
Do I really need to get out the soldering-iron again? - xylon
http://www.naughtycomputer.uk/do_i_really_need_to_get_out_the_soldering_iron_again.html
======
013a
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'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.

I'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't
ship with 3.5mm jacks. If you want lossless audio, you literally can't find
it, even though there's zero reason companies like Spotify couldn'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't even publish physical CDs anymore, so its a game of
luck if they have a website where I can buy the FLACs/ALACs. And if you want
the actual files to, you know, live your life in a completely legal way, those
are gone.

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's oldest technology has
been coopted by companies like Amazon to increase revenue, and there's
practically zero competition. Applications suck; we're puking web and electron
everywhere, eating up every conceivable megabyte of memory available literally
only because developers are lazy, and now you'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/RN.

Somehow we took systems and workflows that were amazing throughout the 90s-00s
and, in the course of a decade, completely ruined them.

~~~
wilsonnb3
Except you’re leaving out all the positives and only focusing on the
negatives.

Sure, Google can revoke my access to a movie at any time but I can watch on
any of my devices and I dont have to worry about finding it in stock at the
local store.

I can carry literally thousands of books with me in a device smaller than a
paperback.

I can’t stream lossless music from Spotify but I can stream high enough
quality that most people can’t tell the difference. Not to mention you get
access to pretty much every song you want for 10$ a month.

Electron apps and the web are replacing desktop apps but they are also making
it easier than ever to make a cross platform app, meaning we will get apps
that we otherwise wouldn’t. This is especially good for Linux, which would be
much further behind macOS and windows without popular electron/web apps
available like slack, Spotify, etc.

~~~
jstarfish
Those aren't positives.

It does nobody any good to have 1000 books on a single device if the whole
thing is subject to revocation, especially when you paid full retail price for
the privilege of being _allowed_ to read it. This is regression.

Previously you paid your $10 and received a paper book. You could read it, re-
read it, lend it, sell it, or burn it for warmth. You owned it for as long as
you kept it dehydrated. The $15 you now pay per book gets you one of these
rights, temporarily.

Whether most people can tell the difference between 320k and lossless is
irrelevant-- the retail price is the same for a technically inferior product.
This is a regression. And again, for your money, you own nothing.

And for apps, the cross-platform compatibility comes at the expense of
consumers, who have to continuously purchase and maintain newer computer
equipment to do the same damn word processing, email and shopping tasks that
used to be possible on a 486. And of course, since everything is a
subscription, it's a double punishment for the consumer-- they have to
maintain hardware to run software they don't own.

The entire premise of modern technology has become a new vector to extract the
most money from the consumer while delivering the least amount of value, power
or control.

~~~
ryanwaggoner
_It does nobody any good to have 1000 books on a single device if the whole
thing is subject to revocation, especially when you paid full retail price for
the privilege of being allowed to read it. This is regression._

What? You can still buy the paperback book, tons of my kindle books are $10 or
less, and it very clearly benefits _me_ , which is why I buy tons of Kindle
books.

~~~
Declanomous
You don't own the book itself though, you own a license to the book. The
doctrine of first sale does not apply, and they can revoke your license at any
time.

They have revoked licenses in the past and deleted books from people's
devices. I know you have a physical file that contains the book, but that file
is secured with DRM.

~~~
bnchrch
> You don't own the book itself though,

To be blunt: Who really cares?

I care that I can read it. After I have I don't see further use for the
ownership.

Others can claim they can revoke my access before the read event occurs but
the chance of that is so low that I imagine it rounds to 0%.

~~~
Declanomous
I mean if I'm only going to read a book once I'm not going to spend $10 on it.
The only books I buy are books I'd like to own so I can read them again in the
future. If I'm paying $10 to read a book once that basically makes Amazon into
a really shitty library that also sells knockoff goods and forces their
employees to work in sweatshop like conditions.

------
notacoward
Interesting point buried in here: since Android is open source, you could go
in and fix the bug, but then because you're not running an official Android
version you'd lose access to the Play Store and other services. Something's
not really free if there'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.

I'm not saying open source is bad and everyone should prefer free software.
It'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.

~~~
ikeboy
You can run the play store just fine on lineageos, which has modifications and
isn't official.

[https://www.google.com/android/uncertified/](https://www.google.com/android/uncertified/)
just need to register here as of earlier this year apparently

~~~
notacoward
Apparently Play Store is unaffected, but some other apps - banking, streaming,
even Pokemon Go - will break. And your warranty (including hardware) is
voided. So I stand corrected, and thank you, but I don't think the correction
affects the main point.

~~~
ikeboy
Those apps are making a conscious decision to exclude phones/roms not
certified by Google. That's their choice.

Generally hardware warranty will remain if it's purely a hardware issue - you
can always flash back anyway.

Android is free software in the sense that you can make and distribute
modified versions. If app vendors choose to discriminate against those
versions that doesn't make it unfree any more than software supporting windows
and not Linux makes Linux unfree

~~~
notacoward
> Android is free software in the sense that you can make and distribute
> modified versions.

I don't think that's enough to make it free software, and "free software in
the sense..." is nonsensical. Free software would _guarantee the continuance_
of that freedom. Since that guarantee doesn't exist, Google could place
limitations on the Play Store at any time. The fact that they haven't makes
the example less clear, but it doesn't make Android free software. Even Google
doesn't claim that it is.

~~~
ikeboy
Play store isn't part of Android. Even if it was only available to specific
phones, that wouldn't make Android unfree.

Play store isn't open source at all.

Amazon was able to take Android and put it on their extremely popular devices
with 0 support from Google, no play store. That's what I call freedom

~~~
SSLy
Play store isn't part of AOSP.

------
baxtr
_> Right now I'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't even listen to a fuck-damn music track? O_o_

I enjoyed reading this. The whole time I thought however: that’s not an issue
on my Apple devices. Then I read:

 _> If anyone reads this post I'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._

Well, at least it usually simply works.

~~~
ignoreInstinct
Yeah, but what really gets under my skin is that every other company out there
is okay with producing garbage.

Meanwhile, Apple produces things that work comparatively well, doing _what you
expect_ and then, claims that reasonable functionality is _premium_. And then
catches shit for being pretentious.

So, let's step through that once more:

    
    
      - garbage is normal
      - functional and interoperable is premium
      - premium is pretentious
      - also, add $1,000 for the name brand
    

The author simultaneously complains that nothing works, but refutes using the
only thing that works because it represents training wheels that are too
fashionable and ostentatious.

We can have nice things because that's for babies, and also too overtly
glamorous and bougie.

I just want shit that works out of the box sometimes. I also don't need
X-Files alien logos and red backlit Hunt For Red October themes everywhere.
And oh yeah, let's not get started on OEM spyware masquerading as harmless
adware. ( _Cough! Lenovo! [0] Cough! Intel Management Engine! [1] Cough!_ )

[0] [https://forums.lenovo.com/t5/Security-Malware/Malware-
preloa...](https://forums.lenovo.com/t5/Security-Malware/Malware-preloaded-on-
new-computers/td-p/3876408)

[1]
[https://en.wikipedia.org/wiki/Intel_Management_Engine#Securi...](https://en.wikipedia.org/wiki/Intel_Management_Engine#Security_vulnerabilities)

Will someone other than Apple please step up to the fucking plate and not just
dump trash onto the shelves at Best Buy?

~~~
thanatropism
The Apple premium has gone so damn high though.

I got my first Mac when the Mac mini came up. It was a little more expensive
than same-generation PCs but besides being OSX it was a PowerPC that never
made any fan noise, and was _small_. I've subsequently had three Macbooks and
two iPhones - but I can't afford this somewhat-better-somewhat-more-expensive
racket anymore. Prices have risen too much; to boot, the quality gulf between
Macs and garden-variety Dells and Acers has pretty much crashed. Macbooks have
had multiple problematic years now; iPhones did away with headphone jacks; and
OSX peaked at 10.6.8, where it indeed was five years into the future - but
Windows 10 is decent now and even has the whole Unix toolkit with WSL.

~~~
pdimitar
Disclaimer: not trying to convince you, just sharing an anecdote like you did.

\- I agree Apple pricing has gone out of control. I should not have to shell
out 1500 EUR for a 256GB phone with a bigger display no matter what (XS Max).
I mean okay, it's probably the best phone out there but come on. It's a mobile
computing device, not a life's insurance bill.

\- I fully agree MacBooks and desktop Macs haven't had good years in a while.
IMO the MacBook Pro 2015 15" was Apple's laptop peak. They haven't produced
anything worthwhile in the laptop departments ever since.

\- Desktop Macs are a horrid mess where greed trumps everything else so much
that even I who spent 6 figures on tech during my life cannot justify paying
5000 EUR for an iMac 27" 5K with maxed out specs (i7 CPU, 64GB RAM and 1 or
2TB SSD). Right now your only viable choice for a future-proof machine however
is either the iMac 27" or the iMac Pro, and both are expensive as hell.

\- macOS version, not sure, I started actively using it only a year or so ago
so it feels quite good to me and is tons more predictable than Windows 10. You
have to fight with Windows 10 to make it your own and not be barraged with
popups. macOS in comparison stays out of the way.

\---

To summarize, Apple has peaked, including in the smartphone and tablet
departments. Upgrades are very smallish and iterative while the price tags
remain huge.

The way I see it, Apple has been coasting for a while. They need to get back
on track because inevitably somebody will try and displace them.

(As a random example, Xiaomi phones are probably the best physical designs and
software experience I ever had. But I still don't trust Google's binary blobs
and the general baseband processor stuff so I stay away from Android.)

~~~
andrepd
>But I still don't trust Google's binary blobs and the general baseband
processor stuff so I stay away from Android.

Why do you trust the Apple ones then? At least on android you can get rid of
most Google code with Lineage + microg

~~~
pdimitar
> _At least on android you can get rid of most Google code with Lineage +
> microg_

...as far as we know. What about the baseband processor that has access to
everything at any time?

> _Why do you trust the Apple ones then?_

Becase they took a stand and refused to introduce a security backdoor in the
FBI San Bernardino case. And because iPhone hacks cost more on the net
compared to Android ones. This to me indicates that iPhones are harder to
crack -- so the demand is higher, suppy is lower and thus the prices are
higher.

All circumstantial evidence of course, but it's what we have to go on.

~~~
mirkules
Also, compare OS updates: Android has significantly more critical security
fixes than iOS, every single time.

Maybe it means they are finding more bugs and fixing them, or maybe it means
Android is basically security Swiss cheese. my money is on the latter.

~~~
handzbagz
Android has a hell of a lot more people developing it/for it. I wouldn't be so
sure of that assumption.

~~~
pdimitar
That doesn't mean much when flashing their ROM means voiding your warranty
though. Also, their efforts don't really count in the very important areas
like the OS security itself; Google reigns supreme there, mostly.

I am a former flashing-ROMs fanboy but the truth is, you are either stuck on
ancient kernels or sometimes part with functionality you prefer to still have
(like rooting).

I gave up, eventually.

------
dextersgenius
> _It turns out that all music players on Android actually play music using
> the Android-media-player-service._

This is inaccurate. Neutron music player bypasses Android'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'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.

~~~
shittyadmin
I've never had any problems with "explosions" using standard media players,
even when plugged into my HD650s - anyone else have that happen?

HN is mostly engineering types, the poster clearly has that mindset, we should
be filing or looking for a proper bug report for this instead of crafting
hacks or talking about alternative products altogether right off the bat.

~~~
amelius
> we should be filing or looking for a proper bug report for this instead of
> crafting hacks or talking about alternative products altogether right off
> the bat

As if Google even considers reading any bug reports ... :(

~~~
kerneis
Googlers read HN though ;-)

(source: I work for Google)

~~~
vvillena
That explains why the best way to reach the bigger tech companies is to make a
complain go viral here. It's kinda fucked up.

------
mindslight
IMHO your circuit topology looks wacky. Perhaps there'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 -

You'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.

How purposeful is that whole low side duplicated circuit and why? [0] It seems
like since you'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.

Isn't there a vibrant cottage industry of external USB DACs and headphone
amplifiers and whatnot? I'm more of a receiver+speakers type of a person, but
I often see newly designed stuff for headphones.

[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't actually do that lest you get crosstalk in the
form of clipping, I don't think this is your goal!

~~~
jacquesm
I think the trick here is that the resistors are much more precise than two
batteries of unknown origin will be at providing a symmetric supply voltage
without further stabilization. So they serve as a 50/50 voltage divider
_whatever_ the input voltage is, 7+9 or 6+8 on half full (or half empty,
depending on your mental make-up) batteries, it would still work just fine.

Binding the central line between the two 9V batteries to GND would give you
the situation you describe, indeed you could then drop the resistors but now
you have a fairly high risk of ending up with an asymmetric supply voltage,
which means one side will clip earlier than the other.

~~~
mindslight
Is this really a common thing? I don't really have experience with battery
powered audio processing circuits. In my experience you usually create a
virtual ground when you've got no other choice, like say signal conditioning
with a single ended supply.

~~~
jacquesm
Yes, in battery powered stuff it is pretty common. When working from a single
supply it is a quick and easy way to use operational amplifiers.

That the author used two batteries in series did not change much in that
respect (and internally those 9V batteries are a stack of 6 cells anyway). The
alternative would be to use the common rail between the two batteries as a
ground and then two regulators (or simply a Zener and a follower transistor,
same effect for less cost) to get say plus and minus 7 or 8 volts depending on
how far you want to run the batteries down and what kind of specs that op-amp
has.

Most op-amp circuitry would be +- 15V, but they usually work on much less than
that. The circuit as presented here probably has a DC bias that is in the
100's of mV, there is no adjustment for it either so it is a bit of a kludge
the way it is set up. There are better ways to do this, it all comes down to
part variation and that should not be a factor in a good schematic.

There are single supply op-amps too, but in this case I suspect the voltage
required to drive those headphones properly was the major deciding factor in
using two stacked 9V cells.

~~~
mindslight
> _But in this case I suspect the voltage required to drive those headphones
> properly was the major deciding factor in using two stacked 9V cells_

Maybe it was the deciding factor for whomever designed the original circuit.
But in this incarnation with the 11x attenuation, the input signal would have
to be above 80V for this to matter! It's obviously modified from some folk
audio design, I'm just trying to figure out how much of its oddity actually
has some purpose.

~~~
jacquesm
Yes, it definitely looks like a 'stacked hack', not something that was
designed with purpose by someone who really knew what they were doing. No
mention of distortion, no bias adjust, DC coupled (could be good, could be
really bad depending on the bias...).

There are some pretty good headphone amplifier circuits out there, most of
them a little bit more complex than this but with what I would expect to be
far superior specs.

------
edoo
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/proto board anymore since it is so
cheap and easy to get boards made now.

~~~
mgalgs
I used to use BatchPCB and LOVED the service. When Sparkfun shut it down I
couldn't find any decent alternatives and pretty much just quit making boards.

It looks like Osh Park has a pretty decent offering these days, but I'm
curious who you're using with 9 day turnaround time? That's amazing!

~~~
weaksauce
I ordered some from jlpcb on a Monday and by Friday they were here. Express
shipping brought it to $19 shipped for 10 boards. I’m sure most places like
that are similar in lead times.

------
gcp123
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.

~~~
bhj
It’s amusing to still hear “Apple tax” in 2018, as if there is no additional
value in better hardware, software and support for many people’s use cases.

~~~
yaseer
If anything, the 'Apple tax' is greater in 2018 than it has ever been.

I say this as having owned 3 Macs for the last 10 years. 4-8 years ago, the
gap between Apple and the rest was so stark, it seemed paying for a premium
Apple product was a no-brainer.

Even Linus got a Macbook air because the hardware was such a leap ahead.

Not only has the gap closed, Apple have been left behind, with inferior build
quality in key areas (keyboards). This has coincided with raising prices
further.

The 'Apple tax' is now a real phenomenon, not just the price of premium.

~~~
lern_too_spel
Linus hasn't used a MacBook Air for several years now. Apple's devices are now
inferior in every category.

------
alkonaut
> YOU DO NOT EVEN KNOW HOW YOUR PHONE WORKS

I know it _does_ work.

Would I prefer to have a more open phone and computer? Sure. At the cost of
having to ever tinker with it? No.

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.

------
rayrrr
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're serious enough about
photography, you don't complain about your smartphone camera's limitations,
you get yourself a DSLR and multiple lenses. So if you'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't been this happy since the early
aughts.

~~~
Johnny555
_why not get a dedicated device?_

For the same reason I don't want to carry a big heavy DSLR around with me,
because there's a limited number of devices I want to lug around.

I ditched the DSLR years ago (yes, it took great photos, but not enough to
make it worth the hassle). Though I still bring a pocket sized camera with me
when I travel because my smartphone still can't compete with a big sensor and
an optical zoom.

While a dedicated MP3 player is small (to be honest, I didn't even know they
were still made), it's just one more thing to keep track of and keep charged
up.

~~~
PascLeRasc
It doesn't have to be a whole separate device. The Audioquest Dragonfly is the
size of a USB stick, runs off your phone's power, and provides excellent
DAC/amp capabilities. Fiio also makes some similar mobile DAC/amps.

Here's a nice long article on the details:
[https://www.computeraudiophile.com/ca/bits-and-bytes/an-
audi...](https://www.computeraudiophile.com/ca/bits-and-bytes/an-audiophile-
switches-from-ios-to-android/)

------
flocial
I'm a bit flabbergasted by all the "wow this person just wasted all his free
time fixing a nonexistent problem instead of just getting an iPhone" on Hacker
News of all places. Yes there's an ideological bent to the whole exercise but
that's precisely the kind of passion you need to deep dive into creating your
own audio device over a minor annoyance. Yes it'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'm
sure a good mental jog for the author.

~~~
ummonk
If he had just said "I want a phone I can tinker with, so the iPhone doesn't
fit the bill", no one would object. The problem is his claim that Apple is a
symbol of pretentiousness and ignorance, simply because it provides
convenience and out-of-the-box usability without needing to know how it works.
Most people don't tinker for a living / hobby, and thus don't have the luxury
of spending large amounts of their valuable time figuring out how the device
works and tinkering with it.

Not understanding this actually a sign of pretentiousness and ignorance.

~~~
flocial
Thank you and others for pointing that out. I can see how a blanket insult
that would unintentionally fit many Hacker News users would lead to a pile on.
I've been on an iPhone forever but I've stopped considering it and Apple part
of my identity. It was such an extreme statement in an otherwise interesting
article that I took it as humor to be honest.

------
pdimitar
I'll allow myself some generalization here.

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.

In that regard, they are hard-working and resourceful. And I have a lot of
respect for them.

That being said, I cannot help but notice things common among all of those
that I know or used to know:

\- Apple hate without any regard for the advantages it gives you.

\- 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't know if their relationship wasn't
sour before but still, it's partially indicative.

\- Obliviousness how Android is not the end-all-be-all of free software --
because it'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.

\- Complete disregard for convenience and utter lack of respect for others'
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.

\---

I am somewhat saddened to say the OP's article confirms my bias towards
hardware technicians. He's undoubtedly smart and good at what he does but also
heavily biased and lacks perspective.

I believe such resourceful people should be more open-minded. If he'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.

~~~
shaan7
Hate doesn't work, I'll give you that. I'm hopeful that OP takes your feedback
:)

But you're very mistaken about the "disregard for convenience". Almost every
human strives for convenience, even the folks you are talking about, they
spend a lot of time writing automation scripts to make their work convenient.
Just like you advice, please be open-minded to the idea that for some people
convenience is just one checkbox on the list (unlike others, maybe including
you, where convenience is of prime importance). For some people, real
convenience comes from both functional convenience and tinkerability - having
the confidence that they can make the product what _they_ want to do - without
feeling limited by the manufacturer's decisions. At the end its about
tradeoffs, and when it comes to personal choice, people simply have different
priorities.

To give you an objective example, when I buy a router, I always first go for
an Asus. Why? Their UI is super easy to use - and at the same time, if you
want, you can get it do to more powerful stuff. Just like Apple (as folks
claim), their support is great (I've got replacements, no questions asked)
but, unlike Apple, they actually encourage you to tinker around. So in this
case, hell yeah, I do pay the extra premium for convenience.

~~~
pdimitar
> _Just like you advice, please be open-minded to the idea that for some
> people convenience is just one checkbox on the list_

Noted, agreed and upvoted. :)

From my experience with these folks, when I complained about the 1st gen
Chromecast I had 3 or so years ago, one of them casually told me "Oh, just buy
an RPi and install KODI on it, also make sure your TV and HDMI cable support
HDMI-CEC. You should be sorted pretty quickly, probably three or four hours".

I had to laugh bitterly when he said that! Back then I was much less healthy
compared to now, was constantly exhausted, was struggling with debts and
crappy jobs, was trying to heal from a failed and ended marriage -- and in
general I had a ton on my plate basically 24/7.

And along comes this guy and casually tells you that you might spend a half
working day on a project for home streaming -- and he told it to me while
full-well knowing my situation. It was pretty inconsiderate in my eyes.

\---

It's not even only about putting convenience at the top of your priorities.
Sometimes you're just tired. Or have kids constantly demanding attention. Or
are trying to heal from stress and burn out (like I am trying now). There are
a plethora of VALID reasons why you wouldn't embark on such DIY projects.

And to me, these people easily and off-handedly dismiss them. Which I view as
inconsiderate and disrespectful. They are judging things from their own life
(which is easier than mine, at least regarding the people I know) and don't
give the benefit of the doubt.

But I concende that I might be projecting based on my several such negative
experiences. I am not stereotyping all hardware technicians and sysadmins. I
also concede that I don't give benefit of the doubt every time. :)

It's just that when things repeat themselves several times, we the humans --
at least I -- tend to try and draw a conclusion.

I admit I could be wrong. Your perspective was appreciated!

~~~
mgalgs
You're not wrong, but just remember that there are people in this world
looking at you and all of us "nerdy engineers" exactly the same way.

Not that we need to stress about that, I mean we _all_ look like douchebags to
_somebody_. I just think you might be jumping the gun with character
judgements such as them not respecting your free time. The guy who told you to
spend 3 hours tinkering with your Chromecast would probably love working on
that project himself, and assumed you might enjoy it too. He might have been
trying to help you take your mind off of the stresses he know you were dealing
with.

------
projektfu
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't experienced
it but I also do not use this writer's particular sound files.

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'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't appear to want to make a product that plays a clear sound.

As far as circuits are concerned, I can'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.

~~~
jjoonathan
They are not shaving BOM pennies, they are shaving NRE pennies. The components
to produce good audio are dirt cheap, even for a consumer product, even in
quantity. Keeping digital noise out of analog circuits, however, takes effort.
Getting the software to not drop step functions at inopportune moments takes
even more effort. They won't do these things unless they feel they have to.

~~~
tomcam
NRE == Non-recurring engineering costs, in other words, stuff like R&D. This
was my first encounter with that term.

------
praptak
”It improves sound quality by taking away the hard work of driving the dynamic
load of the headphones from the device"

Can anybody explain that please? What is this dynamic load whose driving is
hard?

~~~
LeonM
Converting an electric signal into mechanical movement takes energy. Thus,
current needs to flow from the audio amplifier in the CD player to the
headphones. In electronic terms: the headphones have a low impedance (AC
resistance).

Due to a poorly designed circuit in the CD player, noise is introduced when
current flows. So the more current is flowing, the more noise. Driving a
dynamic load is not hard, it has been solved for a long time. The vendor just
chose a poor design, probably to shave a couple tenths of a cent from the
material bill.

A proper designed amplifier requires very little current (ideally none) on the
input. In electronic terms: the amplifier has a high impedance. Thus the
amplifier causes very little noise when connected to the cheap CD player.

The OP build a better amplifier that causes less noise when current is drawn
from it, so using that results in a better quality sound.

~~~
praptak
> Due to a poorly designed circuit in the CD player, noise is introduced when
> current flows.

Thanks! This was the missing part.

------
dejaime
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...

~~~
JshWright
If it ain't broke... fix it until it is...

------
nycticorax
A USB DAC+amp seems like the right answer if you _don 't_ want to break out
the soldering iron and don't want to buy an Apple product. I just don't think
makers of commodity hardware have much incentive to spend money on good audio
circuitry. But if their USB ports didn't work, well, that would be a real
problem. I have an earlier model of this:

[http://www.schiit.com/products/fulla-1](http://www.schiit.com/products/fulla-1)

that delivers good audio quality (to my non-audiophile ears). The one I have
is not perfect: there's some static when you turn the volume knob (maybe a
good design tradeoff at the price, I don'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't
any background hissing like there is with the built-in headphone jack on my
Dell workstation.

------
squarefoot
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.
[https://www.thomann.de/gb/miditech_audiolink_light.htm](https://www.thomann.de/gb/miditech_audiolink_light.htm)

About the article circuit, I 'm not that sure the 5532 is a good part for
headphone amps, unless the phones have a high impedance and resistance:
they'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:)

~~~
MegaDeKay
Regarding the op amp selection, he just used them because he had them lying
around.

    
    
      "If you wanted best possible sound you'd use some actual audio op-amps rather than these cheap NE5532P. And buffer the output of the op-amps somehow. But of-course size and cost balloons if you start adding buffers and stuff."
    

What I like about his project how he simply used a couple magnets to hold the
lid on. Microsoft did something similar on my keyboard, but I don't know that
it is something used much on DIY projects like this.

------
ricardobeat
Could’ve spent $199 on an iPod, have high quality audio, load your own music,
no “apple tax”.

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.

~~~
DanBC
> I was looking for something like an ipod shuffle this week and it’s become
> almost impossible to find,

What's wrong with the Sandisk products?

EG Clip Jam: [https://www.amazon.co.uk/SanDisk-Clip-Jam-
MP3-Player/dp/B00V...](https://www.amazon.co.uk/SanDisk-Clip-Jam-
MP3-Player/dp/B00VXMY262)

~~~
jaifraic
Ah, I miss my good ol' Sandisk Sansa Clip+. This device with rockbox firmware
and a MicroSD-Card had an amazing interface, enough storage for lots of music,
supporting FLAC and other lossless formats, all while being small, lightweight
and providing high audio quality. For about 40 bucks.

~~~
DanBC
Sadly, I think some of the newer devices can't take Rockbox. I think the Clip
Jam can't.

------
hunta2097
Have had 8 android phones.

Literally never heard anything like this.

~~~
creeble
Me either.

My last three Android phones (two Motorola and an HTC) have excellent sound
from their headphone jacks. I use my phone and two iPads on a regular basis
with headphones, and I've never heard pops between tracks or noticeable hiss
with any of them.I

I write audio software on embedded Linux devices for a living. I know what
clicks and pops between tracks sound like, and usually why they happen. But I
don't think this guy's two-op-amo buffer is doing what he thinks it's doing.

------
Sidnicious
I'm super curious…

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).

b. Whether an output attenuator (or "resistor") would work to quiet the noise
(edit: the hiss, not the explosion) without a powered circuit.

~~~
xylon
Hi, author here, I can't send you a sample because of copyright but get "scare
force one" by Lordi on CD and rip it into any format.

~~~
PascLeRasc
Hi, this isn't related to the parent comment, but I'm wondering why you went
through all this effort, which you don't seem to have enjoyed, just to be able
to listen to music at home but not at your desk. Isn't all the stuff you have
pretty bulky to be carrying around? Not to mention the portable CD player
probably skips if you're walking around with it somehow in a pocket.

It seems like all of this could be solved with some bookshelf speakers. You
can hook up your portable CD player or browse Craigslist/Goodwill for an older
HDCD player that'll run higher sampling rates and queue up multiple CDs, have
music for cooking/cleaning/exercising. Maybe even get a Chromecast Audio and
have effortless streaming.

------
korethr
If he's able to get that much of an improvement with 5532s, I'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.

The circuit design looks weird to me. Wouldn'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'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?

1\. [https://nwavguy.blogspot.com/2011/08/op-amp-
measurements.htm...](https://nwavguy.blogspot.com/2011/08/op-amp-
measurements.html)

~~~
madengr
Maybe he’d be better off just using a transformer. Don’t these high end
headphones have a high impedance?

~~~
korethr
Depends on the headphones. Some have higher impedances, some have lower ones.
Transformers bring their own complexities into the circuit.

------
Johnny555
_I DO NOT HAVE TO PAY A TAX TO APPLE TO LISTEN TO MY MUSIC._

Is it better to pay a tax to Google and not be able to listen to your music?

(I say that as an Android user who hasn't run into this problem, though 90% of
my listening is through streaming services, I still have all of my CD's
sitting on a hard drive, but they are all (as far as I know) available over
streaming now, so I just use that)

------
aetherspawn
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.

~~~
_trampeltier
I bought a Bluetooth speaker a couple of months ago. Sounds great, but if I
watch a video, the sound is lagging. I thought about to get Bluetooth
headphones, but after that experience I think, I just stay with cables.

~~~
Renaud
Explanation of why there is lag when watching video and listening over
Bluetooth and how it is taken care of:

[https://www.youtube.com/watch?v=eYW4J6FyyZU](https://www.youtube.com/watch?v=eYW4J6FyyZU)

To ensure (kind of) that your BT speaker/headphones will be able to work with
video, check they implement "AptX low latency".

However, as they mention in the video, there are lots of ways this could fail:
application playback issue, BT transmitter issue (although anything from the
last few years should be able to handle this properly) or receiver issue (the
most likely cause in older or cheap speakers).

------
temp0876456
Boy does this person need to look at the ‘good headphone’ market.

I paid (a very reasonable) $2k for a set of reference headphones and a
suitable amp/DAC to drive them.

I could have spent a lot more.

It _is_ hard to drive a set of headphones with enough SQ to make them
worthwhile.

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...).

Getting good sound from a portable device, without software issues, is really
only solved at the top end of the market ($700 - $4000).

It’s a bit easier if you want to use a computer as a source but far from
cheap.

~~~
ikeboy
Is it just me, or are $10 branded earbuds just fine for music?

~~~
dsego
Did you try any more expensive ones? If not, how can you compare? I don't
think you know what you're missing. From my experience, you realize how bad
cheap ones are is when you try something better. For example, I thought AKG
Y20 sounded pretty good before getting the chinese TFZ series 2, which are
just so much 'more'. I am aware that those tfz are also lower range (~45$ on
aliexpress). I also own a pair of Beyer DT770 80ohm 100 eur headphones and
those are something else, esp when I had a Focusrite Saffire to drive them. Of
course there is a price point after which it gets harder to notice
improvement. But only after trying out different types and price points do you
start to understand what sounds good and what you actually like. For me, all
cheaper ones just sound muddy or like the sound is trapped in some box or tin,
and I also notice sounds and instruments missing in songs I know well.

~~~
ikeboy
If I'll enjoy my current ones less after trying more expensive ones, isn't
that a reason not to try them?

I do see a difference between the branded ones I've used (mostly Panasonic and
the Samsung AKG one that comes with phones) and the cheaper generic ones I've
tried out here and there

~~~
dsego
For example, I couldn't tell the difference between some ~100$ and "reference"
~1000$ headphones, so I am not the person to buy high end DACs, fancy shielded
cables or whatnot. But I like some thumping bass and clarity in the top end.
It's therapeutic for me to have an immersive experience where the sound just
floats around you, sort of 3d vs flat.

------
AdmiralAsshat
Can't say I've ever had the explodey sound any of my Android phones through
the audio jack. I've had it a handful of times with some bluetooth buds, but
I'd just as soon chalk it up to their cheapness.

I _do_ have the hissing sound he's described when using my ATH-M50's with my
phone, and even my laptop. My solution (albeit more expensive than his DIY
one) was to buy a portable DAC/amp, specifically a Fiio E17[0]. It connects
via USB/micro/C, and it's worked on every laptop and Android phone I'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's that are not too expensive. It'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's the price of fidelity.

[0][https://www.amazon.com/FiiO-Alpen-Portable-Headphone-
Amplifi...](https://www.amazon.com/FiiO-Alpen-Portable-Headphone-
Amplifier/dp/B0070UFMOW/) [1][https://www.amazon.com/FiiO-Desktop-Headphone-
Amplifier-Dock...](https://www.amazon.com/FiiO-Desktop-Headphone-Amplifier-
Dock/dp/B004M172FY/)

------
kazinator
> _Battery life is only a few hours unfortunately because the circuit draws an
> enormous idle current of 23mA :o_

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!

Secondly, the device contains a bizarre circuit that tries to amplify the GND-
GND path, using two op-amps in parallel.

The numbers check out: 9 mA for the voltage divider, plus around 8 mA x 2 IC-s
(typical value from datasheet): 25 mA.

Here is how we can fix things.

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.

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.

We're now down to the current draw for a single NE5532.

3\. Use a different op-amp. The NE5532 isn't great for driving low impedances
like headphones. There are op-amps that are better suited for this, _and_ draw
less quiescent current.

------
johncolton
For < $100, I got a USB device which is a DAC+PreAmp+HeadphoneAmp which works
great with all Androids, iPhones and computers. I didn't have to solder or
breadboard.

------
twtw
Can anyone comment on what's going on with the ground channel in the circuit
here?

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't do that - it just replicates the L/R chains twice between grounds.

Also, what'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?

~~~
s800
Doesn't make any sense to me either. He's burning 2ma for no reason.

------
dijit
> I do not have to pay a tax to apple to listen to my music.

Well, neither do I to be fair. I seriously dislike iTunes but it can take more
input than just the store..

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)

~~~
chrismeller
I think his point was less about the purchasing ecosystem for the music and
more about the premium for the hardware/OS/brand/accessories/what-have-you
required to play any music at all.

Though, seriously, if I can throw a little bit extra (shockingly not a lot,
compared to similar modern Android offerings) at my phone and not have this
kind of basic problem and, presumably, other basic problems of a similar
nature then there is a tipping point of efficiency that isn’t terribly far
away.

------
makecheck
I saw similar problems _creating_ music and sounds: having “good” audio
hardware means that _every sound flaw you have is now obvious and annoying_. I
had to be much more careful. Frankly, good sound production and programming
are both underrated, they are not trivial.

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

------
amelius
Why does it use two opamps for the ground signal?

~~~
ThePhysicist
Since you have two channels that source current (L and R) it makes sense to
have two parallel op-amps for the GND pin to have the same slew rate & maximum
current, as both L and R channels return current through the GND line (I would
assume).

~~~
mannykannot
I am curious as to why it needs any circuitry on the ground line - would a
direct connection not work? (I guess I am assuming that L, R and ground are
the only connections made to the headphones.) Do the amplifiers put a DC bias
on the L and R outputs that needs to be matched on the ground, and if so,
would a capacitor in series with the L and R outputs not be enough to isolate
it?

~~~
megous
You could just use the middle connection between the two batteries as a
ground. I'm not sure why he didn't do it. Perhaps so that the whole thing
works longer even if one of the batteries is discharged faster. That would be
my guess.

~~~
mannykannot
As it stands, 40% of its 23mA current draw is through the 1kΩ x 2 voltage
divider... Now I am wondering if a circuit with the between-battery link
connected to ground would risk damaging the op amps (or phones) if only one
battery was in?

------
IshKebab
I'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're using sensitive headphones on low volume.

I actually bought Google'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't
robust enough - if you wiggle it around as if it were in your pocket you
easily get glitches.

------
justin66
Odd that the author poses this question:

 _Maybe it doesn 't like the metadata in those tracks?_

and doesn't go on to discover the answer. If my ripping and encoding routine
were doing something funky that causes problems I'd really want to know about
it, and it wouldn't require me to debug Android as the author implies.

It's true enough that Android playback probably shouldn't be glitching, but if
the track metadata is invalid or pushing the limits of what you can do,
whatever he's doing to his tracks is likely to cause problems in places other
than Android playback...

------
mhh__
With all "high quality" audio matters like this - and compressed music - I
genuinely don'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.

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.

~~~
clarry
I have several musical instruments and a bunch of relatively high end audio
gear.

The point of dimnishing returns starts at $0, what matters is what kind of
quality you want. Every once in a while, I buy some headphones in the <$100
range but I generally turn away in disgust because the sound just isn't good
to my ears.

This summer, I had to buy a new phone, I went for a OnePlus 6. I figured I
could use another pair of IEMs/earbuds so I bought the kit they offered with
the phone. Tried them once, for about ten minutes, and threw them away. Yuck.
These are obviously $2 kit of garbage sold at a massive premium..

------
setquk
Just buy an iPhone.

Oh no wait. No hole that decent headphones fit in.

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.

~~~
samatman
Suggestion if you haven't: take a plastic dental pick and try to get lint out
of the headphone jack.

I've had to do this sooner or later to every phone I've owned, except my
latest, which lacks this port entirely.

~~~
setquk
Yeah I’ve done that. No luck. I’ve used switch cleaner on swabs as well. Think
it needs a new port. However I can’t be bothered to take it to Apple store
yet.

------
patchtopic
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'm missing here?

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

------
alexkavon
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/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.

------
solemsigne
> Shame Maplin closed because now I have to order parts off the internet and
> WAIT.

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't help but think how much easier it would have been to just buy
something and just feel dumb.

------
kwccoin
@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/V world. Just wonder there are
exception e.g. would Sony (a multimedia company) would have the same problem.

------
iOSGuy
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.

------
bascule
One possible solution: get Bluetooth headphones instead, such as the
equivalent Bluetooth Audio-Technica headphones to what's pictured in the post,
the ATH-DSR9BT:

[https://www.audio-
technica.com/cms/headphones/6117c014c965cd...](https://www.audio-
technica.com/cms/headphones/6117c014c965cd1a/index.html)

"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/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."

------
Azerb
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't playing or incorrect power sequencing on the power down of the
amp.

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

------
Vanayad
I have the exact same headphones, and while I don't have the 'exploding' sound
when listening on the phone, I do have the constant hissing and it is driving
me insane!

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

~~~
TeMPOraL
You can't really replace android-media-player-service on your phone with your
patched version without replacing the whole OS and losing (among other things)
automated security updates and OEM stuff... so I can see how a hardware fix is
easier. The system of <phone> \-- <headphones> is more modular.

~~~
icebraining
You probably can, by rooting and making an Xposed module. But yeah, the amp is
more generally useful.

------
duck2
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?

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

~~~
megous
To discharge the capacitor when he turns the thing off in a controlled
fashion?

Otherwise the current will slowly leak through the zener diode and the 100kohm
resitor and the capacitor will stay charged. So when he turns the thing on the
next time it would not do the expected timed battery charge indication he
wants.

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

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

------
sasaf5
Are Bluetooth headsets still much behind wired ones in terms of sound quality?

~~~
vardump
As an owner of Bose QC35... yes.

The headphones themselves sound pretty good. But when playing over bluetooth
sometimes compression artefacts are audible. The artefacts are caused by the
bluetooth protocol for stereo audio itself, so you're going to hear them even
if you play FLAC files.

Also latency is pretty horrible. 200 ms+, enough to be obvious.

~~~
rvense
I think those are what I have at work. I'm quite sure they do a bunch of stuff
of DSP/EQing to make them sound better than they are. When you turn the power
off and use them as normal headphones they're mediocre at best.

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chemmail
Sounds like all this guy needs is a dragonfly.

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g5095
Buy a DAC

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Trombone12
Were would that go? The author doesn't seem too keen on actually soldering on
the inside of the devices, and they all give analogue out. Maybe you meant an
amp?

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Jaruzel
A USB DAC connected to the old-laptop maybe? I have one on a Mini-PC that's
the player for my music library - totally moved the digital-to-analogue
conversion out of the noisy PC, and results in really clean audio. Obviously
you get what you pay for - a £20 DAC wont do a very good job, but a £100 one
will be good enough for most people.

