Hi guys.
I'm going to make an PCB for ES9038 DAC in near future.
So it would be nice to know what kind of feature are you looking in that kind of DAC.
I will try to share what was done already in schematic, but it would be great to hear your feedback!
So let's begin :
1) Power supply for whole ES9038 chip has been build with LT3042 chips, they are powering everything related to that chip (right and left channel are powered via dedicated regulator),
1A) LT3042 are MSOP type for easier soldering,
2) clock footprint designed for CCHD-575-100 (or any other 5x7mm clock),
2A) optional u.FL connector for ext. MCLK (selectable via simple SMD jumper),
2B) you can use cLOAD and rISO for clock if you want/need,
3) Most common input types:
- isolated coaxial,
- optical,
- I2S (via u.FL and RJ45/HDMI),
- USB footprint for Amanero.
3A) I2S selector based on 74AC11257 chips,
3B) second 74AC11257 will be optional if you don't want/need to use u.FL I2S input,
3C) ability to feed I2S signal via 3 sources (only one I2S signal can be played at the same time),
4) analog stage based on ESS recommended design (there in one litte diffrence I made XLR output buffered),
4A) One pair of XLR and RCA output,
4B) cut-off/mute relays on every output (so there will be no transient/pop noise when turning on/off),
4C) XLR "ground" connected to chassis not to signal ground,
5) all GPIO pins from ES9038 are presented and connected to IDC-20 connector (ofc with visual indicator) so they can be used if you want,
7) unused DATA input pins are tied to ground via 0ohm resistor, so they can be used if you really want,
8) Most parts are 0603 size to 1206 (opamps are SO8 package), there is no 0402 SMD parts or other hard to solder parts like DFN/QFN chips without "legs".
TODO (maybe) :
1) I2S buffer for RJ45/HDMI input (I think it's not required for u.FL input due to high cost of cables and lenght of those),
2) AES input, but I'm not sure which option is better, proper ratio transformer, or passive converter?
3) more fancy MCLK selector (instead of simple jumper),
4) analog power supply based on ES9311Q instead of LT3042 for analog 3V3?
5) even more than 4 layers?
6) visual indicator for LT3042 PG feature + simple voltage divider UVLO,
7) I2C and I2S isolators,
8) MCU unit, but in this case I'm looking for your help (I'm not skilled with those stuff).
Board will be designed by me and produced in Poland factory (TSPCB) and it will be available for everyone here
PCB will be made on FR4 4 layer material with proper ground partitioning.
Ground common point will be placed directly below ES9038 chip.
Layers stack up will look like this :
1st L signal
2nd L ground
3rd L power
4th L ground + non critical signals (like GPIO etc.).
If I found some time maybe I will try to make even I2S signal traces equal in lenght
I'm really looking for your feedback
I've got some free time and I really want to build something good for myself and community like you, because I found so much knowledge here, so it's payback time
Cheers guys.
I'm going to make an PCB for ES9038 DAC in near future.
So it would be nice to know what kind of feature are you looking in that kind of DAC.
I will try to share what was done already in schematic, but it would be great to hear your feedback!
So let's begin :
1) Power supply for whole ES9038 chip has been build with LT3042 chips, they are powering everything related to that chip (right and left channel are powered via dedicated regulator),
1A) LT3042 are MSOP type for easier soldering,
2) clock footprint designed for CCHD-575-100 (or any other 5x7mm clock),
2A) optional u.FL connector for ext. MCLK (selectable via simple SMD jumper),
2B) you can use cLOAD and rISO for clock if you want/need,
3) Most common input types:
- isolated coaxial,
- optical,
- I2S (via u.FL and RJ45/HDMI),
- USB footprint for Amanero.
3A) I2S selector based on 74AC11257 chips,
3B) second 74AC11257 will be optional if you don't want/need to use u.FL I2S input,
3C) ability to feed I2S signal via 3 sources (only one I2S signal can be played at the same time),
4) analog stage based on ESS recommended design (there in one litte diffrence I made XLR output buffered),
4A) One pair of XLR and RCA output,
4B) cut-off/mute relays on every output (so there will be no transient/pop noise when turning on/off),
4C) XLR "ground" connected to chassis not to signal ground,
5) all GPIO pins from ES9038 are presented and connected to IDC-20 connector (ofc with visual indicator) so they can be used if you want,
7) unused DATA input pins are tied to ground via 0ohm resistor, so they can be used if you really want,
8) Most parts are 0603 size to 1206 (opamps are SO8 package), there is no 0402 SMD parts or other hard to solder parts like DFN/QFN chips without "legs".
TODO (maybe) :
1) I2S buffer for RJ45/HDMI input (I think it's not required for u.FL input due to high cost of cables and lenght of those),
2) AES input, but I'm not sure which option is better, proper ratio transformer, or passive converter?
3) more fancy MCLK selector (instead of simple jumper),
4) analog power supply based on ES9311Q instead of LT3042 for analog 3V3?
5) even more than 4 layers?
6) visual indicator for LT3042 PG feature + simple voltage divider UVLO,
7) I2C and I2S isolators,
8) MCU unit, but in this case I'm looking for your help (I'm not skilled with those stuff).
Board will be designed by me and produced in Poland factory (TSPCB) and it will be available for everyone here
PCB will be made on FR4 4 layer material with proper ground partitioning.
Ground common point will be placed directly below ES9038 chip.
Layers stack up will look like this :
1st L signal
2nd L ground
3rd L power
4th L ground + non critical signals (like GPIO etc.).
If I found some time maybe I will try to make even I2S signal traces equal in lenght
I'm really looking for your feedback
I've got some free time and I really want to build something good for myself and community like you, because I found so much knowledge here, so it's payback time
Cheers guys.
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