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Documentation of MTC_RK3188_REV0.3 board?

Some one have documaentation of MTC_RK3188_REV0.3 board?
I buy a unit without any Micro SD card slot, the main board have connection for SD and GPS sd slots, I can made a SD boards
Right now I map the connectors pin to a board pins, but I need to know wich pin correspond to wich signal for SD card.
Connectors:
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Signals to main board:
Main Board:
SD signals:
Or if some one have a similar unit and can be map the pins of the connector to a SD card slot I appreciate.

This looks like a fun hackaday post. It's almost making me want to pull my unit to take a few photos for future study.
I'm interested in the amp equipment. The preamp is weak in my RK3188. They claim 45wX4 or whatever but their own specs are that that's max but you begin to clip and introduce noise at only 16w! That's "12" on the volume dial.
It looks like the RCA outputs are low line outputs but they have them going to headrest tvs in the pictorial. I'm going to assume I can just take those and run them to a proper amp and get better sound quality out of this system.
Anyway, it'd be nice to know what electronics are doing the lifting. Right now if I crank it above about 12 I start to notice significant signal degradation in the highs. They get all fuzzy and just sound yukky.

Attrezzo Pox said:
This looks like a fun hackaday post. It's almost making me want to pull my unit to take a few photos for future study.
I'm interested in the amp equipment. The preamp is weak in my RK3188. They claim 45wX4 or whatever but their own specs are that that's max but you begin to clip and introduce noise at only 16w! That's "12" on the volume dial.
It looks like the RCA outputs are low line outputs but they have them going to headrest tvs in the pictorial. I'm going to assume I can just take those and run them to a proper amp and get better sound quality out of this system.
Anyway, it'd be nice to know what electronics are doing the lifting. Right now if I crank it above about 12 I start to notice significant signal degradation in the highs. They get all fuzzy and just sound yukky.
Click to expand...
Click to collapse
Do you happen to know at what volume the RCAs start to clip ?

DanB0y said:
Do you happen to know at what volume the RCAs start to clip ?
Click to expand...
Click to collapse
Not sure. Is suspect they don't the high output is a function of the internal amp. I believe if you use the preamp outputs you bypass all of that.
I dug a little deeper and my biggest issue WAS bluetooth. If I used AirPlay/DLNA Receiver to stream over wifi the majority of the distortion goes away.
It's back to acceptable.

Attrezzo Pox said:
Not sure. Is suspect they don't the high output is a function of the internal amp. I believe if you use the preamp outputs you bypass all of that.
I dug a little deeper and my biggest issue WAS bluetooth. If I used AirPlay/DLNA Receiver to stream over wifi the majority of the distortion goes away.
It's back to acceptable.
Click to expand...
Click to collapse
Ok thanks. Im using an external USB DAC with Neutron audio player (sounds absolutely awesome) with spdif out to my DSP but wanted to level-match the RCA outouts of the HU in my MiniDSP so Bluetooth telephone and FM Radio sounds as loud as the DAC... Best thing would be to be able to hear every single sounds of the Head Unit on the USB DAC, but so far only apps that use their own USB drivers are working.. (Neutron, USB Audio Player Pro, Hiby, Denon, etc)
I think its a Kernel issue.. USB Audio seems to be disabled on it. ?

Some news?
You have found the schematics or other documentation?

Have any of you used a "Type-C (audio) Digital Decoding OFC Cable" like this :

Have any of you used a "Type-C (audio) Digital Decoding OFC Cable" like this :
Link : Original KZ Type-C 0.75mm Digital Decoding OFC Upgrade Cable
Does it really help?
I don't have a type C earphone. So was considering this + a KZ earphone like
https://www.gearbest.com/earphones/pp_009772302190.html

they work perfektly
im using usb audio player pro - https://play.google.com/store/apps/details?id=com.extreamsd.usbaudioplayerpro
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have you looked at the kz zsr 3 ways they are awesome to
Sent from my Mi A2 using Tapatalk

xda2014 said:
Link : Original KZ Type-C 0.75mm Digital Decoding OFC Upgrade Cable
Does it really help?
I don't have a type C earphone. So was considering this + a KZ earphone like
https://www.gearbest.com/earphones/pp_009772302190.html
Click to expand...
Click to collapse
I don't have a type C earphone. So was considering this + a KZ earphone like
https://www.gearbest.com/earphones/pp_009772302190.html[/QUOTE]
I use this one: https://www.soundphilereview.com/reviews/venture-electronics-odyssey-review-2833/
Venture Odyssey. Very cheap (approx. 10€ + transport in Aliexpress). I'm very happy. The sound is very good. The volume is enough for me. It includes a OTG connector so you can use it on your PC. The DAC is better than the internal A2 DAC, and also better than most PCs.
I'm sure that any USB-c DAC improves the sound of our A2 very much.
Best regards

I decided to skip the A2 after reading the forums here.
But :
https://www.head-fi.org/threads/ve-...pressions-thread.886989/page-15#post-14739702
I don't know if anyone has mentioned this yet, but the DAC in the odyssey appears to be a Realtek ALC298, which is a 13 year old USB2.0 16bit 48khz dac (datasheet talks about 192khz support, but I'm not smart enough to understand the datasheet 100%). Windows lists the Hardware ID as "USB\VID_0BDA&PID_4040&REV_0000&MI_00" which returns the ALC298 on google. I'm not confident in this being correct however, since it's a generic driver, and the hardware ID may not be correct.
Click to expand...
Click to collapse
The current fave at Head Fi is this :
https://www.head-fi.org/threads/hidizs-sonata-hd-dac-cable-new-tiny-and-mighty-dac-amp.880478/unread

@SpuTniC_23 @alejandro.pastrana
Does a Type C dac/amp use a lot of battery power?

nope it doesnt use that much it also depend on the resistance of the headphone and how loud - the right slider is the volume any louder and youu will ruin your ears
Sent from my Mi A2 using Tapatalk

I am using letv cdla type c earphones which are giving osm sounds and at night they glow in Orange colour

xda2014 said:
Link : Original KZ Type-C 0.75mm Digital Decoding OFC Upgrade Cable
Does it really help?
I don't have a type C earphone. So was considering this + a KZ earphone like
https://www.gearbest.com/earphones/pp_009772302190.html
Click to expand...
Click to collapse
I made a usb c headphone by using a broken type c to 3.5mm converter (with the usb part , pcb intact with Realtek DAC ship) and a broken set of earphones and assembled to solder them together. It's working like a charm with a very good audio, calling as well as good enough noise cancellation through the mic.

Audio Latency Problem,

I have been trying a few audio latency (ms) apps and i'm getting around 150-200 ms. Which makes Android phones in general unusable when using apps for music creation or timing or rhythm based games.
Is there any way i can root it and fix this using a different codec or driver?
Will this be improved in Android Q?
iPhones for example usually has a latency (ms) of between 8 and 22 ms.
Any news on this or fixes or something i can do myself?

Are you actually using YouTube, Netflix Hulu, or others and see the latency? I see no latency in any videos or the few games I play. I'm also using wireless Bullets.

Where did you get that high numbers?
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I get it when connected to the stereo in my car via Bluetooth and play YouTube content.

hpsauce37 said:
I get it when connected to the stereo in my car via Bluetooth and play YouTube content.
Click to expand...
Click to collapse
Bluetooth has notoriously high latency. If it's not using AptX low latency, it's going to be in the 100-200's
Here's a receiver transmitter combo you can put in your car.
https://www.amazon.com/Avantree-Blu...w+latency&qid=1560636526&s=electronics&sr=1-4

dubt17 said:
Bluetooth has notoriously high latency. If it's not using AptX low latency, it's going to be in the 100-200's
Here's a receiver transmitter combo you can put in your car.
https://www.amazon.com/Avantree-Blu...w+latency&qid=1560636526&s=electronics&sr=1-4
Click to expand...
Click to collapse
While this is typically true, I have had devices when using an iPhone connected via Bluetooth that have seemingly no latency.

For years iOS has always had better latency than Android. It is exactly why Android doesn't have as much music creation apps or rhythm games as iOS.
Even a Google search of "iOS vs Android audio latency" backs this up with tons of articles, tests, and reports about it.

You can improve the latency in developers option as well. Use the codec that matches your headphones or device. It by default uses a generic codec compatible with most devices. Also you could change the sample rate.

Version of bt
I'm really sad about that all you guys forget there is 2 device if you speak about Bluetooth connection. So useless ur OnePlus have bt 5.0 what can have 8 Ms latency if u use an old crappy Chinese headphones with bt 2.0 . For example my headphones have almost zero latency till in my 2012 Peugeot the music is 5 sec late !

Question HI-RES Audio 24 Bit

Hello,
When listening to music, my 24 bit Flac audio files are played down to 16 bits. This is the case with bluetooth headset, wired headset, and its own speaker. I tried many music players. (Samsung music, poweramp, jetaudio etc.) When I look at the developer options, the 24 Bit feature appears to be passive.
I am waiting for your help in this matter. I bought this phone because it has this feature. Otherwise I would buy Mi 11 lite. I hope I will not regret it.

This seems yo be the case with me too.
I would suggest not using Bluetooth as it cannot play hi-res files. Over aux however, I use Poweramp and changed the setting to hi-res output. Even so,my 24 bit FLAC files get downsampled to 16bit. The A52 as far as I know doesn't have a dedicated dac like LG phones used to. Since there isn't any information on samsung website. Qualcomm does mention that 720g comes with support.
An external DAC would work, but that inferres lugging around another piece of tech in your already bulky pocket.
Any help would be great!
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Any new info on this matter? Im thinking of getting this phone and audio is a really important subject to me.
Does poweramp support hd playback on this device or is a external DAC required?

Bt isn't bandwidth capable of supporting 24 bit throughput.
UHQ Upscaler must be enable for hi res output via the C port. That toggle is found in Sound Assistant if you're using it and in Settings.

spannerwindalayer said:
Any new info on this matter? Im thinking of getting this phone and audio is a really important subject to me.
Does poweramp support hd playback on this device or is a external DAC required?
Click to expand...
Click to collapse
This post is a bit old but may help for people searching for Playback of High Resolution Audio.
I am using a FiiO BRT5 with LDAC Bluetooth Codec with Samsung Note10. Its has the highest throw power in wireless high resolution Audio.
Incase of any other brand of mobile phone or bluetooth headphones or amp, make sure ot supports LDAC on both end, LDAC was proprietary of Sony but its now supported by Android as well.

I saw something about Hi-Res audio being only played through the USB C port on USB C earphones and headsets? I think RayOS enabled it on the 3.5mm port too but I might be wrong.

Esim40 said:
This post is a bit old but may help for people searching for Playback of High Resolution Audio.
I am using a FiiO BRT5 with LDAC Bluetooth Codec with Samsung Note10. Its has the highest throw power in wireless high resolution Audio.
Incase of any other brand of mobile phone or bluetooth headphones or amp, make sure ot supports LDAC on both end, LDAC was proprietary of Sony but its now supported by Android as well.
Click to expand...
Click to collapse
In the end i got the phone, and yes, it tells me it's playing at 24 bit/192khz (using hi-res output, it can go further but i dont trust if it's really going that far and anything over 192khz it lowers the volume.)

Question Bluetooth audio delay and greyed out BT codec options

Hi,
In my car BT is always delayed. Headphones - ok.
The only advice I found - experiment with different codecs.
But all of them are greyed in Developer options.
Can you change bt codec in your S22 Ultras?
Any other way to solve delay problems?
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PS: don't blame my car the phone is the problem

If these options are greyed out...it means that the device (your car) doesn't support these codes. Unfortunately...we have to blame the car.
If you can give us more information about the car...and the stereo...maybe we can get more information...but looking at the greyed out options...this system only supports SBC...the minimum bluetooth requirement.

What do you mean by "delay"? Is there latency happening somewhere?
Greyed out codec options means the connected device (in this case, your car's head unit) doesn't support that codec.
Some codecs, like aptX and LDAC, support things like higher bandwidth, but your source signal (i.e., from your phone) needs to be equally good or better (think FLAC files or other lossless audio) for the benefits of of a more modern BT codec to be realized. It's like judging all music through laptop speakers (or our S22U speakers lol), there's a weak link in the chain before it ever reaches your ear.
If I had to guess I would speculate that the underlying cause of whatever delay you're experiencing is due to something else other than BT codecs. But without more info, hard to say.

It's the car. I have the same latency issue when watching videos while playing the audio through my car's BT system.

pjaysnowden said:
If these options are greyed out...it means that the device (your car) doesn't support these codes. Unfortunately...we have to blame the car.
If you can give us more information about the car...and the stereo...maybe we can get more information...but looking at the greyed out options...this system only supports SBC...the minimum bluetooth requirement.
Click to expand...
Click to collapse
Those are greyed out even when my phone is not connected to my car.
You can see in the screenshot that there's no BT connection.
So it's the phone.. not the car. Car is sleeping in the parking lot
Is your BT codec option selection active or not?

Khiraji said:
What do you mean by "delay"? Is there latency happening somewhere?
Greyed out codec options means the connected device (in this case, your car's head unit) doesn't support that codec.
Some codecs, like aptX and LDAC, support things like higher bandwidth, but your source signal (i.e., from your phone) needs to be equally good or better (think FLAC files or other lossless audio) for the benefits of of a more modern BT codec to be realized. It's like judging all music through laptop speakers (or our S22U speakers lol), there's a weak link in the chain before it ever reaches your ear.
If I had to guess I would speculate that the underlying cause of whatever delay you're experiencing is due to something else other than BT codecs. But without more info, hard to say.
Click to expand...
Click to collapse
Codec selection options are not available even when my phone is not connected to my car or any other BT speaker.
Please check BT codec selection in Developer options. Can you change the codec?

bat0nas said:
Those are greyed out even when my phone is not connected to my car.
You can see in the screenshot that there's no BT connection.
So it's the phone.. not the car. Car is sleeping in the parking lot
Is your BT codec option selection active or not?
Click to expand...
Click to collapse
Yes...this is also normal. You can't select a codec until it is connected to a device.
They will all be greyed out...until you connect...and then, whichever codecs the Bluetooth device can decode with light up.
But you know best.....