Here are some photos of my project in temporary box. Now only support optical input, but later it will be spdif, usb and Bluetooth I think. 5 separate 3.3Vdc ADM7150 LDO boards feed from 2 separate transformer winding's (3 for digital and 2 for analog), and Jung super reg V2.3 for output I/V and buffer (last picture my home made board) 
sorry for blurred pictures
sorry for blurred pictures Attachments
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I would be more concerned about dry joints on other components. Just from the photo it looks like two capacitors are hardly soldered on one side.
Hi, I looked to my dac and pins are not shorted, but it doesn't make any sense because I looked into datasheet and these pins are: 1- DGND; 2- N.C.
This is a more expensive board, that has been assembled to a higher standard.
Clearly the pins are not designed to be bridged. However, since one of the pins is probably not connected, it won't affect performance. Its just a reflection of the lack of care and attention to detail, that can be expected from these cheap ebay products.
@Naaling my 9028 board does not have a bridge between the 2 pins. One is grounded, the second 740ohm to ground. Have been modding the board, but worked ok beforehand.
@wbytalk you,be used 1.8v power for one pin. My board as standard has 1.3y. Does changing that to 1.8v make a difference. I'm changing the power supplies anyway, so could do either?
@wbytalk you,be used 1.8v power for one pin. My board as standard has 1.3y. Does changing that to 1.8v make a difference. I'm changing the power supplies anyway, so could do either?
Hey thanks. looks good this board! Finally a real symmetric DC power for the op amps and no dc blocker caps in signal path at the outputs. But where is the (master?) clock oszillator?
Maybe i give it a try after my bad experiences with the other cheap es9028 board with sw errors and sudden channel changes etc..
Maybe i give it a try after my bad experiences with the other cheap es9028 board with sw errors and sudden channel changes etc..
Hi Naaling - it definitely is of interest - it seems that there is already an MCU fitted (ST's STM 8S103F3) programmed to allow access to some of the es9028 internal hardware functions (volume etc). By soldering tact switches onto the lands already on the board this seems to allow volume control and other stuff like switching i2s input etc. Just need to work out if the volume can be accessed using something like a Raspberry Pi already running Moode or Rune etc. Thanks Adrian
ES9018K2M I2S ES9018 IIS-32bit 128 256 384K /DSD64 Input Decoding Board | eBay
Amazing and cheap board The original board shows the third harmonic of the 1kHz 0dB at around -87dB. After the buffer was replaced with this one simple schematic with the +/-15V supply :
http://content30-foto.inbox.lv/albums/v/viccc/ES9018K2M/ESbuf.jpg
Now the 1kHz 0dB looks that:
http://content30-foto.inbox.lv/albums/v/viccc/ES9018K2M/1kHz0dB.jpg
1kHz -3dB:
http://content30-foto.inbox.lv/albums/v/viccc/ES9018K2M/1kHz.jpg
The mix of 19kHz -6.1dB and 20kHz -6.1dB:
http://content30-foto.inbox.lv/albums/v/viccc/ES9018K2M/19kHz-20kHz.jpg
All this was played from the wav files 44.1kHz 16 bit under WXP>foobar USB Asio out>E-MU0202>I2S>ES9018K2M
Also the the ES9018K2M runs from the E-MUs crystal oscillator 22.579Mhz.
Victor
Amazing and cheap board
The original board shows the third harmonic of the 1kHz 0dB at around -87dB. After the buffer was replaced with this one simple schematic with the +/-15V supply :http://content30-foto.inbox.lv/albums/v/viccc/ES9018K2M/ESbuf.jpg
Now the 1kHz 0dB looks that:
http://content30-foto.inbox.lv/albums/v/viccc/ES9018K2M/1kHz0dB.jpg
1kHz -3dB:
http://content30-foto.inbox.lv/albums/v/viccc/ES9018K2M/1kHz.jpg
The mix of 19kHz -6.1dB and 20kHz -6.1dB:
http://content30-foto.inbox.lv/albums/v/viccc/ES9018K2M/19kHz-20kHz.jpg
All this was played from the wav files 44.1kHz 16 bit under WXP>foobar USB Asio out>E-MU0202>I2S>ES9018K2M
Also the the ES9018K2M runs from the E-MUs crystal oscillator 22.579Mhz.
Victor
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ES9018K2M I2S ES9018 IIS-32bit 128 256 384K /DSD64 Input Decoding Board | eBay
Amazing and cheap board
http://content30-foto.inbox.lv/albums/v/viccc/ES9018K2M/ESbuf.jpg
Now the 1kHz 0dB looks that:
http://content30-foto.inbox.lv/albums/v/viccc/ES9018K2M/1kHz0dB.jpg
1kHz -3dB:
http://content30-foto.inbox.lv/albums/v/viccc/ES9018K2M/1kHz.jpg
The mix of 19kHz -6.1dB and 20kHz -6.1dB:
http://content30-foto.inbox.lv/albums/v/viccc/ES9018K2M/19kHz-20kHz.jpg
All this was played from the wav files 44.1kHz 16 bit under WXP>foobar USB Asio out>E-MU0202>I2S>ES9018K2M
Also the the ES9018K2M runs from the E-MUs crystal oscillator 22.579Mhz.
Victor
Hello, can you explain how to make measurements like you do? Do I need additional hardware? And that software to use?
DVCC - without changes. AVCC has 3 x 1800uF capacitors in parallel with the onboard tantalum capacitor.
For the spectrum measurements I am using Asus Xonar D2 with the improvements, and the Spectrum Lab software. This is the long story, and if you wish, you can write me PM.Hello, can you explain how to make measurements like you do? Do I need additional hardware? And that software to use?
I have a question to my cheap 9028q2m board (refering to my post #109). I connect this board without MCLK to my Raspi hifiberry DAC + pro i2s output and got the trouble I described before. I repeated this test again today but without any sound and finally even a big "popp" coming out of my speakers. I run an AKM DAC like this (but with MCKL connected) without any trouble since months.
Today I drove the 9028 board parallel to the i2s pins of my DCX2496 DAC input pins and it works perfectly..
Any idea why the 9028 has such problems with the Raspi-set-up? Could it be a matter of signal isolation or ground? Or some deviation in i2s format? The only direct ground connection between Raspi and 9028 board is via the i2s ground line. They have independant PSU.
Thanks!
Today I drove the 9028 board parallel to the i2s pins of my DCX2496 DAC input pins and it works perfectly..
Any idea why the 9028 has such problems with the Raspi-set-up? Could it be a matter of signal isolation or ground? Or some deviation in i2s format? The only direct ground connection between Raspi and 9028 board is via the i2s ground line. They have independant PSU.
Thanks!
hi again. seems I solved my problem with a piece of aluminum film...I realized the signal came back when I touched the i2s wire. Even holding my hand close to the wire could made the signal appear or disappear. Shielding the entire wire solved the problem now. Not sure if it is the bluetooth of the Raspithat disturbed the signal or what made the difference to the dcx but it works now!
And the 9028 sounds great! Even slightly better staging than my AKM and fantastic high frequency resolution. Not only for the price a very good DAC (at least with the mods I did).
And the 9028 sounds great! Even slightly better staging than my AKM and fantastic high frequency resolution. Not only for the price a very good DAC (at least with the mods I did).
