Ciúnas DAC USB DAC Review

[garbulky]

So I went back and searched for JKDAC and landed on your old website in your name. Here is the description of said DAC:

View attachment 38663

It clearly says there are two batteries in there. Yet there is only one battery in this reviewed unit as I have shown:

So it is not the DAC you are talking about. I have asked you for a link to the product description for this unit and you are refusing to provide. How is anyone supposed to know what this product is? It is so bad that it is even confusing you!

Yep that's a pretty bad misstep. The manufacturer needs to know what model it is - especially because the insides are clearly posted!

 

[mkawa]

What he is explaining here is that LiFePO4 batteries hold their voltage at a pretty steady 3.2V during the full discharge cycle until near the end of discharge when their voltage precipitously falls. 2.7V is their recommended minimum voltage & running them right down to 0V & continuing to attempt drawing current will change their chemistry & render them useless. If you don't change their chemistry significantly you still have a battery but not an optimal one
Yes there is a good reason but you need to know something about batteries to understand this

wow. you really do have absolutely no idea what you're doing.

 

[Ciunas Audio1]

Don't get me wrong, your posts are also poor form. You are not answering clear questions on things like grounding, safety and providing what seems to be incorrect reasoning. You also haven't responded to questions about the soldiering or your reasoning about the PCB or about the wire that leads to nowhere. Even if the tone of the forum is negative I think these are reasonable questions.

Indeed reasonable questions that would have been answered if asked reasonably after the initial mistakes & gross flaws in the review had been correctly & adequately addressed but so far no sign of either of these two conditions prevail so I'm afraid this has proven that good faith, a fair hearing & objectivity are not at play here

 

[amirm]

Let's examine. If you had talked with the manufacturer before (and bear with me it's possible that the manufacturer mayhave posted fake info)

How many times do I say I don't do this? I am here as a service for membership and audiophiles. I am not here to go and chase manufacturers. Products are given to me to test by owners, and I test them.

In this case, we not only tested one, but two products. I am paying for shipping back of both of them. I have gone out of my way and has the membership to get to the bottom of what these devices look like. It is remarkable that you ask for more.

You may have found
That it could be run on a battery ("supposedly" providing better reuslts).

You mean against the very manual I am reading in front of me? And in absence of any documentation from John no matter how many times I have asked? Really? I was to damage this unit by draining it to zero by accident just because he may say so?

The correct manual for the model. (The user may have printed out a different manual as he himself was not aware of what model it was.)

And that is my fault? That he doesn't even label his devices?

The power supply may have caused an issue - and you'd have found out that the manufacturer does not provide a power supply. And then you could point out that the manufacturer refuses to supply appropriate details on a "adequately clean" power supply.

I have asked John repeatedly what power supply comes with it and he has refused to answer. So asking in advance would have done me no good.

Some feedback as to his layout and refusal to use a PCB.

And his fingers are broken to provide that answer here and now? And what about me? I am supposed to become stupid and not know after decades in this business that there was merit to this monstrosity of a build?

And more importantly - a working unit - which you could compare to the broken one giving more data.

I have a working unit. This is how the owner has been using it. And the documentation clearly says it should be used with the thing plugged in. And that the sound is the same either way.

I repeat: if there was the worse time to come to the defense of yet another audio manufacturer, this is NOT it. You are making this whole thing worse for him, not better.

So once again, think whose interest you are protecting.

 

[Ciunas Audio1]

More FUD - I don't use LiPo batteries
Is this continual misinformation & propaganda going to continue?

 

[Ciunas Audio1]

wow. you really do have absolutely no idea what you're doing.

You could try dealing with some substance in your reply rather than just trying a snide opinion
Do you have any contrary information to what I'm saying? If so, please present it.

 

[Blumlein 88]

And you don't see the irony in what you say "No point in you posting if you have nothing more to add but continuous repetition"....."show the innards"

You didn't answer my question about whether you measure your products or not. If you have issues with Amir's results, can you show us the results of your own testing? Or do you only measure by ear?

 

[Wombat]

Give @Ciunas Audio I the last word so he can withdraw.

The threads will stand as testimony.

 

[Ciunas Audio1]

How many times do I say I don't do this? I am here as a service for membership and audiophiles. I am not here to go and chase manufacturers. Products are given to me to test by owners, and I test them.

In this case, we not only tested one, but two products. I am paying for shipping back of both of them. I have gone out of my way and has the membership to get to the bottom of what these devices look like. It is remarkable that you ask for more.

You mean against the very manual I am reading in front of me?..

You were already told that was the wrong manual

And in absence of any documentation from John no matter how many times I have asked? Really?

You don't ask for these things in a manner that makes me conducive to providing them - tell me why I should bother given your attitude & obvious bias? .

I was to damage this unit by draining it to zero by accident just because he may say so?.

I already gave you assurances that I would fix any battery that died & pay for any postage to & from

And that is my fault? That he doesn't even label his devices?

The buyer should have established what he was buying from the seller & if different returned it

I have asked John repeatedly what power supply comes with it and he has refused to answer.

You have been told repeatedly that those DACs were not supplied with a power supply - a USB charging cable was supplied which allowed charging from a USB port or the user could use his own external 5v PS

So asking in advance would have done me no good..

Well it might have done you good if you had bothered to listen to the answers when you were more focused & not enraged on a forum thread

And his fingers are broken to provide that answer here and now?

You have had answers already as per above but you continually are deaf to these answers & prefer the pretence that they have't been given .

And what about me? I am supposed to become stupid and not know after decades in this business that there was merit to this monstrosity of a build?


I have a working unit. This is how the owner has been using it. And the documentation clearly says it should be used with the thing plugged in. And that the sound is the same either way..

And both you & the user are wrong - the battery is dead & you are in deep denial

.

I repeat: if there was the worse time to come to the defense of yet another audio manufacturer, this is NOT it. You are making this whole thing worse for him, not better.

So once again, think whose interest you are protecting.

garbulky, he doesn't like what you are saying. Pity because if he showed the same level of respect & professionalism to me as you do he would have had a different response[/quote][/quote]

 

[mkawa]

if you short a high current lifepo4 cell like an anr26650 you are still going to cause a fire.

if you're not familiar with borderline personality disorder and/or narcissistic personality disorder, this is what it looks like.

 

[digicidal]

if you short a high current lifepo4 cell like an anr26650 you are still going to cause a fire.
if you're not familiar with borderline personality disorder and/or narcissistic personality disorder, this is what it looks like.

I'm pretty sure everyone with a television and at least one news channel knows very well what it looks like...

 

[Xulonn]

Another example of the lack of any care for accuracy in this supposedly objective & scientific review site- this is not a Lithium Ferrous Phosphate (LiFePO4) battery so why post it?

Some attempt at FUD?

Videos deleted wit a note about the fire safety of LFP batteries (although that doesn't negate the dangers of potential massive amperage releases due to shorts which could ignite other flammable components in the case.)

(See, admitting errors isn't that difficult!)

No FUD intended. Surely you are not naive enough to think that everyone participating at this site is an engineer or scientist? like you, I am neither a scientist nor an engineer, and again, like you, I did not do my homework. I simply saw the words "when lithium batteries catch fire" and did not research the details.

But please note that I follow the lead of good science by acknowledging and correcting errors - why are you refusing to do the same?

p.s. The fact that you also refuse to post photos proving that your current DACS are no longer atrocious examples of bad electronics techniques is very telling. I'm guessing that the reason is that your current DACs are at least as bad as your 7-year old ones.

p.p.s. I have a 25 y/o Classé amplifier that I recently purchased. It was tested by the engineer/owner of a New York high-end audio dealer who found it to performing like new. Your replies here indicate that you do not believe that your DACs can preform even adequately after only 7 years? That in itself is a direct admission of poor design and engineering, and/or construction.

 

[amirm]

You were already told that was the wrong manual

As if I believe a thing you say without proper proof and documentation. Which you have failed to provide.

 

[garbulky]

How many times do I say I don't do this? I am here as a service for membership and audiophiles. I am not here to go and chase manufacturers. I have gone out of my way and has the membership to get to the bottom of what these devices look like. It is remarkable that you ask for more.

You don't have to do any of those things - but it would make for stronger reviews. So by what I'm saying is not telling you to waste a lot of time. It's simple as emailing the manufactuer introducing yourself and either pasting your review or simply point out the negatives found and if they have any comments. If they refuse to get back to you then that's on them. If they come moaning about it in the review, then you can always point out that they did not respond. Think how much time did you spend defending yourself on this review and some other manufacturers who got pissed at you? It would have been easier, quicker, just to talk to them and shows your review in a stronger light.

You mean against the very manual I am reading in front of me?

Sure. According to the manufacturer there was no manual provided. The user could have printed out the product manual for the WRONG product - which is what the manufacturer is saying happened. Having said that, it looks like even the manufacturer doesn't know what product it is. So the mind boggles!

And in absence of any documentation from John no matter how many times I have asked? Really? I was to damage this unit by draining it to zero by accident just because he may say so?

If he said so, it is up to you. If you drained it to zero then it would be on the manufacturer because it is his product and his reccomendation. I doubt you would be breaking the unit.

And that is my fault?

Yes. You should know what the product you are reviewing is and you would if you had contacted the manufacturer and he corrected a misconception. Edit: Though apparently you wouldn't even then due to his seeming lack of knowledge on his own product! I have no words....!

That he doesn't even label his devices?

No that's not your fault at all. That's poor practice on the manufacturers part - including that he himself doesn't know what the device he made was as you pointed out.

I have asked John repeatedly what power supply comes with it and he has refused to answer. So asking in advance would have done me no good.

I thought he made clear that it doesn't come with a power supply. But he should then recommend a competent power supply. If you asked him in advance should have him saying "oh that PS is no good. You must use this one. Here let me send it to you." If he doesn't do it, then it's on him when you test him with what you have on hand.

And his fingers are broken to provide that answer here and now?

Not at all. He should provide this information. However he likely won't because he either doesn't know or you've p*ssed him off.

And what about me? I am supposed to become stupid and not know after decades in this business that there was merit to this monstrosity of a build?

Of course not. Point out the flaws you see and I think you did that well though you went overboard (imo) on personal remarks.
I'm just saying Cover all bases - give the manufacturer an email, publish relevant responses. It's not hard. If you don't, you give the manufacturer the impression you are on a smear campaign and then have a lack of feedback from them. I'm not saying you are on a smear campaign just that it's not going to show you in a fair light if you ignore it.

I have a working unit. This is how the owner has been using it. And the documentation clearly says it should be used with the thing plugged in. And that the sound is the same either way.

I apologize I thought I was on the thread with the broken unit!

I repeat: if there was the worse time to come to the defense of yet another audio manufacturer, this is NOT it.

This IS the time. Treat them equally and respectfully. Let the facts sort them out.

You are making this whole thing worse for him, not better.

I'm not trying to make anything better or worse for him. I don't know this manufacturer and he doesn't seem too pleasant and his build quality leaves quite a bit to be desired. I would not buy a DAC from this company or even use one if somebody gave it to me for free.

So once again, think whose interest you are protecting.

I'm not protecting anybody's interest. I'm asking for
1. Better standards of respect and professionalism towards manufacturers of products that are being reviewed. Do not let third party manufacturers come and accuse the manufacturer's of all kinds of things. Do not let the manufacturer be called names. Don't tell the manufacturer they just need to quit or be derogatory. Unnecessary. Point out the flaws and the safety issues as you've done quite well.
- Also an aside, probably not a good idea to review a piece of gear with whom you've admitted that you've had a "history" because it makes people think of bias. But I don't really have a problem with it as long as it is done properly.

2. Contacting the manufacturer before the review - think five minute email. That way you cover your bases against criticism - you gave the manufacturer a chance to respond. I get that you don't want to do it for *reasons* but I mean - it's not that hard and makes for a stronger, fairer review.

 

[amirm]

I thought to loop up the measurements from TI/Bur Brown on the PCM DAC chip used in this device. Like a good company, they provide nice set of measurements including this one:

It is a simple enough measurement so I duplicated it with this DAC. Here are the results with the above scaled and overlaid on top of it:

Below about -80 dB, the Audio Precision APx555 gives up on measuring anything with noise being so high. As levels get stronger than that, then it is able to extract THD+N and we see a graph that is much worse than TI measurements. Noise is much higher. For example, at -60 dB, TI spec for THD+N ratio is = -50 dB. John's box turns in -24 dB! That is an incredible gap.

The trend continues until we get a sudden drop in noise at -18 dB or so. Even then, response is worse than TI reference design.

The overall shape though with the saturation near 0 dBFS pretty much matches TI shape proving that our measurements are correct and representative of the chip.

The PCM1502 or is not particularly good peforming DAC, able to turn in at best around 95 dB of SINAD. So it should have bee easier to design circuits around it to achieve that performance than say, SINAD Of 120 dB. Yet John has managed to mess that up so badly.

Conclusion
The TI reference specifications easily outperform the Ciúnas DAC clearly indicating poor design. The DAC is far noisier than it should be and has data dependent noise modulation which is not good.

Naturally this is what happens when the design is not verified using measurements. Wet thumb was put in the air that it must be good because he followed this or that other audiophile fallacy, while missing the basics.

 

[alex1berg]

Oh dear, Amir scratched the case then


The hyperbole in bold is hard to take seriously - remember there is no mains involved, no DC voltages over 5V

For the reasons already pointed out byJK.

So you want me to ignore the many mistakes in evidence in this deeply flawed set of measurements of a >7 year old broken DAC & the reluctance by Amir to admit to these mistakes or anybody here to admit to this & show any objectivity - ignore all this & provide Amir with a current model in anticipation of an objective & unbiased review & measurements?

How naive do you think I am?

No, just post a photo of one of your current train-wrecks.

 

[Wombat]

Oxymoron: Advising a vested interest that an independent review is to be conducted. That compromises 'arms length'.

 

[amirm]

You don't have to do any of those things - but it would make for stronger reviews.

Again, there is confusion about what we do here. I run a set of tests. Those tests are the data people come here to read. I operate the unit just like the owner does. And I provide the data.

At the bottom of every review there is this line:

I have proven time and time again that I mean that. I am happy to re-run tests. Test new samples, etc. Nothing about contacting the manufacturer makes the work here stronger. If anything, can subject me to being influenced by what they say.

Anyway, this is who we are. And what we do. If you like an alternative, find it and become a patron of them.

 

[Wombat]

@Ciunas Audio1. Operating a small business. Lots to learn here even if certification is not pursued.

https://www.sciqual.com.au/news/three-steps-iso-9001-certification-small-businesses

Disclaimer. Prior to retirement I was an Internationally Certified ISO 9000 Series Lead Auditor for 10 years. In that time I had never seen a product that looks so cobbled together with such poor assembly skills. Stop defending and improve.

By the way, when I was met with waffle, diversion, evasion, etc, after asking for sightings to be explained or statements to be verified, my response was simply "just show me".

Is it too hard?

 

[garbulky]

Nothing about contacting the manufacturer makes the work here stronger.

I have to strongly disagree here. It shows that you cover your bases.
But even better, it provides the reader additional information. The manufacturers, after all, built the product you review. Why not get some feedback. It's one of my favorite parts of a review. You see in to the mind of the manufacturer. I really liked it when I heard from Bruno and it would have been even better if he was actually part of your review. Like "I got that SINAD that low by overcoming this hurdle etc.)

Also the tone of the manufacturers response is very telling. Some manufacturers are just plain jerks and it's obvious in their responses. It tells me to avoid those companies because I know how I would be treated. Also one can tell when a manufacturer is purposefully being vague - a telling sign of their business practices!
Most of the time the end user does not get this exposure so anybody that goes that extra step is always appreciated by me. My friend also does reviews (for home theater hifi). He too contacts the manufacturer and I am always interested in their answers/non-answers they provide.

If anything, can subject me to being influenced by what they say.

Come, now. I find that hard to believe. You are one of the most single minded reviewers I have (had the pleasure) to read.

Anyway, this is who we are. And what we do. If you like an alternative, find it and become a patron of them.

If I didn't think your site was worthwhile or provides interesting reading, I wouldn't be here