DC-1 tear down at AudioScienceReview. Questions

[jinjuku]

Amir did a tear down of the DC-1 and based on that a few questions cropped up:

1. The unit is using a 3 prong IEC for power but there is no ground lug connection
2. The unit doesn't appear to be double insulted
3. What is the protection mechanism in place from taking a shock off the chassis?

[garbulky]

Feb 5, 2018 17:02:51 GMT -5 jinjuku said:

Amir did a tear down of the DC-1 and based on that a few questions cropped up:

1. The unit is using a 3 prong IEC for power but there is no ground lug connection
2. The unit doesn't appear to be double insulted
3. What is the protection mechanism in place from taking a shock off the chassis?

1. All the better to shock you with its sound quality!
2. This is true. It only insults you one time. But no more.
3. It is suggested you leave the shock on the chassis.

Sorry as you can see I have no idea as to the correct response for these questions!

[brutiarti]

Wow, that teardown was really shocking.

[garbulky]

I appreciate the teardown. He was pretty thorough. But even the things he said was "bad" was honestly not bad at all. We are talking about very low distortion figures below a 100 db. Also we have no idea the test conditions, what kind of power it was getting etc.
That thing about the power cable being compressed, yeah not ideal, but nobody's losing sleep over it.

[Casey Leedom]

Here's the reference to the Audio Science DC-1 Tear Down. Was that unit built in the U.S. or China?

Casey

[pknaz]

Nifty tear down, I wonder how many of his complaints have real world implications that would be, or have been, noticeable to the user without said tear down.

[chicagorspec]

I'm no expert but that seems a long way from something to be proud of.

[Gary Cook]

I am not aware of the US standards and conventions, but from an Australian perspective;

1. The unit is using a 3 prong IEC for power but there is no ground lug connection

Quite common, especially with audio equipment where it helps avoid ground loop hum. A cost saving exercise could be to provide a power cord without an earth pin, but it's hardly an issue.

2. The unit doesn't appear to be double insulted

Not necessary provided it has been designed such that the active wire can not touch the casing. As a result, the casing cannot give an electric shock, even if the wires inside become loose.

3. What is the protection mechanism in place from taking a shock off the chassis?

Refer #2 above.


In summary, no big deal, in fact not a deal of any size.


Cheers
Gary

[chicagorspec]

Maybe it's just me, but I'd be interested in a "rebuttal" of sorts from Emo. @keithl?

[socketman]

I find a 3 prong cord an odd choice but i own all kinds of things that have only 2 prongs. I most certainly would not take the DC-1 into the tub so i feel confident i will not be shocked by it. Not sure what happens in other peoples houses but my stereo equipment sits on a rack and doesnt move and my grand kids dont play with it when they are over. I have endured some pretty hideous ground loop hum in one older house and i had to use a ground lift to cure it so yeah what ever.

[chicagorspec]

In my reading of this teardown, tossing aside the ground issue is far from the end of the story.

When the DC-1 came out, at $699 briefly before the reduction to its steady-state $499, there was a lot of discussion from Emo that this product was groundbreaking at its price for construction and sound quality. This teardown, right or wrong (I'm making no judgments, just hoping to hear Emo's side), makes statements about 1) Poor design re: clearance for the AC wiring, which would be easily rectified with a simple design change (and is a head scratcher to me as an engineer as to why it ended up this way after prototyping, as the solution is right in front of you), 2) Very sloppy and overly-glue-centric assembly, 3) Cheap, low-quality caps, exacerbated by proximity to the heatsink (and this product, which I own, does run HOT), among other things.

I don't know if there's been no response due to Emo and KeithL simply having not seen this, or if the silence is telling and they're simply hoping this falls far enough down the board that not very many take note. Many of the thoughts pointed out in the teardown might be things Emo would have a good response to, but with nothing but silence it's hard to feel confident about that. Emotiva, what say ye?

[mgbpuff]

First of all this was a 'USED' unit. Perhaps it had been worked on. Perhaps the bad soldering was the result of a repair. Class II equipment does not have to have a dedicated ground. The so called pinching of a wire is not a pinching at all, just a well insulated wire touching a non conductive edge of a PC board (come on people!). Cheap caps, well most DACs of this caliber of performance cost many times more - it's nice to be critical if you ignore costs. I would question Arim's credentials given the uninformed opinions he expresses.

[brutiarti]

There is a lot of nitpicking on the teardown, but cheap capacitors are always a downer

[mgbpuff]

Feb 6, 2018 11:31:49 GMT -5 brutiarti said:

There is a lot of nitpicking on the teardown, but cheap capacitors are always a downer

only if they fail

[chicagorspec]

This seems like a perfectly appropriate opportunity for a "Manufacturers Response", and silence speaks volumes in my mind. Expecting an Emotiva response discrediting this teardown and its findings, based on Emotiva's "we've raised the bar" intro for this product, seems to be viewed as pissing in the kool-aid. Hmm.

[novisnick]

Without having one drop of EmoBlue today, I would slow down withall the “wheres the manufacturers rebuttal? This thread is only 18 hours old, I mean,,,,really??,,,,, 

Surely you would like a few minutes to craft such a statement, chat with your peeps and such.

Im not being a fanboy here, just want to be fair minded,  Wait and see what happns, have a little patience, PLEASE🙏

I dont think thats too much to ask.



respectfully,

novisnick 

[chicagorspec]

Feb 6, 2018 12:01:14 GMT -5 novisnick said:

Without having one drop of EmoBlue today, I would slow down withall the “wheres the manufacturers rebuttal? This thread is only 18 hours old, I mean,,,,really??,,,,, 

Surely you would like a few minutes to craft such a statement, chat with your peeps and such.

Im not being a fanboy here, just want to be fair minded,  Wait and see what happns, have a little patience, PLEASE🙏

I dont think thats too much to ask.



respectfully,

novisnick 

On the other hand, KeithL never seems to be too short of time to write veritable tomes on the nuances of theory and execution concerning some obscure issue raised on this forum that one person is trying to implement in his basement. One of the things that I've always admired about Emotiva is its willingness to call a spade a spade, Dan's swashbuckling "Hey guys, here's the deal..." approach. If the findings of this teardown are either 1) invalid, or 2) valid, but irrelevant, saying so would speak volumes. And not saying so does the same, for me.

[novisnick]

Feb 6, 2018 12:22:22 GMT -5 chicagorspec said:

Feb 6, 2018 12:01:14 GMT -5 novisnick said:

Without having one drop of EmoBlue today, I would slow down withall the “wheres the manufacturers rebuttal? This thread is only 18 hours old, I mean,,,,really??,,,,, 

Surely you would like a few minutes to craft such a statement, chat with your peeps and such.

Im not being a fanboy here, just want to be fair minded,  Wait and see what happns, have a little patience, PLEASE🙏

I dont think thats too much to ask.



respectfully,

novisnick 

On the other hand, KeithL never seems to be too short of time to write veritable tomes on the nuances of theory and execution concerning some obscure issue raised on this forum that one person is trying to implement in his basement. One of the things that I've always admired about Emotiva is its willingness to call a spade a spade, Dan's swashbuckling "Hey guys, here's the deal..." approach. If the findings of this teardown are either 1) invalid, or 2) valid, but irrelevant, saying so would speak volumes. And not saying so does the same, for me.

I agree, especially with the “Damn the torpedoes attitude” but this rebuttal would require the owners input and not only the input of their most knowledgeable guru.

Emotiva built it, (DC-1) they will come. 😁

[mgbpuff]

I would think that a blog that does a tear down and critique of a used unit of unknown history is 1)very unprofessional, and 2)very subject to a being sued for unsubstantiated claims Pay for a new one, tear it down, and see if these criticisms hold up. Yes, it will cost you money and you will lose your warranty, but, hey, if you want to be the next Consumer Reports, you're going to have to have some strong financial backings.

[garbulky]

Hold on the AC wire slightly touching the board? That's not an issue. Come on. I really don't see the issues. The performance even on those tests were pretty fantastic. Cheap caps? Well does it sound bad or does it sound amazing? Then who the heck cares? "Overly glued?" Eh? So?

I've heard very expensive DACs - one that cost a few grand. Some of the DACs I've heard did some things a bit better than the DC-1. But when you take the entire sound in to account, I decided I still hadn't heard anything I preferred over the DC-1 and nor something I would upgrade over it. WHenever I switched back, I remained happy with my DC-1 which really does produce some excellent sound - especially in a fully balanced setup.

Not saying that there's not better. But for a $500 DAC that's pretty darn spiffy.
I didn't carefulyl read it but one thing of interest is that the channel tracking at low volumes may not be as precise as claimed. I thought the resistor ladder was supposed to be within 0.5 db of each other in channel matching.

How about some real issues that actually affect the sound quality?