DAC-OFF: Soncoz SGD1 vs. Geshelli JNOG

Fair enough Mr Purrin. I can't see the lettering on the DAC chips in the photos. Can you take a better picture? Is this chip ES9038Q2M? Is this cause of bad measurements?

 

To add to this, I had a demo unit here sent by a friend, whilst I don't have an ap analyser either (i'm actually using an ADI-2 pro ADC as it's to my knowledge the best measuring standalone ADC which also supports ranging input sensitivity), I was unable to get anywhere close to the same measurements as ASR, and saw similar to what is displayed here, with much higher third order harmonics.
Of course I never expected to get as low as ASR as you'd need a notch filter to achieve that (which I don't currently have but if anyone here would be happy to build/sell me a balanced analog 1khz notch filter shoot me a msg), but the fact that I was still getting better measurements with some other dacs I had on hand had me curious.

I don't have these measurements saved unfortunately, in honesty I sort of assumed I must have just done something wrong and so didn't save or post them anywhere. But i'll see if I can get that unit back from the friend who loaned it to me at somepoint and re-check it.

I do however have the LA-QXD1 which I purchased myself to review so i'll see what I can get from that

 

Also a suggestion (stolen shamelessly from TalbotHound ): perhaps the 'IMD Hump' fix they applied has resulted in poorer THD performance.
I believe Gustard mentioned somewhere that this was the reason they'd not implemented an IMD hump fix in some of their products? Because they could get better THD by not fixing it

 

This might be something to do with the revision that removed the IMD hump. All the previous measurements had been done with a version that had the IMD hump.

 

The two DAC chips are the rectangular chips right above the LPF circuit. There's a third rectangular ESS chip which is a regulator made specifically for these. And AFAIK, the 9038Q2M aren't faked. Good manufacturers however, set thresholds for underperforming chips. 124dB dynamic range is typical, can vary up to or below <=120dB in the crappiest ones. These are mobile grade after all, not PRO. The 9038PRO in turn suffer from thermal problems varying chip to chip.... ESS is a crapshoot lol.

 

Yeah i have photos from inside mine of all the chips and it is definitely a 9038Q2M.

 

I can't imagine they'd have faked the actual chips themselves. Especially given the other aspects of the design that likely have added significant cost to the BOM like the dual transformers etc.
It's most likely either QC variation/failure to check.

Or something that has changed recently, the only thing I can think of being the IMD hump as talbothound mentioned.
The capacitor values on the output stage did change

 

From L7audiolab

https://www.l7audiolab.com/wp-content/uploads/2020/07/Fixed-SMPTE-Ratio.jpg

 

Is it safe to assume that all these filters are built in to this ESS ES038Q2M chip - even if they have been (re)named by Soncoz?

 

I would not bother as the chances they programed there own are pretty low IMO. Its just more cookie cutter stuff...

 

There is either something funky happening with that particular unit or Soncoz screwed something up as those filters are not supposed to have that kind of response. ESS filters are generally sharper than their AKM equivalents. Jnog uses the short delay sharp linear phase I believe, the ess fast linear phase should show earlier and slightly greater ultrasonic suppression.

Might partially explain why it doesn't sound particularly good if it is a botched implementation . That being said beyond figuring out rather this unit is defective which would require a 2nd unit to confirm there is not a huge value in doing a load of measurements again.

I would not be surprised if the implementation is off as ESS documentation is notoriously bad and it takes a lot of effort to get those chips sound right.

 

Hi,

Just wanted to share my experience with the the new JNOG… Listening impressions is all I can share, as I have no technical notions.

I have owned three DACs in my life :

• a french Atoll DAC100 (entry level with Burr Brown) : I couldn’t listen to this without lowering the volume after a few seconds… Sound was like ’sticking’ to the air, giving an unpleasant ‘saturated’ effect, as if the DAC didn’t know how to move from a sound to another :-(
• my actual Metrum Acoustic Musette : quite the opposite ! Natural flow, much more details, natural staging (not « in the face »). With a good power cable, that Musette remain with me for five years, giving constant satisfaction

Wy did I order the JNOG ? Mainly by curiosity, as I see so many discussions about R2R vs Sigma-Delta DACs. How a good D/S DAC sounds ? That what I wanted to know… It’s probably unfair to compare both DACs, as one is more than 3x the price of the other, but I can’t resist the temptation

That second version of the J2 (let’s call it J2 v2 ?) il running since 50 hours, linked to my old iMac.

Right out from the box, my first impression was : the VOICES ! How good they are, how immaculate, how lisible ! Across favorite songs I could suddenly understand many words that didn’t reach my mind before… WHAOOO ! But very soon after that, I was struck by how thin the treble was… Flutes, cymbals, violins, trumpets sounded so slim… no texture at all ! And goodness, where the lows had gone ? Was it possible that only the ‘mids’ sounded so good ?!

I plugged an Intona Hi-speed Isolator between Mac and J2 v2 and let it run a few hours before coming back. Everything appeared more balanced yet, but still that thinness in the highs, and something a bit blurred in the lows. Next to the Musette, J2 seems to ‘fight’ with the lows. But anyway, it’a easy to hear how refined the J2 v2 sounds : it’s all about separation, delineation, making every musical line sound so clear, so intelligible… Musette is a raw force next to it. But maybe Musette’s ‘full-bodied’ sound makes the listening experience more… natural ? More direct ? More communicative ?

As I write these lines, J2 runs since 50 hours and I must say I enjoy it more and more… Is it possible some components inside need to warm up ? Texture seems to come, lows are much better… Or maybe my ears just get used to it ?

Note that J2 is fed with its provided little supply… Would a 12v LPS enhance the experience ?

Hope these impressions can help ;-)