don&#x27;t</i> want to break out the soldering iron and don&#x27;t want to buy an Apple product. I just don&#x27;t think makers of commodity hardware have much incentive to spend money on good audio circuitry. But if their USB ports didn&#x27;t work, well, that would be a real problem. I have an earlier model of this:<p><a href="http:&#x2F;&#x2F;www.schiit.com&#x2F;products&#x2F;fulla-1" rel="nofollow">http:&#x2F;&#x2F;www.schiit.com&#x2F;products&#x2F;fulla-1</a><p>that delivers good audio quality (to my non-audiophile ears). The one I have is not perfect: there&#x27;s some static when you turn the volume knob (maybe a good design tradeoff at the price, I don&#x27;t know), and the metal edges on the enclosure were sharp enough that I took it apart and filed them down a bit (others might not have been bothered by this, but I was). But there sure isn&#x27;t any background hissing like there is with the built-in headphone jack on my Dell workstation.

Most modern laptops have more than decent audio output, but if more quality is needed one could buy a small external sound card for a lot less than €100. This one for example would fit easily in a notebook bag. <a href="https:&#x2F;&#x2F;www.thomann.de&#x2F;gb&#x2F;miditech_audiolink_light.htm" rel="nofollow">https:&#x2F;&#x2F;www.thomann.de&#x2F;gb&#x2F;miditech_audiolink_light.htm</a><p>About the article circuit, I &#x27;m not that sure the 5532 is a good part for headphone amps, unless the phones have a high impedance and resistance: they&#x27;re intended as preamplifiers (and very good ones) so they hardly can supply the current to fully drive phones, though I guess they can still be ok for listening to soft jazz in a quiet room:)

Could’ve spent $199 on an iPod, have high quality audio, load your own music, no “apple tax”.<p>Coincidentally I was looking for something like an ipod shuffle this week and it’s become almost impossible to find, beyond some cheap thrift-store MP3 players.

Have had 8 android phones.<p>Literally never heard anything like this.

I&#x27;m super curious…<p>a. What in these files triggers the explosion of noise (and whether other people have run into this or the author would mind sharing a representative problem file).<p>b. Whether an output attenuator (or &quot;resistor&quot;) would work to quiet the noise (edit: the hiss, not the explosion) without a powered circuit.

If he&#x27;s able to get that much of an improvement with 5532s, I&#x27;m curious what he could get if he used modern opamps. Granted, the 5532 has been the opamp to beat for sound quality for decades, but someone posting by the handle NwAvGuy dis a shootout of opamps comparing and measuring the specs that actually matter for quality audio use back in 2011[1]. That was 7 years ago, and the various component vendors have released some new devices since. I suspect a slight redesign using a 2068 for the gain stage and a 4556 for the buffers would do even better, and drain the batteries slower because of less quiescent current of modern devices.<p>The circuit design looks weird to me. Wouldn&#x27;t it be better to use a inverting setup on the opamp to get get some attenuation, and then feed the gain stages into a high-current opamp like the 4556 as a buffer to drive the headphones, or perhaps a transistor that&#x27;d be good at the job? And why are there a pair of parallel gain stages on the ground line? Why not just throw your gain stages on the signal lines, ground ground and let it be ground?<p>1. <a href="https:&#x2F;&#x2F;nwavguy.blogspot.com&#x2F;2011&#x2F;08&#x2F;op-amp-measurements.html" rel="nofollow">https:&#x2F;&#x2F;nwavguy.blogspot.com&#x2F;2011&#x2F;08&#x2F;op-amp-measurements.htm...</a>

<i>I DO NOT HAVE TO PAY A TAX TO APPLE TO LISTEN TO MY MUSIC.</i><p>Is it better to pay a tax to Google and not be able to listen to your music?<p>(I say that as an Android user who hasn&#x27;t run into this problem, though 90% of my listening is through streaming services, I still have all of my CD&#x27;s sitting on a hard drive, but they are all (as far as I know) available over streaming now, so I just use that)

Heh, I’ve had a Bluetooth set of earbuds from JBL for about 2 years and they’ve been providing great sound (and are really convenient as I work like an auto electrician a lot of the time and I can leave my phone in the toolbox). A good alternative perhaps besides building a portable amplifier.

Boy does this person need to look at the ‘good headphone’ market.<p>I paid (a very reasonable) $2k for a set of reference headphones and a suitable amp&#x2F;DAC to drive them.<p>I could have spent a lot more.<p>It <i>is</i> hard to drive a set of headphones with enough SQ to make them worthwhile.<p>You cannot plug a set of headphones into an Android phone and expect anything good to happen. And lots of DAPs suffer from software problems as well (lots of them are Android based...).<p>Getting good sound from a portable device, without software issues, is really only solved at the top end of the market ($700 - $4000).<p>It’s a bit easier if you want to use a computer as a source but far from cheap.

Can&#x27;t say I&#x27;ve ever had the explodey sound any of my Android phones through the audio jack. I&#x27;ve had it a handful of times with some bluetooth buds, but I&#x27;d just as soon chalk it up to their cheapness.<p>I <i>do</i> have the hissing sound he&#x27;s described when using my ATH-M50&#x27;s with my phone, and even my laptop. My solution (albeit more expensive than his DIY one) was to buy a portable DAC&#x2F;amp, specifically a Fiio E17[0]. It connects via USB&#x2F;micro&#x2F;C, and it&#x27;s worked on every laptop and Android phone I&#x27;ve had since the Samsung GSII. It also used to be able to dock with a separate desktop amp[1], until my dock broke. There are plenty of other portable, Android-compatible DAC&#x27;s that are not too expensive. It&#x27;s a bit of a bummer to feel like you need to pay for yet-another-piece-of-gear just so you can enjoy your audiophile headphones with your audiphile-quality music on the go, but sometimes that&#x27;s the price of fidelity.<p>[0]<a href="https:&#x2F;&#x2F;www.amazon.com&#x2F;FiiO-Alpen-Portable-Headphone-Amplifier&#x2F;dp&#x2F;B0070UFMOW&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.amazon.com&#x2F;FiiO-Alpen-Portable-Headphone-Amplifi...</a> [1]<a href="https:&#x2F;&#x2F;www.amazon.com&#x2F;FiiO-Desktop-Headphone-Amplifier-Dock&#x2F;dp&#x2F;B004M172FY&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.amazon.com&#x2F;FiiO-Desktop-Headphone-Amplifier-Dock...</a>

For &lt; $100, I got a USB device which is a DAC+PreAmp+HeadphoneAmp which works great with all Androids, iPhones and computers. I didn&#x27;t have to solder or breadboard.

Can anyone comment on what&#x27;s going on with the ground channel in the circuit here?<p>Seems like you would want to tie the input ground to the virtual ground between the two 9Vs and then maybe buffer the output ground, but this circuit doesn&#x27;t do that - it just replicates the L&#x2F;R chains twice between grounds.<p>Also, what&#x27;s the point of adding the two 9Vs and then splitting them again with the two 1k resistors? Why not just pull ground from in between the two 9Vs?

&gt; <i>Battery life is only a few hours unfortunately because the circuit draws an enormous idle current of 23mA :o</i><p>This is because the device is silly. Firstly, there is an unnecessary voltage divider for generating a reference voltage. It is too stiff (resistors are too low-valued at 1K + 1K). This provides a reference voltage that is conveyed to high impedance destinations. 18V into 2Kohms means this consumes 9 milliamps!<p>Secondly, the device contains a bizarre circuit that tries to amplify the GND-GND path, using two op-amps in parallel.<p>The numbers check out: 9 mA for the voltage divider, plus around 8 mA x 2 IC-s (typical value from datasheet): 25 mA.<p>Here is how we can fix things.<p>1. We have two batteries! That is a true dual voltage supply! We can just take the center reference voltage between the two batteries. By doing that we lose the voltage divider entirely, and save 9mA of supply current.<p>2. We can lose the GND-GND amplifier, and just provide a proper end-to-end galvanic ground connection. We eliminate a pair of op-amps, and thus an entire IC chip.<p>We&#x27;re now down to the current draw for a single NE5532.<p>3. Use a different op-amp. The NE5532 isn&#x27;t great for driving low impedances like headphones. There are op-amps that are better suited for this, <i>and</i> draw less quiescent current.

&gt; I do not have to pay a tax to apple to listen to my music.<p>Well, neither do I to be fair. I seriously dislike iTunes but it can take more input than just the store..<p>Regardless of the official Music player app there are third party ones, some of which are super simple (presenting a http upload on the network and allowing playback of uploaded media) or, in my case, Plex (with a plex pass for local sync)

I saw similar problems <i>creating</i> music and sounds: having “good” audio hardware means that <i>every sound flaw you have is now obvious and annoying</i>. I had to be much more careful. Frankly, good sound production and programming are both underrated, they are not trivial.

I had to dish out for Audioquests Dragonfly red just so I could enjoy my headphones on pc. The audio quality <i>is</i> really good but I can&#x27;t really endorse that as the general go-to solution since the price is quite steep. Would not go back, though.

Why does it use two opamps for the ground signal?

I&#x27;ve had this problem a lot with sensitive in-ear headphones. I guess it is a problem of dynamic range - the same amplifier has to drive insensitive and sensitive headphones, so to avoid being too quiet on the insensitive ones (definitely noticeable) they make them super-loud at the cost of easily audible noise when you&#x27;re using sensitive headphones on low volume.<p>I actually bought Google&#x27;s active USB-C audio dongle to solve this for my Mi A1. It works, but I think USB-C is not a good port for headphones. It isn&#x27;t robust enough - if you wiggle it around as if it were in your pocket you easily get glitches.

Odd that the author poses this question:<p><i>Maybe it doesn&#x27;t like the metadata in those tracks?</i><p>and doesn&#x27;t go on to discover the answer. If my ripping and encoding routine were doing something funky that causes problems I&#x27;d really want to know about it, and it wouldn&#x27;t require me to debug Android as the author implies.<p>It&#x27;s true enough that Android playback probably shouldn&#x27;t be glitching, but if the track metadata is invalid or pushing the limits of what you can do, whatever he&#x27;s doing to his tracks is likely to cause problems in places other than Android playback...

With all &quot;high quality&quot; audio matters like this - and compressed music - I genuinely don&#x27;t understand what the point is. I listen to a lot of different music (Pop, Jazz, Metal, Microtonal stuff etc.) through a lot of different mediums (Good preamps into really expensive amps etc., cheap headphones, overpriced headphones) an I honestly think the point of diminishing returns is at about £30.<p>For the price that some people spend on their audio gear, you could buy several musical instruments: A far more fulfilling (and sociable) use of too much money IMO.

Just buy an iPhone.<p>Oh no wait. No hole that decent headphones fit in.<p>Have a 6s with a dicky headphone hole and some nice HD25’s. Not sure where to go. I feel like my time on this planet is nearly over.

Could someone with more electronics experience than me explain the difference between the what the author made and a an off the shelf amp?

I think the author of the article just wanted to get out the soldering iron.. as otherwise a few minutes on a search engine would have revealed the existence of the CMOY headphone buffers and a plethora of similar devices for laptops and phones already out there, including ones with their own high quality DACs.. unless there is something I&#x27;m missing here?

I think one of the most fascinating relationships that humans have with technology is that we expect everything to just work and that’s the end-goal&#x2F;advertised dream. However it’s never been that way and for good reason. Between competing technologies and human interests the actually reality of technology is that it’s all broken.

&gt; Shame Maplin closed because now I have to order parts off the internet and WAIT.<p>Local electronics shops are indispensable when you get a whim to make a curious solution to your particular problem. By the time the parts get to you, you just can&#x27;t help but think how much easier it would have been to just buy something and just feel dumb.

@13a note this “... (2) every single Apple product.” work but not PC and phones. Consistent with the article trying both Android and Linux ... Consistent with image that Apple is in the A&#x2F;V world. Just wonder there are exception e.g. would Sony (a multimedia company) would have the same problem.

The tirade against Apple in the middle article is pretty silly. Android OS has a terrible bug that means you can’t listen to your preferred music on your device. iOS does not have this bug. As someone who uses and develops for both OS, this seems like a no-brainer to me.

One possible solution: get Bluetooth headphones instead, such as the equivalent Bluetooth Audio-Technica headphones to what&#x27;s pictured in the post, the ATH-DSR9BT:<p><a href="https:&#x2F;&#x2F;www.audio-technica.com&#x2F;cms&#x2F;headphones&#x2F;6117c014c965cd1a&#x2F;index.html" rel="nofollow">https:&#x2F;&#x2F;www.audio-technica.com&#x2F;cms&#x2F;headphones&#x2F;6117c014c965cd...</a><p>&quot;The ATH-DSR9BT over-ear wireless headphones employ Audio-Technica’s new Pure Digital Drive system, which allows the headphones to operate without a sound-degrading D&#x2F;A converter that conventional wireless headphones rely upon. Instead, the ATH-DSR9BT utilizes Trigence Semiconductor’s Dnote chipset to receive the digital audio signal from a Bluetooth wireless transmission, process and transfer it to the driver where the digital pulses of the chipset move the voice coil and diaphragm forward and backward to create the sound waves heard by the listener.&quot;

Former audio engineer here. Generally this is the result of high noise floor and poor power management on the amplifier side - not powering down when content isn&#x27;t playing or incorrect power sequencing on the power down of the amp.

There is a lot of satisfaction in understanding and building your own electronics

I have the exact same headphones, and while I don&#x27;t have the &#x27;exploding&#x27; sound when listening on the phone, I do have the constant hissing and it is driving me insane!

All that because the android-media-player-service has a bug.

Two 9V batteries and four op-amps for a low-current output buffer seems like overkill. does anyone know about a better way to go about it?

How the last schematic works ? What is the purpose of 100 ohms resistor and diode in series for ?

Earstudio bluetooth DAC by Radsone would solve all his problems. Check em out they are neat.

The absolute best analog out from a portable audio device that I’ve seen is an iPhone 6.

Are Bluetooth headsets still much behind wired ones in terms of sound quality?

Sounds like all this guy needs is a dragonfly.

Pro tip: There are enough PCB shops now that small designs like this can just be done in free EDA software in minutes, 10 boards in your hand with a stencil 9 real days later for less than $50 shipped. The stencil lets you paste the board all at once, you place parts and hit it with a heat gun until everything sets. For audio stuff you get the advantage of keeping everything nice and tight with lower noise. I barely bread&#x2F;proto board anymore since it is so cheap and easy to get boards made now.

Buy a DAC