DIYing a DAC and comparing with ready made
Sep 1, 2018 at 12:29 PM Thread Starter Post #1 of 7

carlmart

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Some days ago I opened a thread here on assembling a DAC using boards available on ebay or elsewhere.

Got no answers at all, and I wonder what DIY people are doing here.

My believe is that you can use available bloards and assemble a DAC that potentially can compare to the more expensive types.

But of course, to check on that there should have to be people that did it and compared them to ready made units.

Nobody did?
 
Sep 2, 2018 at 8:35 AM Post #2 of 7
Is there anybody there?

I've made a list of a modular DAC, using boards from the same brand: DIYinhk:

DAC:

ES9038PRO XMOS DSD DXD 768kHz USB DAC with Bit-perfect volume control and SPDIF input - DIYINHK

DSD:

Isolated XMOS DSD DXD 384kHz high-quality USB to I2S/DSD PCB with ultralow noise regulator - DIYINHK

Power supply:

0.8uV Ultralow noise DAC power supply regulator 3.3/5/7V 1.5A*x2 - DIYINHK

I2S interface:

FIFO Reclock Jitter Eliminator - DIYINHK

I'm not sure why or what for would I need this:

1.3"OLED and rotary encoder volume control PCB - DIYINHK

No idea how I would select the inputs between DSD, coaxial and optical. That's something I might ask DUYinhk.

Basic bill till now: $230.

I'm planning on a separate box for the transformer, to keep noise low.

This is a very feasible project, with the potential to be a very sophisticated DAC, at a fraction of what somthing comparable on the market might cost.
 
Sep 4, 2018 at 3:59 PM Post #3 of 7
I think we mentioned this in the beginner's section, or maybe I thought better of it before I sent you here. In any event, I don't think it's as easy as you suggest:

1. DAC - what you list is not a DAC. It's a USB communications module intended to feed into a DAC. They supply a couple of free DAC PCBs if you buy this module. Here's one of them:
https://www.diyinhk.com/shop/audio-...2.html#/dac_option-xmos_768k_dac_and_oled_pcb
Note that you have to build it, although the SMD parts are soldered. Further, it's only guaranteed for 16-bit, 192kHz and it will do nothing whatsoever with DSD.

Finally, note that it requires not only 3.3V, but also + and -12VDC. The communications module can use the same 3.3V, but your current requirements in the power supply are building - not to mention that +and- 12VDC requirement, which is complicated.

2. DSD - again, this is not a DAC. It's a higher-quality version of what you thought was a DAC in #1 above. Only, it comes with no free DAC PCB. It also requires 3.3V.

3. Power Supply - this is only the output module and the only voltage you can use from it, based on what you are trying to select above, is the 3.3V output. There is nothing to provide the +and- 12VDC required from your "free" DAC PCB when buying the communications module in item #1. Beyond that, there is nothing whatsoever for a transformer, line voltage or other input to the power regulator output module. It's only an output power supply module and as such, incomplete to work with anything.

4. FIFO Reclock - this is your asynchronous to synchronous clock controller. Note that it immediately reduces the sample rate of your communications module from item #1 to 192kHz. If you look up the link, you'll find a second photo on their website that shows this module as the connecting bridge between a communications module (your first item) and a DAC PCB, depending on what you might select (could be the free one you get from ordering item #1).

Note that nothing is yet powered and you have no solution at all for a transformer/line power or the + and - 12VDC required by a DAC module. I think a lot more study of the DIYINHK website is needed before you spend any money. A lot more money will be required, too, needless to say.

I hope that's not too discouraging. Perhaps further study will reveal a complete solution on the website somewhere, but it's a bit difficult to discern with the language issue that seems to be prevalent on that site.
 
Sep 5, 2018 at 3:57 AM Post #4 of 7
At last someone came by to say hello. I don't find your comments discouraging, even if wrong.

To start with I was a proposing a modular system, which would need some refining and confirmation from DIYinhk that it would work as I was expecting it would

The first thing I selected wrong, which elevates the final budget, was due to my mistake on the main DAC board I selected.

Let's describe what I think we need: a receiver interface stage, which has to deal with USB, optical and coaxial; an i2S interface stage, that's just before the DAC chip itself and allows interface to external digital boards (like DSD); an output stage, usually with opamps, that provide analog audio outputs, balanced and/or balanced.

Besides that you have a power supply stage, that feeds regulated DC in different voltages to the main DAC board and all other stages; and some sort of signal input selector, usually with a screen or LEDs to show up front which and what type the digital signal is on that input.

Before going on, please tell me if you agree on this blocking I described. If you think something is wrong or not clear enough, please do say how it is.
 
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Sep 5, 2018 at 11:06 AM Post #5 of 7
Now I just got a reply from DIYinhk, saying that both DAC boards with ES9018 ES9038 chips only have I2S and SPDIF optical inputs.

That's a major problem for me, as my first option for interface would be mostly coaxial, not optical. And I don't have much access to DSD files yet.

I have another kit to assemble, with an AK4393 DAC, but it's not compatible with DSD boards. It does have coaxial and I2S inputs. Input selection would be using a relay switch

This kit has everything on-board: receiver, DAC, separate supplies, etc.
 
Sep 5, 2018 at 3:30 PM Post #6 of 7
This DIY area is relatively a ghost town these days. DIYAudio.com is a better place to pose your questions.

There are other modular DACs out there if you want to shop around:
Abbas Audio - mostly tube based with some cool old Germanium transistors, based in Ukraine:
ANK (previously Audio Note Kits), based in Canada
Twisted Pear Audio, based in Massachusetts, USA

Don't know much about DIYinHK, you may want to make sure there are other builders out there before leaping in so you know someone could potentially help you troubleshoot a build.
 
Sep 5, 2018 at 4:08 PM Post #7 of 7
Thanks, I already posted these questions in DIYAudio too.

But there you don't get comparisons with commercial units, in order to have an idea on what quality level you achieved.

ANK and Twisted Pear are not exactly cheap on their products.

You are also right that I do need to find other people that bought DIYinhk, to see what audio quality you should expect.

There was a long lasting thread on this forum about the F1 XU208 DSD board, which you have to connect to a compatible DAC board through coaxial or I2S. Several people got that board and told their experience.

But I thought it might be a better idea to assemble boards from the same manufacturer. I never got to know who made that board and if there were compatible boards to connect it to.
 

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