Using as Car Head Unit?? - A7 General

Ok so Ive been looking in to building a Android tablet in to my car to use as a head unit.
Ive been looking around at different tablets and the A7 definitely looks the best for my budget.
Basically im running amps in my car so i need an audio signal from the unit.
I DONT want to simply run the 3.5mm headphone jack cable to the amps cause it will sound shocking.
I was just wondering if there are other ways of doing it.
I was looking in to something like sending the audio out the usb but i dont think they can do that.
But what interested me was using the HDMI audio out and using a DAC (digital audio converter i think) and converting the signal to analogue.
Does anyone know if this is possible at all or if there are better ways of doing it?
Ive been spending hours trying to find out a way of doing this!

There are converters available to go from HDMI to standard RCA outputs.

You could run the 3.5mm output through a preamp - the sound quality is pretty good, especially with good filtering, although a preamp with HDMI or SPDIF input would be better (you'll also need a HDMI-SPDIF adapter for the latter)...

Related

Audio (MP3) through original Dockingstation. HELP!

Hi,
I'm only 13 and a proud owner of an O2 XDA 2.
This I what I need help with.
I would like to place my USB docking station on top of my subwoofer, and connect my XDA with it (only for audio purposes only).
I've read some of the forums here, but didn't find much info. :?
Could someone tell me which pins, on the connector, on the dockingstation send the sound? I would like to add 2 cinch cables to these pins, and attach them to my subwoofer (to kind of make my XDA like an Ipod or another MP3 player, where I simply stick it into my dockingstation and start playing MP3s through my sound system).
Thanks,
Kind Regards,
Tony Schattat
Hi mate.
Note sure you could connect the XDA directly to a speaker as I doubt it would have the required power output (but I don't know much about this, just being logical).
Take a look at the following thread: http://forum.xda-developers.com/viewtopic.php?t=26489&highlight=
This guy has basically modified the headset to have a 3.5mm jack - I've then suggested (and intend on doing this) that you could put 2 standard audio outputs instead.
On reflection though, I think his suggestion may be better as it reduces the number of leads. If you then needed to split the sound out to 2 seperate channels you could use something like this:
http://www.maplin.co.uk/Module.aspx?ModuleNo=43086&doy=3m9
Cheers
Wayne
Hi Wayne,
Thanks for your reply.
I would rather like to have a solution which is built in my dockingstation.
With alot of precision I was able to do the following.
1. Used http://wiki.xda-developers.com/wiki/Connectors for details.
2. On pin 19 on the dockingstation I placed a 10K SMD resistor (as the standard ones are too big), connected to GND, as stated in the text.
3. Using a double cinch cable I soldered them onto pins 3 (CAR_AUDIO_R) and 4 (CAR_AUDIO_L), and both GND wires to GND.
But nothing seems to work.
I used the ohm-metre to check if the 10K resistance even came up to pin 19 of the dockingstation. I does. Unfortunately the XDA doesn't turn off it's built-in speaker and microphone, as stated in the text.
This basically simulates a car-kit for the XDA, doesn't it?
Kind regards,
Tony Schattat
Audio playback
Hiya!
Well if yer are 13 then it seems UK Schools are way behind German ones if they're teaching you about using Ohm Meters, Resistors and electronic theory already!
Ok, overall to me this whole precision soldering and resistor checking etc is all overkill for what you ultimately seem to want to achieve.
I've just bought off eBay the little 2.5 mm to 3.5mm standard headphone jack converter lead for about £2.50. I'm going to go nip into a shop or again off eBay and get a 3.5mm stereo to 2 phono plug convertor lead.
Simple case of then slapping that into the Aux input of my Hi-Fi amplifier, or my mini deck hifi etc and playing the mp3's through that!
No need for faffing around with soldering irons, and electronic theory and all that!
Added benefit is of course that through the hifi unit, I have full control over the audio equaliser functions and so will have the full spectrum of audio frequencies to hear the music - Your requirements states you just want to connect it to a subwoofer. Low frequencies are great, but you do need the upper frequencies too!
That will all set you back the grand total of about £5, and i've assumed you do have some audio equipment with an Aux input!
For 'constant' playback, when yer battery gets flat,... just plug the charger in!
Another benefit is that you can take the leads with you on your travels and setup the same at any of your friends houses with minimal effort!
I don't see the point of the route you are wishing to take - unless I'm missing something (I got in at 7am this morning after clubbing and up at midday, so im knackered!)
Cheers!
Hope this helps!
Dennis! West London UK!
Hi Dennis,
Well the schools here aren't all that far ahead ( I think, because I`ve lived in Australia for 6 years)!
It runs in the family!
I was able to find some handy info on some dockingstations on google, but I'm not very sure.
Is it true that the serial dockingstations have an audio connector on the rear side, opposite of the power connector?
Is the audio connector on the dockingstation the same thing as the one, which is found at the bottom of the XDA (would it disable the built in mic and speaker of the XDA and send the audio through connector on the back)?
If this is true, could I simply attach a 2,5mm to 3,5mm converter to the back of the dockingstation and attach the converter to my subwoofer?
Kind regards,
Tony Schattat
Audio playback
Hi there Tony
I'm still not sure exactly why you want to connect your USB cradle to play music through.... seems pointless to me..
The method I described would be the easiest for you to 'amplify' the audio output from the XDA2.
I may be wrong but I dont think the USB cradles have an 'audio output' connector at the back, it's a bit pointless as these devices aren't devised as 'audio players' - so no, you cannot put the 2.5 to 3.5 mm converter on and then connect that to your subwoofer (signal is wayyy wayyy too small to drive a sub woofer) if there is an audio output at trhe back of the usb cradle, then I never knew about it!! and same again, you cannot connect directly to a sub woofer.
Out of the socket at the bottom of the xda2 in a 2.5mm size, is an audio jack. Get the converter to take that 2.5 mm and output it to a standard 3.5mm headphone socket size. Right, at this stage you can connect 'Hifi' headphones and enjoy your MP3's that way. If you now want your music 'louder' you need to convert that (now) 3.5mm output to be able to connect it to some audio equipment that can 'amplify' the signal and play through some loudspeakers (the 3.5mm socket to Phono converter lead). That will go to your hifi amplifier in turn to which 'full range'loudspeakers are connected. You mention 'sub woofer' .. You could then attach your sub woofer to the amplifier and you will only hear the low 'rumble' of the bass frequency content of the music (again, a bit pointless!). If that's what you want then at this point all will work but then what's your plan for hearing the mid range and high frequency elements of the music?
I'm just thinking that for your final 'aim' (to hear MP3 files on the xda through loudspeakers) the method you are using is cumbersome, time consuming and pointless when you can have a 'full range' output using the method I described.
Take a look at eBay for the connectors - and you'll find you should be hearing music in no time!
Cheers! Dennis! West London UK!

HTC 8525 in car?

Alright, may be a little off subject, but I need some advice. I am trying to figure out a way to hook up my htc 8525 to my cd player in my car. Unfortunately, my cd player does have a AUX hookup, so I am not able to just buy the Mini USB to 3.5 mm cable and hard wire into my CD player through the AUX input. Any ideas on another way to do this? The car does not have blue tooth integrated neither.
Thanks in advance!
- Casper
No AUX input.. no bluetooth... kinda hard, but not impossible. Depending on the brand of your car deck, you might be able to buy an auxiliary input adapter. I know for sure that Pioneers do that. You can buy an "ipbus adapter" that plugs into the back of it where the CD changer would and you can route the audio from your phone that way. I know Alpines and Sonys also have this ability.
your best best and pretty inexpensive ...is to use a fm transmitter alongs with your Mini USB to 3.5 mm cable this is how I do it with hy 8125 and plan to do with my 8525 when I get my Mini USB to 3.5 mm cable
NRGZ28 said:
No AUX input.. no bluetooth... kinda hard, but not impossible. Depending on the brand of your car deck, you might be able to buy an auxiliary input adapter. I know for sure that Pioneers do that. You can buy an "ipbus adapter" that plugs into the back of it where the CD changer would and you can route the audio from your phone that way. I know Alpines and Sonys also have this ability.
Click to expand...
Click to collapse
Interesting.. I have a Pioneer deck, so I may be able to do it this way! Will have to check the deck after work to make sure that it has that connector on it. Thanks!
ljinsane said:
your best best and pretty inexpensive ...is to use a fm transmitter alongs with your Mini USB to 3.5 mm cable this is how I do it with hy 8125 and plan to do with my 8525 when I get my Mini USB to 3.5 mm cable
Click to expand...
Click to collapse
Yeah, I thought of this option, just hate the output quality with an FM Transmitter. Thanks!
Yeah the FM quality blows usually. Go to your local car audio shop to get one of those adapter. They're about 20 bucks. I know Best Buy has them, that's where I bought mine.
Do a search for PIE Electronics Auxilliary adapter... if your head unit has CD-Changer control ( like my Honda Pilot) then you can get a PIE adapter which basically gives you an aux input. The sound quality is FAR superior to the FM modulated stuff. The adapter takes a dual-rca style input - so you'd need the 3.5 adapter into dual rca into the PIE. Works perfectly for me with my Sirius - and if I want to listen to my 8525 I just unplug the 3.5 from my sirius and plug it into my phone
Side note - if you get a PIE adapter - do *NOT* connect the ground. I know that sounds odd but I got wicked alternator noise with the ground connected to a good ground, go ZERO noise with it disconnected entirely.
i just modded the stock headset, chopped off the headphone wires and spliced in a 1/8" male audio connector and RCA outputs, i have aftermarket radios in my rides so i have RCA inputs..
JamesHolden said:
i just modded the stock headset, chopped off the headphone wires and spliced in a 1/8" male audio connector and RCA outputs, i have aftermarket radios in my rides so i have RCA inputs..
Click to expand...
Click to collapse
Yeah, I checked my CD player yesterday, it does not have the CD changer plug. How did you do this through the RCA plugs I know my head unit has RCA plugs because I currently have my AMP hooked up to the RCA plugs. I just don't see how RCA can be used to take in sound and play it through the speakers, I thought RCA was for output. Maybe I'm wrong?
If you have that going to an amp, the RCA's you're using are "pre-amp outputs"- operative word being outputs... Most radios do not have auxilliary RCA inputs... I have a kenwood KDC-mp528 that does...
Look into _WIRED_ FM modulators
The same concept as the wireless FM deals, but without the interference and associated sound quality issues.
They basically plug in between the antenna and the head unit. when turned on, they completely replace the signal on the selected frequency so even a strong radio signal will not interfere.
The concept is well-illustrated here:
http://www.crutchfieldadvisor.com/ISEO-rgbtcspd/learningcenter/car/peripherals_installation_guide.html?page=3
Prices vary by features, but they're normally cheaper than the wireless equivalents. Look for examples here:
http://www.etronics.com/c-2435-modulators.aspx
Hope it helps!
you could just hook the 8525 up w/ the RCAs to the AMP and have a way of switching between the headunit and 8525...
just an idea
bah. go old school. tapedeck-to-headphone adapter
lovin' my 99

Am I the only one here who tries to use the Epic in a car, in a dock...??

Is anyone else trying to use a dock in their car to listen to music??
I'm on CM7 and when you use the dock in the car.....it removes all bass from the audio stream. Unless my car for some reason doesn't go through it's own amp. when using the "aux" in connection.....
I'm so frustrated at the moment, I bought a phone with all these cool hopes and dreams..
now 1.5 years later, it's ALMOST perfect (no thanks to ****sung) (thanks to DEV's!!) but I go put it in the car dock and the sound is just awful
Just wondering if anyone else has had any success ..
Using stock CM7 kernel or Shadow? From what I understand, bbelos was able to crack the code with Shadow, but maybe the devs were able to port it over to the stock one...
Sent from my SPH-D700 using xda premium
czechpunk said:
Using stock CM7 kernel or Shadow? From what I understand, bbelos was able to crack the code with Shadow, but maybe the devs were able to port it over to the stock one...
Sent from my SPH-D700 using xda premium
Click to expand...
Click to collapse
I'm using Shadow.
The dock audio works, it just sounds awful, no bass very tinny.
I should add that if you take it out of the dock and plug in an audio cable to the headphones jack and into the aux in of the car it sounds wonderful, full bass great lows and awesome highs.
From what I understand this is something that samsung made the dock do. What a horrible idea on their part.
I use my CM7 Epic in the car all the time. I don't even use the car stereo anymore. When I started using CM7 and realized the audio redirect doesn't work I went back to using what I did before we got Froyo. My stock car stereo doesn't have bluetooth so I bought this:
http://www.amazon.com/BlackBerry-Remote-Stereo-Bluetooth-Gateway/dp/B00170KUM0
It's a bluetooth gateway that uses A2DP to transmit the audio. I also use Tasker to automatically turn on bluetooth when I put the phone in the dock. The phone connects within a few seconds and everything works beautifully. It actually seems to amplify the sound some when using the gateway. I see it's like 90 bucks on amazon now. It was 30 when I bought it so i dunno. You could probably find one cheaper somewhere. But anyway, that's what I do and have had no problems.
using the bluetooth gateway is a good idea. though, imo, A2DP lacks decent quality. I have really only done A2DP streaming with Kensington's LiquidAUX receiver and the Motorola S9 headphones. I would be tempted to try the BB receiver if it was cheaper.
Samsung really dropped the ball on the desk dock. no data when the phone is in the dock while connected to USB? WTF Samsung. I would love to put another one of these in my car if it worked correctly. does the real car dock have the same issues as the desk dock? I am definitely not gonna pay $30+ for a car dock for a phone thats been out 18mo.
JojoSteez said:
I use my CM7 Epic in the car all the time. I don't even use the car stereo anymore. When I started using CM7 and realized the audio redirect doesn't work I went back to using what I did before we got Froyo. My stock car stereo doesn't have bluetooth so I bought this:
http://www.amazon.com/BlackBerry-Remote-Stereo-Bluetooth-Gateway/dp/B00170KUM0
It's a bluetooth gateway that uses A2DP to transmit the audio. I also use Tasker to automatically turn on bluetooth when I put the phone in the dock. The phone connects within a few seconds and everything works beautifully. It actually seems to amplify the sound some when using the gateway. I see it's like 90 bucks on amazon now. It was 30 when I bought it so i dunno. You could probably find one cheaper somewhere. But anyway, that's what I do and have had no problems.
Click to expand...
Click to collapse
I actually have a bunch of these, however it just isn't the same sound quality as hard wired.
^yes I agree, BT (A2DP) sound is technically compressed, and combined with a poor DAC, just isn't going to sound as warm as coming directly from the headphone jack (where the DAC has already done its work).
I just spent some time screwing around trying to find the differences in sound between the phone mounted in the dock and using the speaker out, streaming the music over BT with my Kensington LiquidAUX (outputs to 3.5mm), and plugging directly into the phone (w/ Voodoo sound).
Handsdown, best was when hooked directly into the phone. Second place went to the dock, and third was BT. I've just come to the conclusion that Samsung just didn't put any effort into this dock, and the actual DAC inside the dock, just sucks. This is all just going on the assumption that the audio coming out of the USB is digital, and the digital-analog conversion is being done in the dock itself. Seems like the simplest explanation that the output from the USB port is a digital output. My car stereo is a 2008 Mazda Bose system with a 3.5in AUX input.
Now my question is, where can I get a USB-[single]RCA so I can use the phone as a digital output connection with a decent DAC...
dzl said:
^yes I agree, BT (A2DP) sound is technically compressed, and combined with a poor DAC, just isn't going to sound as warm as coming directly from the headphone jack (where the DAC has already done its work).
I just spent some time screwing around trying to find the differences in sound between the phone mounted in the dock and using the speaker out, streaming the music over BT with my Kensington LiquidAUX (outputs to 3.5mm), and plugging directly into the phone (w/ Voodoo sound).
Handsdown, best was when hooked directly into the phone. Second place went to the dock, and third was BT. I've just come to the conclusion that Samsung just didn't put any effort into this dock, and the actual DAC inside the dock, just sucks. This is all just going on the assumption that the audio coming out of the USB is digital, and the digital-analog conversion is being done in the dock itself. Seems like the simplest explanation that the output from the USB port is a digital output. My car stereo is a 2008 Mazda Bose system with a 3.5in AUX input.
Now my question is, where can I get a USB-[single]RCA so I can use the phone as a digital output connection with a decent DAC...
Click to expand...
Click to collapse
I actually bought a mini amp for a car just to put inbetween the dock out and my aux in......thinking it'd solve the problem.
Sadly while the sound was awesome, there was a ton of static and other noise even with a ground loop isolator in the mix.
If you figure out a way to get good sounding audio out of the dock while in a car......pleaseee post it up!! For now I guess it's back to bluetooth...it's better then having to manually plug in the sound and power each time i get in....
I just use fm transmitter w/ DSM manager n voodoo control plus, Bass is up bumpin.
Sent from my SPH-D700 using xda premium
Eh, the BT gateway is not going to give you the same as hard wired. Nothing will beat hardwired. I don't notice enough difference for it to matter, although my car is all stock. I'm big into home stereo, but never cared to spend the money in my car. I don't spend enough time in there to justify it. But to each his own, just a suggestion. Mine sounds better to me through BT than the dock, but that could be something with my stereo.
---------- Post added at 04:42 PM ---------- Previous post was at 04:41 PM ----------
J3ff said:
...it's better then having to manually plug in the sound and power each time i get in....
Click to expand...
Click to collapse
This is my main reason for the BT gateway. It defeats the purpose of having a dock, if I have to plug in cable separately. Now I just throw the phone in the dock, slide the connector over, start whatever music app I feel like using and I'm on my way.
Are you using the stock radio in your car? The Epic dock output is not amplified, so if the input on your stereo is made for a amplified output (headphone output for example) then you will have a tinny sound.
Most aftermarket receivers will work with both unamplified outputs and amplified outputs, for example on my Pioneer MVH-P8200BT there is not much difference between with the dock and straight from the headphone output (without Voodoo Sound of course).
tbob18 said:
Are you using the stock radio in your car? The Epic dock output is not amplified, so if the input on your stereo is made for a amplified output (headphone output for example) then you will have a tinny sound.
Most aftermarket receivers will work with both unamplified outputs and amplified outputs, for example on my Pioneer MVH-P8200BT there is not much difference between with the dock and straight from the headphone output (without Voodoo Sound of course).
Click to expand...
Click to collapse
yes that's the problem.
I'm in a lexus is350 awd ..
I assume that the AUX in for some reason doesn't run through the car's amplifier ??
tbob18 said:
Are you using the stock radio in your car? The Epic dock output is not amplified, so if the input on your stereo is made for a amplified output (headphone output for example) then you will have a tinny sound.
Most aftermarket receivers will work with both unamplified outputs and amplified outputs, for example on my Pioneer MVH-P8200BT there is not much difference between with the dock and straight from the headphone output (without Voodoo Sound of course).
Click to expand...
Click to collapse
So you can confirm that the sound is just as good as the headphone out? I have been on the fence about getting a dock, i have an older Pioneer deck & its sound is grate with the headphone jack.
also does any one know of a way to get voodoo with the dock, or is that just imposable?
zman519 said:
So you can confirm that the sound is just as good as the headphone out? I have been on the fence about getting a dock, i have an older Pioneer deck & its sound is grate with the headphone jack.
also does any one know of a way to get voodoo with the dock, or is that just imposable?
Click to expand...
Click to collapse
According to supercurio, at least regarding my transformer, it is all about the headphone jack hardware that is why bt output does not get voodoo controls on og transformer, i assume the same is true with epic..
J3ff said:
yes that's the problem.
I'm in a lexus is350 awd ..
I assume that the AUX in for some reason doesn't run through the car's amplifier ??
Click to expand...
Click to collapse
It definitely runs through the amplifier, however it is probably calibrated for a headphone output and not a Line-Out output. The only time I have experienced the "tinny" sound is if I hook up headphones to the dock.
zman519 said:
So you can confirm that the sound is just as good as the headphone out? I have been on the fence about getting a dock, i have an older Pioneer deck & its sound is grate with the headphone jack.
also does any one know of a way to get voodoo with the dock, or is that just imposable?
Click to expand...
Click to collapse
As I said, on my system there is little difference.. Granted, the speakers I have are not exactly high-end, they are aftermarket and better than most stock speakers.
I have confirmed this by testing the dock on my Monitors. Volume and sound is very close. On my monitors the dock is a bit louder, not quite as clear with a bit too much midbass and over-emphasized highs - slightly compressed sounding. Lower bass levels are nearly identical.
I do not notice this in my car whatsoever. But my monitors cost 5x as much as the component set in my car, so that is expected.
As far as I know there is no way to use Voodoo Sound with the dock.
I have the CleanGB ROM installed and use the stock car dock. I get perfect audio output to my car stereo using a 3.5mm mic -to- RCA cord.
haas599 said:
I have the CleanGB ROM installed and use the stock car dock. I get perfect audio output to my car stereo using a 3.5mm mic -to- RCA cord.
Click to expand...
Click to collapse
reallyyyyy and lots of bass? stock car stereo ??
Stock Epic / stock stereo
I have (almost) completely stock Epic (only non-rooted GPS_Fix.zip) and stock stereo (Lexus ES350) and Samsung Car Dock. I use the Dock Sound Redirect app from the Market to direct sound from E4G thru USB to dock stereo phone jack to Aux in on car stereo. The overall sound is fine; not the same as a high-end home stereo but as good as the car stereo & CD. The volume is slightly lower due to non-amped input. Nav audio also runs through this route. Perhaps the issue is stock vs CM7? The Sammy Car Dock works fine for me with the Sound Redirect app.
J3ff said:
I'm on CM7 and when you use the dock in the car.....it removes all bass from the audio stream. Unless my car for some reason doesn't go through it's own amp. when using the "aux" in connection.....
Click to expand...
Click to collapse
J3ff, I feel your pain. I bought the Epic shortly after it came out, and the car dock about a year ago. There's a world of difference in audio quality between the headphone jack and the USB audio output that the dock uses. I've used the dock on Froyo, Gingerbread, stock and custom ROM's, it doesn't matter. Haven't tried Shadow kernel on CM7 yet.
The problem becomes even more apparent if you're using something like Voodoo Sound, which affects the headphone jack output but not the USB audio output. I believe Voodoo (and probably DSP Manager, etc., but I can't confirm that) affect the audio on the DAC on the headphone jack, but since the process of converting audio for the USB output is different (and it's not using the Wolfson WM8994 as far as I know)...
I ended up reverting to a $5 cheapo generic car dock that attaches to an A/C vent so I could still use the headphone jack for audio output
rsage said:
J3ff, I feel your pain. I bought the Epic shortly after it came out, and the car dock about a year ago. There's a world of difference in audio quality between the headphone jack and the USB audio output that the dock uses. I've used the dock on Froyo, Gingerbread, stock and custom ROM's, it doesn't matter. Haven't tried Shadow kernel on CM7 yet.
The problem becomes even more apparent if you're using something like Voodoo Sound, which affects the headphone jack output but not the USB audio output. I believe Voodoo (and probably DSP Manager, etc., but I can't confirm that) affect the audio on the DAC on the headphone jack, but since the process of converting audio for the USB output is different (and it's not using the Wolfson WM8994 as far as I know)...
I ended up reverting to a $5 cheapo generic car dock that attaches to an A/C vent so I could still use the headphone jack for audio output
Click to expand...
Click to collapse
Just flip the dock upside down.

Optical audio out (spdif/toslink)

(sorry I can't post any links, but you can google the words in bold)
Are there any Android head units that support optical audio out?
I've been researching the last few nights (hours!) for a WIRED way to get a toslink optical cable to a Audison Prima AP8.9 Amp/DSP.
Are there any electrical engineers out there who have thought about bypassing the onboard DAC to get digital output?
Or.... is my only option to provide <96kHz optical audio to get an AptX lossless Bluetooth receiver like the Neet AptX lossless bluetooth receiver. Can anyone share experience on how well the Android units perform constantly connected to a BT receiver for all car audio? Esp. if you have the new Pumpkins with the Parrot BT card, in case that improves things.
Thanks!
I'm looking for the same answer, i've installed the neet receiver, but unfortunate for me, the head unit does not connect. I don't think it can be used as transmitter.
I've found this, but I don't know if it works...
http://www.matrix-digi.com/en/products/158/index.html
You all may be overthinking this. Turns out plenty of modern android devices can use standard USB audio hardware. You just need an OTG cable, and the kind of USB audio output device that doesn't need a specialized driver under Windows or Linux. I've hooked up many different USB audio dongles you my Galaxy S3 and S4. The S4 wouldn't charge while hooked through the particular OTG cable, but the S3 does. As a matter of fact, I've been using it as the media player in my car for years.
Admittedly, I've only used the optical out on some of my devices occasionally, but I imagine it would still work for most.
Update: Not all supposed "OTG" cables work. This is the one I bought in Jan 2014 that works for both audio and charging on my S3 with CyanogenMod 11: https://www.amazon.com/gp/product/B009YPYORM/
Today I received an Android 6.0 Head Unit from A-Sure for an Audi A3. I connected a Terratec Aureon Dual USB DAC. I got sound, but couldn't control the volume. Changing the android system volume had no effect.
I am considering spending a couple of bucks on the app "USB Audio Player PRO" and test it again. If this doesn't work, i will have to return the unit.
Greetings from Germany
So i had to return the Head Unit. I tried a different one by "Skandinav", with this one there was no sound at all from the USB DAC
retlaps said:
Today I received an Android 6.0 Head Unit from A-Sure for an Audi A3. I connected a Terratec Aureon Dual USB DAC. I got sound, but couldn't control the volume. Changing the android system volume had no effect.
I am considering spending a couple of bucks on the app "USB Audio Player PRO" and test it again. If this doesn't work, i will have to return the unit.
Greetings from Germany
Click to expand...
Click to collapse
Hi,
You need to connect to DAC with digital volume control like Helix DSP Pro
Greetings from Singapore
daviestar said:
(sorry I can't post any links, but you can google the words in bold)
Are there any Android head units that support optical audio out?
I've been researching the last few nights (hours!) for a WIRED way to get a toslink optical cable to a Audison Prima AP8.9 Amp/DSP.
Are there any electrical engineers out there who have thought about bypassing the onboard DAC to get digital output?
Or.... is my only option to provide <96kHz optical audio to get an AptX lossless Bluetooth receiver like the Neet AptX lossless bluetooth receiver. Can anyone share experience on how well the Android units perform constantly connected to a BT receiver for all car audio? Esp. if you have the new Pumpkins with the Parrot BT card, in case that improves things.
Thanks!
Click to expand...
Click to collapse
yes, you can connect to the DAC, thereby outputting digital audio from applications and transport flash drive.
this can be done not only with android devices, but also with conventional tape recorder, some installations you can look at my YouTube channel
unfortunately links for new users are forbidden, you can search by my nickname - "jonjonni toslink Евгений Фещенко"
daviestar said:
(sorry I can't post any links, but you can google the words in bold)
Are there any Android head units that support optical audio out?
I've been researching the last few nights (hours!) for a WIRED way to get a toslink optical cable to a Audison Prima AP8.9 Amp/DSP.
Are there any electrical engineers out there who have thought about bypassing the onboard DAC to get digital output?
Or.... is my only option to provide <96kHz optical audio to get an AptX lossless Bluetooth receiver like the Neet AptX lossless bluetooth receiver. Can anyone share experience on how well the Android units perform constantly connected to a BT receiver for all car audio? Esp. if you have the new Pumpkins with the Parrot BT card, in case that improves things.
Thanks!
Click to expand...
Click to collapse
Well, don't fall into this hole. (warning to new users)
I have the Prima dac/amp, and the sound is amazing, and it can be connected to an Android phone via OTG to Toslink adapter, or via Bluetooth adapter with Toslink out, but it has one very nasty issue: when the amp is starting, and there is no Toslink signal, it won't register the connection. So if you later connect your phone, you have to cycle through the input sources Digital->Aux->Master->Digital to again register your connection.
So unless you connect your phone or turn on your BT receiver _before_ you start the car up, you will need to fiddle with cycling the source (while also driving the car). (That is if you also have the optional control unit with a display.)
Why they designed the device this way is just beyond me.
I hope its all right to join an old discussion.
I have a similar problem, I want to connect an android head unit in my car to an external digital amplifier. The amplifier itself have SPDIF input (mosconi GALDEN Pico 12 channels https://mosconi-system.it/product/gladen-pico-812-dsp/) but I can't find an android head unit running Android 10 with SPDIF output for my car. I've found converting card USB->SPIDF (for example: https://www.amazon.com/Douk-Audio-C...1&keywords=usb+to+spdif&qid=1617899902&sr=8-3) but I still missing some points:
-In Android 10, how do I switch all audio outputs to the converting card? Is it a part of the Android or external application?
-What happen when playing multi channel media (such as 5.1)? does each channel transfer on each on?
-Is it possible to use the same method to BT? The Pico have an optional BT card.
Thanks in advance, Haim
haim_gds said:
-In Android 10, how do I switch all audio outputs to the converting card? Is it a part of the Android or external application?
Click to expand...
Click to collapse
Android usually automatically switches to USB audio when found, but many implementations do not. Sometimes there's a setting in the developer menu for prioritizing USB audio, but sometimes that doesn't do anything.
USB audio of any kind is not supported on my Sony X800D Android TV.
haim_gds said:
-What happen when playing multi channel media (such as 5.1)? does each channel transfer on each on?
Click to expand...
Click to collapse
Multichannel USB sometimes works, and sometimes doesn't. Certainly it can work, such as on many Android TV implementations like NVIDIA shield.
haim_gds said:
-Is it possible to use the same method to BT? The Pico have an optional BT card.
Click to expand...
Click to collapse
Multichannel Bluetooth is not a standard, although some implementations like enhanced aptX can support it.
Have you also considered that SPDIF surround is always encoded, and thus is output at a fixed volume? Your head unit would not be able to control the volume; it would have to be done after decoding, like at the power amplifier stage.
MarkerB said:
Android usually automatically switches to USB audio when found, but many implementations do not. Sometimes there's a setting in the developer menu for prioritizing USB audio, but sometimes that doesn't do anything.
USB audio of any kind is not supported on my Sony X800D Android TV.
Multichannel USB sometimes works, and sometimes doesn't. Certainly it can work, such as on many Android TV implementations like NVIDIA shield.
Multichannel Bluetooth is not a standard, although some implementations like enhanced aptX can support it.
Have you also considered that SPDIF surround is always encoded, and thus is output at a fixed volume? Your head unit would not be able to control the volume; it would have to be done after decoding, like at the power amplifier stage.
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Click to collapse
Do you know of if it's possible to allow the headunits to play higher than 48khz resolution through the optical or coax outputs ?
dfal47 said:
Do you know of if it's possible to allow the headunits to play higher than 48khz resolution through the optical or coax outputs ?
Click to expand...
Click to collapse
Have to ask - what
marchnz said:
Have to ask - what
Click to expand...
Click to collapse
The unit forces 24b 48khz audio, coaxial can output 192khz tracks and optical upto 96khz . Higher resolution audio output.
Neutron or UAPP will allow higher resolution, but you'll probably lose Navi directions as those programs bypass the android audio layer and mixer.
Basically you need a high resolution non- Android media player, with a navi input and mixer, that also has an spdif output.
The Alpine UTX-A09 looks like it can do that, assuming it isn't Android based /doesn't force 16/48 output from all sources when the mixer is enabled (in non "Alpine Direct" mode). Looks like the Alpine pxe-x09 has a mixer, so it should also be able to mix in navigation instructions.
Some of the Helix DSPs may mix or prioritize different inputs - the documentation isn't clear.
If you use spdif connection vs optical you run the risk of creating a ground loop unless the source is floating ie running on its battery power.
You can blow out all your high frequency drivers in a second if the ground loop creates feedback oscillations.
A common ground point may or may not prevent it. Using toslink to couple eliminates this potential issue.
For car hookups best practice to use heavy gauge wire for positive* feed, preferably coming directly from the battery for high wattage amps, source auxiliary equipment from the same end point. Do not daisy chain.
Same is true with home hifi, avoid using spdif cables to couple amps, preamps, receivers, cable boxes, etc. Amps, recievers are designed to be floating and not connected to ground. Do mix earth grounded and floating equipment unless connected by toslink only ie a tower PC with a 3 prong plug and a reciever (2 prong plug, floating).
*if you use a chassis grounding point, use only one and do not daisy chain!
dfal47 said:
Do you know of if it's possible to allow the headunits to play higher than 48khz resolution through the optical or coax outputs ?
Click to expand...
Click to collapse
Sorry for the delay.
DTS has had 96kHz/24 bit for many years, and they work through any SPDIF interface... as you wanted. They don't actually change the hardware interface speed, but rather encode the extra data into the sales 48kHz stream.
I've never bothered to encode anything with it, because I'm guessing it actually makes compression worse. You're squeezing much more data through the same early 90s compression algorithm, and DTS is already lossy enough. Factor-in that higher sample rates are not detectable in blind tests, and it just seems like a bad idea.
Hmm... Unless the 96kHz/24 bit extension algorithm is much more efficient at compression, considering it was introduced much later than the base DTS algorithms in 1991, and may have leveraged more recent technologies. In that case, it would definitely be the better choice. Unfortunately, I haven't read anything about this possibility.
Good reading on the 96kHz/24 bit topic:
DTS (company) - Wikipedia
en.m.wikipedia.org
Get the Rundown on the DTS 96/24 Audio Format
DTS 96/24 is part of the DTS family of audio formats but it's rather rare since the advent of Blu-ray Disc.
www.lifewire.com
Bumping an old, but good, thread. I have exactly the same amp (well, the 5.9), and an Android unit with a TOSlink port - but it seems to be turned off as I can’t see any light coming from the TOSlink cable. Any idea how to turn it on?
I have a FiiO as a backup but prefer not to do SPDIF because I need another device for the Audison to take SPDIF input …
MarkerB said:
Sorry for the delay.
DTS has had 96kHz/24 bit for many years, and they work through any SPDIF interface... as you wanted. They don't actually change the hardware interface speed, but rather encode the extra data into the sales 48kHz stream.
I've never bothered to encode anything with it, because I'm guessing it actually makes compression worse. You're squeezing much more data through the same early 90s compression algorithm, and DTS is already lossy enough. Factor-in that higher sample rates are not detectable in blind tests, and it just seems like a bad idea.
Hmm... Unless the 96kHz/24 bit extension algorithm is much more efficient at compression, considering it was introduced much later than the base DTS algorithms in 1991, and may have leveraged more recent technologies. In that case, it would definitely be the better choice. Unfortunately, I haven't read anything about this possibility.
Good reading on the 96kHz/24 bit topic:
DTS (company) - Wikipedia
en.m.wikipedia.org
Get the Rundown on the DTS 96/24 Audio Format
DTS 96/24 is part of the DTS family of audio formats but it's rather rare since the advent of Blu-ray Disc.
www.lifewire.com
Click to expand...
Click to collapse
Toslink can support 24 bit/192 khz.
Optical coupling is preferred as it carries no risk of creating ground loops; optical isolation.
A ground loop can smoke (literally) all your tweeters and maybe the power amp in a second.
blackhawk said:
Toslink can support 24 bit/192 khz.
Optical coupling is preferred as it carries no risk of creating ground loops; optical isolation.
A ground loop can smoke (literally) all your tweeters and maybe the power amp in a second.
Click to expand...
Click to collapse
I think you accidentally replied to the wrong post. My topic was about the quality of the DTS 96kHz/24 bit encode, which is completely independent of which of the two physical SPDIF interfaces is used.

Android 5.1 head unit >>> USB Audio (DAC) output

Hi, I installed a MTCD Android head unit with Android 5.1.1 in my car two weeks ago. (I could'nt start this thread in the MTCD section because I'm new here)
My car audio setup goes as follow: Android Head Unit >>> USB Cable >>> PCM2704 USB to SPDIF adapter >>> SPDIF coax cable >>> MiniDSP 6x8 >>> 3 Amps >>> Speakers + sub.
So far I've been able to get SPDIF sound output with Neutron (Direct USB mode), Onkyo HF Player, USB Audio Player Pro, HibyMusic Player.
Sound is amazing btw.
If I understand correctly, all these apps are working with the USB DAC because they use their own app's USB Driver.
Important to know: All song in 44khz are playing fine, songs in 48khz makes every app freeze. I got a way around this by setting Neutron to resample every song in 44khz, so all songs are working now.
Now, if I play a song in Google Play Music, Spotify, Kodi, etc no sound comes out ... same thing for my HU video app, phone calls etc.
Is there a way around this ? What modifications can be made so every sound outputs to the USB Audio ? IE. kernel update, system files modifications etc ??
Thanks for any input.
Nobody use a USB DAC with his head unit ?
I have found this thread: http://forum.xda-developers.com/showpost.php?p=66707293&postcount=47
But I dont think it applies to Android 5.1, sound management is different.
i dont use any DAC on this head unit. But I do have a Dragonfly USB DAC on my computer. the Dragonfly Red says it works with Android. Not sure if that is just marketing, or if it doesn't something specific.
CadillacMike said:
i dont use any DAC on this head unit. But I do have a Dragonfly USB DAC on my computer. the Dragonfly Red says it works with Android. Not sure if that is just marketing, or if it doesn't something specific.
Click to expand...
Click to collapse
Can you try it please ?
DanB0y said:
Can you try it please ?
Click to expand...
Click to collapse
i dont know how I would even go about hooking it up? i could plug it into the USB port, but then what? use headphones?
all my speakers go through the wiring harness
CadillacMike said:
i dont know how I would even go about hooking it up? i could plug it into the USB port, but then what? use headphones?
all my speakers go through the wiring harness
Click to expand...
Click to collapse
you would need to be using pre-outs, using a 3.5mm to rca cable into an external amp.
---------- Post added at 09:03 AM ---------- Previous post was at 08:57 AM ----------
interesting that you've tried this. This forces you to completely by-pass the HUs sound processing.
I have the same DSP, but I'm using direct pre-outs. I like this idea though bc it gets around the low pre-out voltage, and allows you to ignore the poorly implemented sound processing in the HU.
Unfortunately, you probably need to modify the filesystem to get this to work, as your link shows. Why do you feel the need to use a DAC in addition to the DSP?
Hisma said:
you would need to be using pre-outs, using a 3.5mm to rca cable into an external amp.
Click to expand...
Click to collapse
my sub is tapped into my speaker wires, so I dont use the RCA preouts. So I probably can't try this.
However, I think my audio is pretty great with the Joying
CadillacMike said:
i dont know how I would even go about hooking it up? i could plug it into the USB port, but then what? use headphones?
all my speakers go through the wiring harness
Click to expand...
Click to collapse
Yes simply use headphones
We just need to know if audio is outputing from the DAC.
I would appreciate, thanks !
Hisma said:
Unfortunately, you probably need to modify the filesystem to get this to work, as your link shows. Why do you feel the need to use a DAC in addition to the DSP?
Click to expand...
Click to collapse
The DAC is a really clean source signal VS the head unit, I have a 2000$+ sound system in my car and sound quality is very important to me.
Also, DAC is digital signal VS analog RCA outputs on the head unit.
DanB0y said:
The DAC is a really clean source signal VS the head unit, I have a 2000$+ sound system in my car and sound quality is very important to me.
Also, DAC is digital signal VS analog RCA outputs on the head unit.
Click to expand...
Click to collapse
I agree. I feel like right now my HU is the "weak point" of my system. I am about the same as you, roughly $2000 in equipment (probably a little more).
focal KRX3 3-way active system w/ a cheap kicker sub + 3 amps. I have the C-DSP along w/ a line driver to manage the low pre-out voltage. Would love to take the line driver out of the signal chain if I could. All these components are taking up a lot of valuable space.
I hope you figure this out. I don't have a MTCD, I have a non-joying 4.4 HU. Would love to use the SPDIF inputs on the C-DSP as opposed to the ****ty pre-outs from the HU.
Hisma said:
I agree. I feel like right now my HU is the "weak point" of my system. I am about the same as you, roughly $2000 in equipment (probably a little more).
focal KRX3 3-way active system w/ a cheap kicker sub + 3 amps. I have the C-DSP along w/ a line driver to manage the low pre-out voltage. Would love to take the line driver out of the signal chain if I could. All these components are taking up a lot of valuable space.
I hope you figure this out. I don't have a MTCD, I have a non-joying 4.4 HU. Would love to use the SPDIF inputs on the C-DSP as opposed to the ****ty pre-outs from the HU.
Click to expand...
Click to collapse
Nice ! I have 3 way peerless (tweets + 3.5 mids + 7in woofer) 1 pioneer amp 4ch for tweets + mids and 1 pioneer amp 2ch for the woofers, another JBL amp in the trunk with a 15in Alpine Type-R. I have the C-DSP 6X8 MiniDSp as well
SPDIF to C-DSP SPDIF Input would give you 4V at the MiniDSP RCA outputs
DanB0y said:
SPDIF to C-DSP SPDIF Input would give you 4V at the MiniDSP RCA outputs
Click to expand...
Click to collapse
well you have convinced me to give this a shot. The USB DAC + 25 ft coax cable only set me back $35 on amazon. So even if this doesn't work I won't be mad.
The potential for 4V of CLEAN pre-out voltage is too enticing to pass up. The line driver works, but like I said it's another box that needs power/space/etc. The USB DAC also allows me to take the HU sound processor fully out of my signal chain.
I am unfortunately using android 4.4, so dont think I can help you much, but I will let you know if this works nonetheless.
Hisma said:
well you have convinced me to give this a shot. The USB DAC + 25 ft coax cable only set me back $35 on amazon. So even if this doesn't work I won't be mad.
The potential for 4V of CLEAN pre-out voltage is too enticing to pass up. The line driver works, but like I said it's another box that needs power/space/etc. The USB DAC also allows me to take the HU sound processor fully out of my signal chain.
I am unfortunately using android 4.4, so dont think I can help you much, but I will let you know if this works nonetheless.
Click to expand...
Click to collapse
If it dont work natively, I'm 99% sure it will work with the Neutron music player. Install it and then go to hardware settings and enable Direct USB Driver. :good:
DanB0y said:
If it dont work natively, I'm 99% sure it will work with the Neutron music player. Install it and then go to hardware settings and enable Direct USB Driver. :good:
Click to expand...
Click to collapse
well I tested this today and I am very pleased with the results. I really do notice a difference in SQ. It sounds "cleaner" and fuller.
Only major thing I notice is the overall volume seems really high over SPDIF. Only place I can adjust the volume now is with the DSP, but even then, I find I need to turn the gain down on the SPDIF inputs to get an acceptable volume. This is even with gain all the way down on my amps. This leads to a bit of clipping on the highs.
Did you make any adjustments in neutron player or the DSP to get an acceptable volume? Or do you get by with just adjusting the DSP master volume?
Now I just need to see if I can get all my sound to route through. I like to listen to streaming music too but I don't think I can go back to using analog pre-outs.
Hisma said:
well I tested this today and I am very pleased with the results. I really do notice a difference in SQ. It sounds "cleaner" and fuller.
Only major thing I notice is the overall volume seems really high over SPDIF. Only place I can adjust the volume now is with the DSP, but even then, I find I need to turn the gain down on the SPDIF inputs to get an acceptable volume. This is even with gain all the way down on my amps. This leads to a bit of clipping on the highs.
Did you make any adjustments in neutron player or the DSP to get an acceptable volume? Or do you get by with just adjusting the DSP master volume?
Now I just need to see if I can get all my sound to route through. I like to listen to streaming music too but I don't think I can go back to using analog pre-outs.
Click to expand...
Click to collapse
Great ! Now you're in the same boat as me lol
(Except for the clipping, I have no problem with that)
What is the model of your amps ? I have my gain to around 1/3 in the amps (They're up to 6.5V input sensitivity) and spdif input gain is at 0.
For your sound routing, you can sum the rca inputs and the spdif input together in the DSP And then you use your input levels to match the loudness. That way, you'll be able to listen excellent SQ music from Neutron and still hear BT phone calls, Youtube, navigation etc trough the analog inputs.
DanB0y said:
Great ! Now you're in the same boat as me lol
(Except for the clipping, I have no problem with that)
What is the model of your amps ? I have my gain to around 1/3 in the amps (They're up to 6.5V input sensitivity) and spdif input gain is at 0.
For your sound routing, you can sum the rca inputs and the spdif input together in the DSP And then you use your input levels to match the loudness. That way, you'll be able to listen excellent SQ music from Neutron and still hear BT phone calls, Youtube, navigation etc trough the analog inputs.
Click to expand...
Click to collapse
Yes! This is exactly what I have done. I spoke too soon also. The clipping was more a tuning issue than anything (changed cross-over on tweeters & lowered their output a bit). I was able to set the gain on SPDIF back to 0.
Man it sounds really good now. I haven't any real tuning yet outside of setting gains and cross-overs. I think once I tune the system it'll take it over the top.
I have a mosconi as100.4 on the tweeters and mids, and a alpine mrv-m500 on the sub. (i have one other amp I am replacing to power mid woofer, should arrive tomorrow). It's a total overkill system, but I find great deals on used gear on diymobileaudio classifieds so I keep upgrading lol.
So now I will use neutron for majority of listening, and by mixing channels together on the analogs I already had connected, I get acceptable SQ for phone calls and streaming music. I have no desire to mod my system files the way it was shown in that thread you linked. Looks too risky. I am okay with this new arrangement since 90+% of my listening is my personal music collection.
Really appreciate you making this thread. I always knew my system was capable of sounding better and this did the trick. I will let you know if I figure anything else out that could be useful.
Hisma said:
Yes! This is exactly what I have done. I spoke too soon also. The clipping was more a tuning issue than anything (changed cross-over on tweeters & lowered their output a bit). I was able to set the gain on SPDIF back to 0.
Man it sounds really good now. I haven't any real tuning yet outside of setting gains and cross-overs. I think once I tune the system it'll take it over the top.
I have a mosconi as100.4 on the tweeters and mids, and a alpine mrv-m500 on the sub. (i have one other amp I am replacing to power mid woofer, should arrive tomorrow). It's a total overkill system, but I find great deals on used gear on diymobileaudio classifieds so I keep upgrading lol.
So now I will use neutron for majority of listening, and by mixing channels together on the analogs I already had connected, I get acceptable SQ for phone calls and streaming music. I have no desire to mod my system files the way it was shown in that thread you linked. Looks too risky. I am okay with this new arrangement since 90+% of my listening is my personal music collection.
Really appreciate you making this thread. I always knew my system was capable of sounding better and this did the trick. I will let you know if I figure anything else out that could be useful.
Click to expand...
Click to collapse
Yeah I know what overkill sounds like haha
For frontstage 3way I got a 4ch Pioneer Premier PRS-X340 running 2x NE25-VTS04 Peerless tweets and 2x NE95W-04 3in Peerless mids, another Pioneer old scholl amp pushing 2x175w for 7in Wavecor woofers. In the trunk is a JBL GTO14001, 1500Wrms @2ohm pushing a 15In Alpine Type-R sub in 3.5cuft tuned @21hz
All my amps are very good condition used gear found on classifieds too, you can dig some real treasors for very little money sometimes !
I've been looking all around the web since last week for how to route every sounds of the HU to a USB DAC, translating and reading about 500 pages worth of XDA/Russian Android forums, spent last nights editing config files all around my HU System folder, I tried the how-to link I posted in OP for MTCB units, nothing to do.. I really think the Kernel must be enabled for USB Audio for it to work, my DAC shows up in USB devices info but not in the audio output devices.
Well, I'm still happy because my FLAC music collection plays incredibly well i dont car that much for FM Radio SQ, I only wish I'd be able to listen to Spotify or Kodi on the DAC.
Im r eally glad if I could be any help to you and will keep this thread updated if I find something !
navigation guidance voice goes through usb audio ?
DanB0y said:
Yeah I know what overkill sounds like haha
For frontstage 3way I got a 4ch Pioneer Premier PRS-X340 running 2x NE25-VTS04 Peerless tweets and 2x NE95W-04 3in Peerless mids, another Pioneer old scholl amp pushing 2x175w for 7in Wavecor woofers. In the trunk is a JBL GTO14001, 1500Wrms @2ohm pushing a 15In Alpine Type-R sub in 3.5cuft tuned @21hz
All my amps are very good condition used gear found on classifieds too, you can dig some real treasors for very little money sometimes !
I've been looking all around the web since last week for how to route every sounds of the HU to a USB DAC, translating and reading about 500 pages worth of XDA/Russian Android forums, spent last nights editing config files all around my HU System folder, I tried the how-to link I posted in OP for MTCB units, nothing to do.. I really think the Kernel must be enabled for USB Audio for it to work, my DAC shows up in USB devices info but not in the audio output devices.
Well, I'm still happy because my FLAC music collection plays incredibly well i dont car that much for FM Radio SQ, I only wish I'd be able to listen to Spotify or Kodi on the DAC.
Im r eally glad if I could be any help to you and will keep this thread updated if I find something !
Click to expand...
Click to collapse
Any update on this thread ?
I made some sort of experiance, on Joying HU , the 2GB Rockchip Sofia version (10.1" screen) :
Using info from https: // source.android.com/devices/audio/usb.html - i looked into the "audio_policy.conf" file on the Joying, and for sure , there was no reference to any USB audio interface.
I am no android expert .. but i edited this file , with the info gathered from the link above , and after a reboot - the HU did indeed send the audio to the USB port.
Audio from all the apps i tred , was routed to the USB interface (Radio , DAB player,Kodi etc..)
The bad thing (?) - there was no volume control , all audio is at max level.
An external volume control could possibly remedy this.. i will look into it
Frank

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