I don’t doubt someone enjoyed it and, as I said, I thought the SMSL DACs were just fine, but the D90 III sounded like poo to me. I compared the D90 III directly against the SMSL SU-9 Pro, VWV D1se2 and even a Yamaha RX-A8A. In theory, they should have all sounded exactly alike, but they were only ’similar’ with their own noticeable faults.

No. In theory and practice, you are assured to perceive differences between them! This is the nature of sighted testing where your brain is working differently in such comparisons.

They would sound the same, gosh I can’t believe I have to keep saying this, if you matched levels, conducted the test blind, and repeated. Until you do this, you are going to produce random outcomes. Measurements can never predict what your eyes and brain are doing. Only what your ear will capture. Until you focus the comparison to your ears alone, that is the outcome you are going to get.

I can tell you story after story of thinking two things were different when it turned out to be identical.

On AVS Forum, some post a test of lossy audio and original CD. Test was blind. Everyone voted privately to the person organizing it. I listened and found two files to sound the same so voted that way. Results were posted later indicating I was "wrong." And a famous "engineer" who mixed movie soundtracks had gotten it right.

Puzzled, I go and do a binary comparison between the files. I find them to be identical to the last bit! I go to the test organizer and tell him this. He can’t believe it and not accepting it. I explain the results and he goes and checks. And finds out that he had mistakenly uploaded the same file twice! He declared the test invalid.

Meanwhile the "engineer" is furious and insisting that this can’t be. He was so sure of his golden ear abilities. Yet he had voted two identical files differently. Why? Because he was told they were different.

Here it is if you want to check (post #3):

"Thus, I’ve had to re-render the files from the compressed versions back out to 16bit .wav. Doing that, it appears the Tracks 1 and 2 are BOTH the 192Kbps encoded files. Track 3 is correct in that it is the 320Kbps encode, and Track 4 is correctly labeled as the 192Kbps & compressed/boosted track.

[...]

Specific thanks to Amir for speaking up to make sure accuracy prevailed, even though my bad results actually tended to make his company’s codec look even better than it was.

Again with sincere apologies, thanks everybody for your efforts thus far. Sorry to have blown it after the anticipation build up."

I am not posting this to brag about my ability to detect the duplicate. I too could have picked them as different. The main point is that no amount of self-qualification means anything until you are formally tested where we can check answers. Your experience is just an anecdote. If you want it to be a reliable outcome to use as an argument here, you must follow proper procedure to make it so.

Finally, if everyone’s listening tests results are right, my experience with Topping DACs is that they sound superb and transparent. No way, no how would I remotely agree with your assessment. My experience can be backed with measurement and audio science. Yours are easily invalidates using the same.

So I beg you to conduct a blind test and determine for real how those products sound.

Basically, Amir is the world’s greatest cynic.....He believes that we cannot believe what we hear. We can repeat an A/B a thousand times and hear the same difference but Amir believes we have fooled ourself thousands of times. He does not trust his hearing....he must be deaf! He does not trust anyones hearing.....we are all deaf! The one that is deaf is certainly Amir.......for he has his hands over his ears and will not listen.....but just keep sqawking like a parrot. We need to teach that old bird some new words.....sqawk...sqawk...sqawk.......yet no truth comes out.

I'm happy to call out Apos, an authorized seller for those DACs.  Nowhere on their sales pages nor listings do they mention their refurbs are "final sale items." 

Refurbished?  Why are we talking about refurbished products?

Here is their FAQ on returns of new products:

"We recognize the importance of a customer-friendly return policy for audio products. We want to make sure you have plenty of time to test the equipment in a comfortable environment with music that you love before making the commitment.

If you are not satisfied with your purchase, feel free to request RMA (Return Merchandise Authorization) within 45 days of the delivery of the order."

That is darn good return policy, better than Amazon.

Compare that to a power cable I bought from GR Research:

"Company advertising says that you can try the cable out and if you don't like it, you can return it and "get your money back." Close look shows that you are responsible for shipping it back, the cost of shipping it to you and unknown credit card charges. I paid $40 for shipping for 2-day service ($25 for standard ground). So if I ship it back the same way, I will likely incur some $80. For this much money, could have bought a dozen ordinary AC cables. So much for money back guarantee. "

Indeed I got hit with those fees.  Worse yet, company no longer accepts returns on these products:

"

Custom Orders (Finished cables, cabinets, and speakers)

(Applies to all orders placed on or after August 11)

All fully completed cables, finished cabinets, and speakers are all custom built to order.

• Full-refunds are only possible if cancelled within 24- hours.  (standard 3% cancellation fee still applies)
• Partial Refund: Once assembly has begun on your order, only a partial refund is possible up, to the remaining cost of labor and materials at time of cancellation.
• No refunds OR cancellations at, or after, the time of completion/delivery."

What happens if the unit dies after the return window?

A few choices. Post on ASR Forum as reps from all of these companies are active there.  And members may have experiences of the same.  Due to large volume of products shipped from these companies, you will get far more relevant answers than some boutique company that sells 100 DACs a year.

Second choice is to buy a replacement for $200 or even less if you just need unbalanced.

Third option is to send it back to the reseller for repair.  Yes, in some cases this will take a long time as the product would have to go to China.  But again, note that there is essentially no repair of any high-end audio product outside of the country that it is sold.  

Basically Amir is the world's greatest cynic.....He believes that we cannot believe what we hear. 

I don't "believe."  I know.  In my last corporate job, we blind tested large community of our audiophile employees to see if they could tell lossy audio from the source.  They performed miserably, missing flaws that were instantly audible to me and our trained listing panel.  I was hoping we could use our audiophile community to expand our testing this way.  But it did not work out and served as an embarrassment to me.

You simply are not critical listeners.  You perceive a difference where none should be and instead of thinking hard why that could be, go around brag that you heard the difference.  Not once do you allow anyone to grade you.  You take the test.  Give yourself A+ and keep going.

Just because you have ears and like music, doesn't make you able to hear better than average person on the street when it comes to non-obvious differences.  You need to learn this.