What's next for the test bench?? A slight deviation from plan, and I will tell you why. I happened to be perusing Amazon looking at various source components that I find interesting, and I came across the SMSL D300, which uses a Japanese chipset I have not yet heard of.. the ROHM BD34301EKV.
It caught my eye, because it appears to convert DSD via native analog FIR, and ONLY that way. No 'DSD processor' or 'DSD direct' to choose from. The block diagram seems to say it is ONLY DSD Direct. I also like what the data sheet has to say about the DSD FIR filters. It is very straightforward.
It is also a segment DAC. It doesn't say exactly what those segments are, but one of them must be a Delta Sigma segment. Which means the other is some kind of true PCM conversion, most likely. The diagram gives no indication of any but a Delta Sigma modulator for PCM, but since it does say its a segment DAC/filter then I would say its very likely all a thermometer code DAC with PCM'S msb's converted with a number of equally weighted switches that do indeed bypass the DS-modulator. Just a guess, though. If I am correct, then its very much like the Burr-Brown DACs developed in Japan before TI took ownership.
It arrives tomorrow, and testing will begin after after a 48 hour break-in over the weekend.
Can't wait to see how it compares to AKM and ESS based products at this $400 price point!
One of the backbones of my audio lab is the RME ADI-2 PRO FS R Black Edition. Quite a title, eh? I suppose lots of numbers and letters appended to the end is appropriate for a top of the line ADC/DAC.
The RME can't quite dig deep into the noise floor of the latest Chi-fi DACs that are being custom built, by their own admission in their 'mission' statement, to perform on the bleeding edge of the very latest Audio Precision test analyzers.
For my own bleeding edge dive into the world of the noise floor, (kind of like sinking into Challenger Deep), I decided to fight fire with fire. I purchased the E1DA ADC and APU (Audio Processing Unit with pre-analyzer notch to assist in measurements of THD and SINAD) from the Silicon Valley of the East, the Shenzhen 'Special Economic Zone', from whenceforth Topping, SMSL, Gustard, etc all come.
On an aside, Shenzhen (once called the less than sexy "Sham Chun"), looks like something straight out of Star Trek. The 'home base' on Terra in the 24th century would look like this in my dreams.
But now, it isn't Topping under the knife. I finished all those measurements and am planning on having those reviews (E70 and E70V) up by midnight Eastern Time this day. A day late, but better late and somewhat informative than on time and a bunch of crap. Under the knife is the RME ADI-2. (We will just call it that from now on, and we all will know the reference is to RME's state of the art top model)
By any reasonable standard, the RME ADI-2 STILL is an impeccable piece of engineering, with measurements that completely blow past the human ear's resolution. That is why it is also marketed as a home lab measuring device, since the vast majority of hi-fi kit even to this day will not reach the specifications of the RME.
Here is what I found in my non-literal look under the hood. Although we could do that too, someday.
A special ADC/DAC or ADDA. One that will always be here. One of two products I will never sell. This RME, and my iFi iDSD PRO. (my iDSD has a iffy OLED display, so maybe someday I will just buy another one, but it will be a DAC I have until it dies.)
Pictured above is every reviewer's dream piece. A very select few are lucky, lucky to have them. These are typically reserved for large audio corporations who need the best of the best for prototyping the latest product on the drawing board. The most wealthy magazines have one in the office, and maybe even an older spare in someone's home. Maybe someone even invented their own proprietary measurement interface and software and sells it as well as uses it to let their audience in on what is going on underneath the hood of the kit of the day under review.
Surely, Surely such results can't be replicated in the amateur enthusiasts lab? Well, that would be correct. They cannot. There are certain things that just require this level of perfection. Alas, all seems lost. But, wait a moment! NO! It isn't!
For all the things we can't do as well, there are quite a few things that we can do as professional reviewers stuck in amateur labs! Some recent products out of China that take direct advantage of the latest ESS chipset's harmonic distortion cancellation, along with creative minds and somewhat eclectic collections of software can provide results of which any reviewer should be proud!
Now, That day IS coming when I own something like the Audio Precision, although I think I will stick with the new Dscope M1 from Spectral (formerly Prism).
I am hoping within the next year or so to have such a fine state-of-the-art Audio Analyzer in the lab.
In the meantime, I MORE than make do with E1DA products, that are a BOON for budget audio analysis!!
What kind of boon you say???? Well, lets just say MOST average hi-fi equipment, no problem. With the combination of the E1DA COSMOS ADC and APU (Audio Processing Unit), most average equipment is no problem. Which brings me to the problem. The latest two DACs in the lab made by Topping. The E70 and E70V sister DACs, the only difference being one's heart is the ES9028, while the other is the very latest AKM AK4191+AK4499EX split chip DAC. I say 'only difference', but internally, that difference is pretty major.
The big problem for EuphonicReview is how to get accurate measurements on these two DACs. It wasn't easy. Every day was a learning experience, but, finally, right before my publication deadline of February 10, everything clicked into place.
Again, there are lots of measurements that I cannot match-up with an Audio Precision, but, you might be surprised how close in the end some of the most important measurements can come.
I give a big shoutout to Amir at audiosciencereview.com. We are going to stick to the Topping E70 DAC with the ES9028 chipset, because I know he recently reviewed it with his Audio Precision analyzer. Below is a comparison of his results with the AP, and mine with the E1DA Cosmos.
So, less than 500 dollars vs I am guessing 20,000 dollars. Not bad! Did you expect the results from the Cosmos to be so very off the mark? I did. Because the Topping E70 DAC has measurables that push the limits of the Audio Precision. Pushes them hard. And it pushes my lab to the very, very limit. But they are NOT that far off the mark. Impressively in the neighborhood IMO. Anything more, and I don't believe I can provide useful commentary. The highest SINAD DAC I have yet measured happens to be the sister DAC of the E70, the Topping E70V. 'V' as in 'Velvet'. I measured its SINAD with same setup at 121.3db, or 0.000086% THD+N.
At the moment, yes, I am satisfied with the marks I can reach. But I know the day is coming when my marks will fall more and more behind as technology keeps advancing. So eventually an upgrade is in order. But, for NOW, I can say with great confidence I can provide useful measurements in my reviews for anyone considering the product I am evaluating. Most especially when compared INTERNALLY to other products reviewed here at www.euphonicreview.com.