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Discussion Starter · #1 ·
Looking for the most direct route for bit perfect. An older thread on here indicated one would need to use the Raspberry PI 4 and Topping D10 to obtain bit perfect from a phone and another from the head unit. However, my OnePlus 8 Pro running Qualcom Snapdragon 865 with WCD9385 will output through USB-C 192khz/32bit, and my Helix dsp.3s has coax input that will process at 12kz to 96khz/192khz uncompressed digital signals. It seems to me that all I need is a USB-C to Coax direct from the phone. My Pioneer DMH-8600NEX has a USB-C input but only rca and high level outputs. Thus, I think I have to use an external DAC to obtain bit perfect with the Pioneer. What part of my logic is faulty?

I do not want to purchase the bluetooth module for the Helix as it is another $150 to $200. Again, looking for fastest and most inexpensive route to bit perfect.
 

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I would still use the Topping. Not as a DAC but as a "bridge". Usb in coax out and no conversion till the dsp.
 

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Discussion Starter · #3 ·
Thank you for your response. How do you define "bridge" in this circumstance, and why do you think I need one? One issue that concerns me about using only a usb-c to coax is the loss of signal due to the distance from the front of my Tacoma to the dsp behind the backseat. Are you suggesting the Topping to act as a booster for the signal?
 

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By bridge I mean usb in to your choice of coax, toslink, or RCAs. The topping will just allow you to change formats without making a digital to analog conversion. If you go rca out to your dsp there will be a conversion to analog at the topping and then another conversion back to digital at the dsp. Make sense?
 

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Looking for the most direct route for bit perfect. An older thread on here indicated one would need to use the Raspberry PI 4 and Topping D10 to obtain bit perfect from a phone and another from the head unit. However, my OnePlus 8 Pro running Qualcom Snapdragon 865 with WCD9385 will output through USB-C 192khz/32bit, and my Helix dsp.3s has coax input that will process at 12kz to 96khz/192khz uncompressed digital signals. It seems to me that all I need is a USB-C to Coax direct from the phone. My Pioneer DMH-8600NEX has a USB-C input but only rca and high level outputs. Thus, I think I have to use an external DAC to obtain bit perfect with the Pioneer. What part of my logic is faulty?

I do not want to purchase the bluetooth module for the Helix as it is another $150 to $200. Again, looking for fastest and most inexpensive route to bit perfect.
You 100% don’t need a raspberry pi! That’s not for use with a phone at least, I think you misunderstood

and you don’t need a dac either to get coax out… a dac is a digital to analogue converter so it’s the last thing you want

To get bit perfect from android you need usb audio player pro, all android audio is sent through the android audio layer and resampled to 48khz

not good… but UAPP gets around this audio layer by taking control of the driver for usb dacs or usb audio bridges (the topping can do both)

As for signal loss, it’s 4-5m, your worrying about nothing, coax is fine for further than that!

The topping D10s is used frequently and perfect for what you need, it is a dac, but you won’t use it as such, it also takes in usb digital audio signals and can output it as a digital signal via optical or coax… I should add that while coax is in theory a better signal, you are worrying too much… before stressing about getting 192khz signals check the dsp internal sample rate… even with my ultra that is 96khz, so even if you send 192khz to the dsp it’s then resampled down, for me coax sounds very similar to optical and blind I can’t tell them apart and I have a very resolving system

your also misunderstanding the term that’s used… The topping isn’t a ‘booster’, it’s a means of changing a digital signal to another digital signal, simple, that’s it, you don’t need a booster or any other boxes! I would get a usb c charging hub for between the phone and topping so you can charge the phone as you use it, it also allows you to use an extension lead to the dash and use usb sticks for music storage and introduction into the phone system if you wish 👍🏼

Also any Bluetooth method will not be bit perfect, it’s not capable of the bandwidth of a wited
 

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Discussion Starter · #7 ·
Thank you both for your replies. Just installed usb audio player pro. I copied the following part that I referred to above about the Pi 4:

"A bit DIY and a narrow use case, but consider the following:

  • a Raspberry Pi 4 (using Moodeaudio or similar) with USB out to a Topping D10s,
  • then spdif from RPi to a Helix DSP
This will be bit perfect and extremely clean.
- your phone (or Android head unit) controls the RPi, it is just a transport.

With this you can use an Android head unit for navi and phone calls and radio (ideally through an optical out to another D10s, to avoid the typically poor analog audio sections of Android heads). If you aren't a fan of Android Auto, you can avoid it with this setup (and use " real" Google Maps and other any other apps).
The Helix DSP and V amps have a mixer that will source switch between the digital and analog input to handle calls and navigation..
This setup avoids the Android audio driver for anything that matters and is relatively economical (given the flexibility and very high signal quality).
If you can get it, the Alpine UTX-A09 looks interesting as well (has optical out,, should be bit perfect, has a mixer to handle calls and navigation)"
 

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Thank you both for your replies. Just installed usb audio player pro. I copied the following part that I referred to above about the Pi 4:

"A bit DIY and a narrow use case, but consider the following:

  • a Raspberry Pi 4 (using Moodeaudio or similar) with USB out to a Topping D10s,
  • then spdif from RPi to a Helix DSP
This will be bit perfect and extremely clean.
- your phone (or Android head unit) controls the RPi, it is just a transport.

With this you can use an Android head unit for navi and phone calls and radio (ideally through an optical out to another D10s, to avoid the typically poor analog audio sections of Android heads). If you aren't a fan of Android Auto, you can avoid it with this setup (and use " real" Google Maps and other any other apps).
The Helix DSP and V amps have a mixer that will source switch between the digital and analog input to handle calls and navigation..
This setup avoids the Android audio driver for anything that matters and is relatively economical (given the flexibility and very high signal quality).
If you can get it, the Alpine UTX-A09 looks interesting as well (has optical out,, should be bit perfect, has a mixer to handle calls and navigation)"
Tha phone really, the raspberry pie is streaming the audio via a topping, the phone acts as a controller for it

you don’t need a raspberry pi to get get bit perfect from your phone, what I explained above will do the job just fine, I don’t see the point in adding an extra device in the chain and needing wifi in the vehicle when your phone is very capable of streaming bit perfect
 
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