Do I really need to get out the soldering-iron again? • Hacker News Board

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

#311

Post by baroffoos » Sun, Dec 09, 2018, 10:33 PM UTC

acabal wrote: post #213

013a wrote: post #156

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 p…

Re. flac downloads, Bandcamp (almost?) always offers a flac download option. You'd be surprised how many bands have a Bandcamp page, even if they're signed to labels. The option is not well advertised. After you purchase a digital download, there's a tiny arrow next to the 'download' link that allows you to switch the download to flac. I always download flac and consequently spend a lot of money at Bandcamp!

Bandcamp is pretty much single-handedly keeping high quality audio alive. I exclusively buy music from them and then load it on to my own music streaming server.

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

#312

Post by baroffoos » Sun, Dec 09, 2018, 10:35 PM UTC

anotheryou wrote: post #201

013a wrote: post #156

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 p…

Did you do a blind test on spotify's high quality vs lossless? At least with 320mp3s I could only get it right with certain songs and not too consistently. I'd say my room treatment has a far bigger impact. (but regarding hardware I'm totally with you and haven't found the source of my rather high noise floor either)

FLAC is best for archiving songs. MP3 is outdated tech and if I wanted lossy audio I would use opus but transcoding MP3 to opus will destroy the quality of the track so you have to go FLAC -> opus

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

#313

Post by codyb » Sun, Dec 09, 2018, 10:41 PM UTC

admax88q wrote: post #309

013a wrote: post #156

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 p…

> 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…

They also list products that don't do it, so seems like it wouldn't be that.

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

#314

Post by mindslight » Sun, Dec 09, 2018, 10:42 PM UTC

jacquesm wrote: post #276

mindslight wrote: post #215

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 wh…

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 batte…

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.

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

#315

Post by 013a » Sun, Dec 09, 2018, 10:53 PM UTC

admax88q wrote: post #309

013a wrote: post #156

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 p…

> 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…

Mackie MR5s are studio monitors, not headphones.

I can plug them into an analog output device and they work perfectly. I'm talking about digital, and the only digital devices that work are a Vizio TV (possibly others, didn't really test against TVs), iPhones, iPads, and Macs.

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

#316

Post by Siilwyn » Sun, Dec 09, 2018, 10:57 PM UTC

shittyadmin wrote: post #100

dextersgenius wrote: post #35

> _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 6…

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.

I've actually had this a couple of times on my Android 7 phone listening with earbuds or headphones. It seems to happen randomly.

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

#317

Post by 013a » Sun, Dec 09, 2018, 11:00 PM UTC

andthat wrote: post #217

013a wrote: post #156

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 p…

You tried balanced cables?

Yup; the speakers support both unbalanced RCA and balanced XLR. Same issue on both.

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

#318

Post by nathan_f77 » Sun, Dec 09, 2018, 11:03 PM UTC

mlindner wrote: post #284

alanpage wrote: post #242

Earlier quoted context omitted.

Test your system (and your room) with this audio quality quiz, comparing lossless audio with several compressed bit rate streams [1]. With my 50-year old ears, and an outboard DAC/amp and audiophile magnetic planar headphones, I could only score 50%. That said, switching between Spotify and Tidal on the same track, I hear a pretty big difference. The lossless music has a depth that just isn't there on the compressed…

I think some of it is whether you're used to listening to the type of music. All those samples are types of music I don't normally listen to and thus scored 0%. They're also mostly low-information songs that are vocal-heavy. Vocal-heavy music is very easy to compress compared to say something like electronic or EDM type music which will easily create distortion with lower bitrates.

I got 4 / 6 with some old Apple EarPods plugged into my laptop. I think it was probably just luck, because I picked the 128kbps MP3 for both of the ones that I got wrong.

It's fun to think that I might be able to distinguish between uncompressed audio and 320kbps MP3. I didn't think it was possible. I had a hearing test recently, and they did say that I have better than average hearing. But yeah it was probably just random.

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

#319

Post by jacquesm » Sun, Dec 09, 2018, 11:07 PM UTC

mindslight wrote: post #314

jacquesm wrote: post #276

Earlier quoted context omitted.

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 batte…

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.

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.

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

#320

Post by dextersgenius » Sun, Dec 09, 2018, 11:09 PM UTC

admax88q wrote: post #309

013a wrote: post #156

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 p…

> 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…

Have you tried using a DAC with a USB noise isolator? I don't get any hiss with my setup:

Neutron Player on Android > USB OTG cable > HiFimeDIY USB noise isolator > HiFimeDIY USB DAC > Beyerdynamic DT880

Although I don't use all that any longer, for convenience sake I just use a wireless Audiotechnica ATH-DSR9BT which supports aptX-HD and produces "good enough" quality with no hissing/noise.