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Ciúnas Audio ISO DAC Teardown and Failed Review

amirm

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#1
Someone contacted me to offer a Ciúnas Audio ISO DAC for review which he had purchased used from ebay. I said yes. Well, before he could send it to me the unit failed to operate. He asked me if I could see if it is something simple to fix and I said sure. The ISO DAC costs Euro 400 (US $445).

Note 1: the person behind ISO DAC is very active online and goes by the alias of jkeny (John Keny). He used to be a member here when I first started the forum and we banned him after a while. He and I have some history in the past, both with him being my defender and antagonist. So read what you like into my write-up here.

Note 2: In researching the product, I see that he has a new version with supercapacitors instead of battery.

The ideas behind of ISO DAC are to have battery operation, and isolation of sorts with respect to USB bus.

From the outside, there is no telling of what lies within:

Ciúnas USB DAC Teardown and Review.jpg

I have the top open and put the front panel on with just one screw for the picture. It normally comes assembled of course.

To take it apart, you open the front or back panel and then slide out the top panel. Underneath that there is a thin piece of foam that is meant to keep things together. Alas, it did not as the unit I received had both batteries popped out of their holder. They are pushed back in for this picture:

Ciúnas USB DAC Teardown.jpg


The two little rectangular modules in the front are the chargers (and hopefully) battery management system for the two Lithium cells. They are unfortunately glued to the case so hard to remove and replace them. Tiny wires go back and forth between it and the batteries. I see no obvious fusing. Given how much current these lithium cells can generate together with their very low internal impedance, I like to see plenty of safeguards against shorts. I did not see any. Those tiny wires could get pinched in assembly and later short out.

I pulled out the blue USB cable that normally goes to the back and was surprised to see that yellow wire that is stripped but going nowhere.

Then we get into jungle of PC boards on the right. ON the bottom there is a USB hub that I suspect is pulled out of a retail product and glued to the sides or something. Other PCBs then are haphazardly stuck on top of it.

One of the tenants of "high-end" audio is heroic attempt at keeping noise and interference low. Can't imagine any way or shape that you can put bare PCB stack together with such goal in mind. The opposite is likely true with higher noise as it interference bleeds from one module to another.

Exacerbating the situation are the way the output signals are wired. The red, yellow and black wires conduct these signals. As you see, they are just going every which way. No shielding. No twisting. No symmetry between left and right channel. Just an amateur soldering of wires that come in an electronics hobby kit.

Zooming in from the back we see more issues:

Ciúnas-USB-DAC-Teardown-Board-Stack.jpg


Notice the board below the USB hub. It is just floating in there with the solder connections almost touching the bottom of the case.

You can also see how the boards don't fit the dimensions of the case and are not int he proper slots on the sides.

Let's focus back on the soldering job:

Ciúnas USB DAC Teardown Zoom.jpg


Come on. Really? You couldn't build your own custom PCB for that one IC on it so that you don't have to build such a rat's nest with solder and bare wires everywhere?

And why not route the wires better? Crisscrossing the PCB means that if the insulation of the wires is compromised, you get a short. Have wires soldered from the side to where they need to go. Keep things neat with wires that are the right length and no more.

Why oh why?
Everything I have talked about impacts the buyer of the product. But I also have a message for John. Why on earth do you get into this kind of business? I can see him sitting nights and weekends after his day job cutting wires, soldering, gluing all the mess together. And then start on another. This can't be fun whatsoever. And at US $447 a money loser when you take into account your own time. A few hours of consulting after the hours would make him more money than this kind of thing ever will. Don't confuse your hobby with a business. Best advice I ever read was: "the best way to ruin a good hobby is to turn it into a business!"

The temptation is so high for some audiophiles to get into business of audio hardware. Any kind of hardware business is tough. What John is doing here is even tougher. Instead of listening to some great music, he is reading this review and steaming. Why do you get yourself in such a place?

If you are going to do it, then doing it properly. Pay someone to design a PCB for you and put everything properly on it. Use a much larger case so that you don't have to cram things together. Here is an example of Topping product:



No wires. Nothing to short out. No sitting there taking in solder fumes at night. People who buy your product are not that price sensitive. Raise the price to US $999 and do it properly. Give people something they can be proud of if they ever open it. As it is, I see that there is not one single picture of what is inside ISO DAC. I imagine even John is not daring enough to show it.

If you don't think you can sell enough to justify such an investment then don't get into this business. Your competitor, Uptone invests in custom design and PCBs. You should figure out how to have their scale to do the same.

Of course, all of this assumes that there is merit to such designs. There isn't as we have seen from countless DACs that are exceptionally quiet and low distortion.

Conclusions
We don't know the provenance of this ISO DAC. Maybe it is a prototype and production versions are not this way. In that sense, hopefully someone will take the top off and post the pictures. Otherwise, if they are all like this one, this is a very sad picture, pun intended. The design is unsafe, unreliable and likely not performant. My head is down on behalf the audio industry to see such poor execution.

Let's cross fingers that the new supercapacitor version is better....

--------
As always, questions, comments, corrections, etc. are welcome.

Have go and dig some ditches. What for? The run electrical wires to out shed. I am too frugal to pay someone else to do it. Meanwhile, reviews don't get done while I do that. If you want me to instead have someone else do it, donate some money for heaven's sake. I may still do it myself and pocket the donation for something fun. But surely it will make you feel good that you didn't contribute to me slaving after some ditch! As such, I appreciate your generous donation using : https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 
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#6
Let's hope it's a prototype or the previous owner did some modding... Pity it doesn't work, the results would be interesting.
 
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#8
hahaha. reminds me of a Dynaco PAT4 pre-amp that I owned back in the 70's. Got it real cheap. It worked ok.
I opened the case and realized that I owned a piece of wire-rat's-nest-performance-art. Held my breath and screwed the cover back on and never looked at it again!

that was home built by someone willing to stuff a *lot* of wire in and do a *lot* of poor soldering.
 

amirm

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#12
Is the black DAC PCB from eBay, or is it "borrowed" from another product?
That board is the AMANERO Combo 384 USB interface:

The one in there is black so maybe a different revision. Either way, these are off-the-shelf boards you can buy.
 

amirm

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#17
Clearly this isn't good. However, your review got too personal and was uncomfortable reading. I recommend keeping it professional.
This was the professional version! You should have read what I really wanted to write....
 

Thomas savage

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#19
This was the professional version! You should have read what I really wanted to write....
Digging ditches will be good for you , a honest days work .

Try not to break a nail and remember to moisturise.
 

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