i need help for making a DAC for better sound quality

Thread Starter

ducher

Joined May 17, 2017
47
Hallo everyone,
I'm working on a DAC (digital to analog converter) I want to have a USB input and a headphone-jack output and that's it.
it need to be powerd by the USB. this is my overal plan:
[PC] --USB--> [MCU/DSP] --I2S--> [DAC] --Analog/Raw-->[Gain/Filter] --Analog/Line-Level--> [Power Amp]--Analog/Phone-Level--> [Headphone]

I have found schematics online (see file) I want to make my own design with the schematics i found. but i don't understand it completely.
Can someone explain me how it works. I'm a student that's why i'm not so good at it yet :p
Thank you so much for helping me out!!
 

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GopherT

Joined Nov 23, 2012
8,012
Hallo everyone,
I'm working on a DAC (digital to analog converter) I want to have a USB input and a headphone-jack output and that's it.
it need to be powerd by the USB. this is my overal plan:
[PC] --USB--> [MCU/DSP] --I2S--> [DAC] --Analog/Raw-->[Gain/Filter] --Analog/Line-Level--> [Power Amp]--Analog/Phone-Level--> [Headphone]

I have found schematics online (see file) I want to make my own design with the schematics i found. but i don't understand it completely.
Can someone explain me how it works. I'm a student that's why i'm not so good at it yet :p
Thank you so much for helping me out!!

What part don't you understand?
 

Thread Starter

ducher

Joined May 17, 2017
47
is the signal amplefied in this circuit or do i need an external amplefier?
the OPA1622 (sheet number 9) has 11 connection points in this schematic, but when i check the datasheet I see only 10 connection points.
in sheet number one you can find the whole circuit, I don't understand the part with the audio-xo, how it's connected.
in sheet number 2 you can find the audioprocessor, the U81 is connected to it and requiers SPI flash. do i need to program this or is this already done when i buy those chips.

Hope you can help me out, i will really appreciat that.
(sorry for the bad english)

btw thanks for responding on my post
 

Sensacell

Joined Jun 19, 2012
2,598
Do you have the source code for this thing?

Although it may seem like a garden-variety USB device, it's actually a very difficult project, unless you have have high-level design, development and troubleshooting experience. There are a million reasons why it won't work right the first time, are you up to the task?

Very few "projects from the internet" actually work, most are incomplete, or poorly designed.

Not trying to be a wet blanket here, just providing some perspective.
 

Thread Starter

ducher

Joined May 17, 2017
47
Do you have the source code for this thing?

Although it may seem like a garden-variety USB device, it's actually a very difficult project, unless you have have high-level design, development and troubleshooting experience. There are a million reasons why it won't work right the first time, are you up to the task?

Very few "projects from the internet" actually work, most are incomplete, or poorly designed.

Not trying to be a wet blanket here, just providing some perspective.
Maybe your right, but i have the gerber files, and the company where i'm a intern will make the PCB for me. so I only need to solder the components on the right place. But I do not only want to make it, i'm trying to understand the circuit so i can learn from it and maybe design my own pcb with the exact same circuit :)

Do you know the questions i asked above? it would realy help me
 

GopherT

Joined Nov 23, 2012
8,012
Maybe your right, but i have the gerber files, and the company where i'm a intern will make the PCB for me. so I only need to solder the components on the right place. But I do not only want to make it, i'm trying to understand the circuit so i can learn from it and maybe design my own pcb with the exact same circuit :)

Do you know the questions i asked above? it would realy help me

It sounds like you have the hardware worked out but there is software code that must be loaded into the microcontroller. Do you have the code?
 

philba

Joined Aug 17, 2017
960
maybe not if you help me out
You are clearly starting at 0. You'll need to learn so much to get to where you want to be. Maybe if some kind soul did it all for you...

If you want to do it, start by learning microcontroller programming. Arduinos are pretty easy to get started with and there are lots of tutorials on them. You may be wanting a DAC but that's only a tiny piece of what you have described. Once you understand programming micros, take a look at the Teensy 3.2 and the Audio board that goes with it. That can do all of what you want.
 

Thread Starter

ducher

Joined May 17, 2017
47
It sounds like you have the hardware worked out but there is software code that must be loaded into the microcontroller. Do you have the code?
Do you know a cheap SPI flash programmer for usb.
do you know the code for this project by chance ? :)

I guesse 706-1334-ND is the part i need to program with SPI flahs code, is that correct
do you maybe know a chip which is already programmed with this code,
(this part is connected to the audio processor with QSPI_NSS, QSPI_SCK, QSPI_D0 QSPI_D1, QSPI_D2, QSPI_D3)

thanks already
 
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