ES9038Q2M Board

Found a problem with the XMOS USB to I2S board that attaches to the SRC as shown in the previous post. Turns out XMOS board has a SPDIF output which I like and want to keep, but they put it where the SRC board is expecting the mute pin to be, and where it would be on an Amanero USB board. Turned out the safe fix as far as the SRC board goes is to swap the two pins on the XMOS board which was done as shown in the pics below.
 

Attachments

  • Straight_1JPG.jpg
    Straight_1JPG.jpg
    582.9 KB · Views: 598
  • Angle.jpg
    Angle.jpg
    238.7 KB · Views: 624
Unfortunately, the only easy way to get a display is to order a board that comes with one. Sorry.

More specifically, it appears to be possible to buy a version 1.07 DAC board without a display, but not a display without a version 1.07 DAC board. So far, only version 1.07 DAC boards have the necessary firmware to drive a display.
 
Interesting they say it works for 1.06 boards. I monitored the I2C bus while the DAC booted and never saw it try to address any device other than the ES9038Q2M. Don't see how a display could work with my particular 1.06 DAC board then?

Also, come to think of it didn't someone report buying a display and found it didn't work with their 1.06 board? Might have been earlier in this thread or another DAC thread here in the forum.

In addition, 1.06 boards don't (or didn't) come with an I2C connector although there are solder pads for one.

Perhaps the most recent 1.06 boards have been shipping with new firmware?
 
Looks like it has more output stage opamps that just one, maybe 2 or 3. That could be enough for possible I/V conversion. Need to see better pics or see one in person to know for sure.
The DAC has one NE5532 on socket. There are more SMD nearby which could be opamp too. Hard to tell what they are and the function. The TPA6120 headphone amp IC is a good feature for the $199 model.

I like the one I got so far. At $80 less and has more room for mod.
ES9038 ES9038Q2M DAC Decoder board Support IIS DSD DOP 384KHz with Amanero USB-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
But I have to bring my own power supply and Apple remote. I should start my update mod soon.
 
So far we have only had a few build reports from people. It sure would be nice if we could collect some information about how far people have gone with modding and what mods that they have tried have helped the most. Don't even know if anybody besides me has done a clock upgrade. Or, if anybody beside me has tried hardware upsampling to go with the other mods (now up to 960kHz hardware upsampling recently)? Maybe people are still waiting for parts to come from China, or maybe this is more of a read it thread more than a do it thread? Don't know.

Like I said before if somebody within reasonably shipping distance has done all the mods except upsampling, I could send a spare SRC4392 board to try out.

Also, what about headphone amps? Is anybody doing anything to make a very low distortion headphone amp. The LME49600 board is only around $32 and only needs some resistors and caps, and a little copper foil to make it actually pretty good. Plugging headphones into one of these Chinese DAC boards we are modding increases distortion quite a bit due to loading on the opamp, and most other external amps people have to listen with aren't especially low distortion. Therefore they don't make really clear how the DAC is performing.
 
Last edited:
Hi Mark,
my clock has arrived now and also smd solder paste such as my new hot air solder station.

I sure would suggest practicing on some scrap boards with that hot air and solder paste, there are some tricks to go along with that.

Also, you may recall although I was prepared to do all that if necessary it didn't turn out to be necessary at all. Chip Quik removed the old clock with a low temperature iron, and the new one was soldered in one pin at a time also with a iron.

However you end up doing it, it will be interesting to see what you think about the new clock's effect on sound quality.
 
I finally got my 9028pro board. It is not a bad board considering all the mods mentioned here is easily done on the board. And Markw4, this ebay DAC board is a 4 layer board! It appears that the designer did look at grounding seriously as well. The only downside is that I need to be careful when desoldering. Proper 3 op amp IV section as well for each channel as well.
I'll think about adding the LTC 6655 voltage reference to my 3042 boards but the AVCC as well as the clock will be powered by separate LT3042s. The low noise LT3042 should help the clock I think. Because of the multiple layers it is more difficult to separate L and R AVCC feeds. Same for L&R feeds for the op amp.
Initially I will just put in a 22uF tantalum as Cset on both my LT3042 because of space restrictions inside the case.
My LT3042s will be preregulated by a 317 reg.
The op amps for the IV section will be fed by my existing Sulzer Power Supply.
Then I might consider upgrading the clock.
All this will be dropped into a case where the transformers will be in a remote case. I already have the case for the DAC which will hold the DAC and power supplies. There will be 4 separate transformers in the end.
Question. Is an external SRC a good option?
After letting the smoke out of my last 9038q2M I need to be very careful this time.
 
Last edited:
Question. Is an external SRC a good option?

As always, if doing everything you can reasonably do to make a good DAC, one of the things is reduce group delay and pre-ringing due to reconstruction filtering as much as possible. Remember, the reason there are so many filte choices is because they are all audible (which is a bad thing that really shouldn't be). Using a minimum phase, slow transition filter will give the least group delay and add no pre-ringing. It will however be very audible without upsampling to move the transition band up into an emplty space above the audio frequency band you are listening to.

If you are still undecided when that is the last thing left to do I can send you my spare one to try. Then you can decide for yourself. Would that be okay?

Aside: Are you saying on your particular board AVCC_L and AVCC_R are connected together? If so, IIRC, PRO chips have maybe four AVCC pins? However many they do have, half are considered Left and the other half Right. If they are all connected together that would not ideal in terms of maintaining good stereo separation. In that case and with a multilayer board the only option might be to lift all the pins for one side or the other, Left or Right, and patch them above board into a separate supply. With some practice on a scrap board you should be able to gain some confidence with the procedure. Please let me know if you would like some tips that might help if you want to play around with giving it a try.
 
Last edited: