Wolfx700 Measurement&Review of Luxury&Precision P6

[Skeptischism]

But thats what you did... you compared to desktop R2R dacs and now you complain when I bring out the reality of such a comparison? the MSB is ridiculously bad; yet another with horrible spurious tones making ingress into the dac analogue output from the power supply. They may actually be the worst performing hiend dacs i've ever seen. Even stereophile had a difficult time defending the performance.

I find the whole idea of building discrete R2R puzzling ... and having made a decision to design another one, why bother doing it if you are only going to use such small SMD resistors? given these are your main source of noise and distortion and 0805 and 1206 size are significantly better than 0603 or 0402 in this regard.. the problems you face doing it discrete are related to the matching of the discrete resistor elements and their TEMPCO. have a guess what the best past, present and future way of combating this is? laser trimming on chip resistors in an IC.

One could posit that taking the difficult proposition of making a discrete R2R portable and getting about the performance one might expect from that decision (terrible) wasnt the best use of resources ...

It looks like and measures as one would expect such a design would. Audio Dacs were designed decades ago, to decode the digital output from a CD. for this amount of engineering to fall short of being able to resolve CD quality 40 years later at a cost of 3000USD, isnt what I would call a great achievement. that it is similar to other failed attempts at this design problem is unsurprising.

 

[Skeptischism]

That being said, I quite like the chassis design and volume knob. the PCB designer also appears competent. Perhaps the problem was more in the brief?

Perhaps all these companies making very similar discrete R2R dacs would do better to get together and throw some money at getting a small run of bespoke R2R ICs made? Ether that, or like others have done, design a digital filter and interface for high performance industrial R2R chips like the DAC11001A from Ti actually i'm yet to see one using this new chip. its performance appears very good.

 

[YSC]

But thats what you did... you compared to desktop R2R dacs and now you complain when I bring out the reality of such a comparison? the MSB is ridiculously bad; yet another with horrible spurious tones making ingress into the dac analogue output from the power supply. They may actually be the worst performing hiend dacs i've ever seen. Even stereophile had a difficult time defending the performance.

I find the whole idea of building discrete R2R puzzling ... and having made a decision to design another one, why bother doing it if you are only going to use such small SMD resistors? given these are your main source of noise and distortion and 0805 and 1206 size are significantly better than 0603 or 0402 in this regard.. the problems you face doing it discrete are related to the matching of the discrete resistor elements and their TEMPCO. have a guess what the best past, present and future way of combating this is? laser trimming on chip resistors in an IC.

One could posit that taking the difficult proposition of making a discrete R2R portable and getting about the performance one might expect from that decision (terrible) wasnt the best use of resources ...

It looks like and measures as one would expect such a design would. Audio Dacs were designed decades ago, to decode the digital output from a CD. for this amount of engineering to fall short of being able to resolve CD quality 40 years later at a cost of 3000USD, isnt what I would call a great achievement. that it is similar to other failed attempts at this design problem is unsurprising.

Well, my mention earlier on desktop is that as to explain how I admire it able to outperform big names as MSB or so, considering how many of R2R dacs out there and only a few like the holos did outperform this DAP I don't think my original statement of that almost none of the multigrand R2R did better, which I don't think I need to withdraw that statement.

And I don't think my saying of not fair to compare desktop to DAP is for a respond to the price no object comparison saying that this should outperform the Holo is wrong either... it's two different things:

1) This outperform a majority of DAPs, and with R2R especially discrete, few (almost none in my language) in desktop multi grand ball park did better, so extra points given.

2) Yes there are cheaper desktop DACs did better, at a lower price, but this is to be expected if their tech level is similar as desktop is far superior in design limitations, thus I still admire the designer

And for the last paragraph, I kind of agree and disagree, yes you can get better objective quality at a fraction of cost, which I believe most ppl here do, I personally DON'T own this thing and won't pay $3000 for this, but for those who wanted R2R for whatever reason, this is reasonably good in a DAP category, just like I won't buy a vintage fuel drinking 70s porsche which is easy to spin, but well, for those who love a 1970s sports car, it's still a great performing sports car

 

[YSC]

That being said, I quite like the chassis design and volume knob. the PCB designer also appears competent. Perhaps the problem was more in the brief?

Perhaps all these companies making very similar discrete R2R dacs would do better to get together and throw some money at getting a small run of bespoke R2R ICs made? Ether that, or like others have done, design a digital filter and interface for high performance industrial R2R chips like the DAC11001A from Ti actually i'm yet to see one using this new chip. its performance appears very good.

This being said, I think I read somewhere that current R2R dacs are more for industrial use and not really suitable for audio use with lots of constrain (If I recall correctly, it's something in discussion of the Schiit Yaggy), as for some R2R interview I don't remember is that from Holoaudio's designer in Chinese or so, it seems that old legend R2R ICs like PCM1702 arn't performing great in modern standard, and the market isn't large enough to push IC makers to invest in design and manufacturing such ICs.

Being Discrete allows designer a lot of freedom to use their FPGA or other means to do correction and implement their own filtering etc. And from a geek standpoint, I purchased the Spring 2 more on it's artistic look and way that it can do it right with discrete NOS R2R performance, was it better objectively than a cheap Topping D30? NO, was it better subjectively? hum~ no, the rolled off highs in NOS mode is which I kinda like though, and my money is going for supporting what Holo is able to do.

And back to DAP, currently I am using a Sony ZX300 which measurements here by @WolfX700 shows even worse results in 8x dB SINAD, which I still thinks good enough for on the fly usage with my UERR, I am disappointed seeing it's performance but than it tells me that the past research of CD quality is correct, CD quality already covered what is possible for best case audibility of flaws in sound reproduction, and that 8xdB SINAD in my ZX300 is already not discernable if I change back to my 108dB holo spring 2 desktop setup with same Tidal music list.

So somehow after lurking here for quite a while and purchased my Genelec desktop setup and the Holo Spring 2, my personal conclusion is: read the reviews and enjoy how far tech had gone by, but although technically CD quality is still a benchmark to a lot of gears, something >80/90db SINAD is actually not audible in real music (or unless you replay again and again trying to spot them) and more for the peace of mind. And for my own value, I won't even considering ppl who chase after tubes silly, if that's what they like (rolled off highs etc due to distortion), let it be, just I personally don't go after that

 

[Skeptischism]

Erm, yes, thats why they are called 'industrial R2R dacs' and that is exactly why you need to design a digital filter and input interface (which you would probably just do in an FPGA) they dont accept i2s input, generally SPI or similar is used for industrial DACs. You need to roll your own interface IC if you want to use them for audio, but compared to doing exactly the same thing for a discrete R2R, it is not any more difficult.

as far as getting an IC made ... ESS dont make their own chips, they use a foundry. if they were really chasing performance, rather than sales, thats what they would do, but discrete is a very good catchword and sells units in hi-end, in spite of not providing any real benefit.


I find all of these DAPs measurements unacceptable, so I would always use a player, with a dac/amp rather than a DAP.

with all the facts considered, 80-90db is NOT acceptable for use with sensitive IEMs, particularly if you are using digital attenuation. you might only end up with 70dB. I use JH13 BTW and have been doing just that (portable dac/amp) for nearly a decade.

I'm designing a few dacs at the moment. if I had the software skills and resources I might have a bash at a DAP. there is no real reason they have to be THIS bad. I feel they are trying to put too many features in and this causes noise and their mixed signal design skills are lacking. when you take a dac chip capable of -120dB and only get -90dB, a serious design review should be undertaken.

 

[YSC]

Erm, yes, thats why they are called 'industrial R2R dacs' and that is exactly why you need to design a digital filter and input interface (which you would probably just do in an FPGA) they dont accept i2s input, generally SPI or similar is used for industrial DACs. You need to roll your own interface IC if you want to use them for audio, but compared to doing exactly the same thing for a discrete R2R, it is not any more difficult.

as far as getting an IC made ... ESS dont make their own chips, they use a foundry. if they were really chasing performance, rather than sales, thats what they would do, but discrete is a very good catchword and sells units in hi-end, in spite of not providing any real benefit.


I find all of these DAPs measurements unacceptable, so I would always use a player, with a dac/amp rather than a DAP.

with all the facts considered, 80-90db is NOT acceptable for use with sensitive IEMs, particularly if you are using digital attenuation. you might only end up with 70dB. I use JH13 BTW and have been doing just that (portable dac/amp) for nearly a decade.

I'm designing a few dacs at the moment. if I had the software skills and resources I might have a bash at a DAP. there is no real reason they have to be THIS bad. I feel they are trying to put too many features in and this causes noise and their mixed signal design skills are lacking. when you take a dac chip capable of -120dB and only get -90dB, a serious design review should be undertaken.

Emm~ yes on the dac/amp module usually performs better, somehow I was using that something like 7-8 years ago, but then things changed before I bought the ZX300 in believe of Sony (which was wrong), mostly because of a few reasons I decided to go for the lower SINAD one with sensitive IEMS:

1) The USB connection degrades fast with strain, saying pulling the package from my trousers pockets with the phone, in a short time the sound and connection cuts off now and then when the iphone or the dac side port degrades, which makes the phone itself plays full volume, which is embarrassing in a quiet place like library, office, or a commuter bus...

2) Dac/amp drains my phone battery fast, both a bad thing if I can't get a recharge anytime soon or I need to use the phone in the day on site, plus changing batteries when it is used extensively daily isn't cheap either

3) lot less data usage when I can use the DAP wifi to stream and a SD card full of musics I use when streaming is not needed.

That's how I ended up ditching the higher performance and cheaper dac/amp bundle with my phone and go with the DAP route eventually, so if a great SINAD DAP is out I will adore it if cost is reasonable, or else I would prefer a DAP with sacrifice on SINAD, and usually I appreciate DAPs with analog pot used not digital attenuation

 

[Skeptischism]

when presented with such a problem as your USB cable issue, I usually turn to DIY (right angle connectors on both ends make a very short and durable USB cable)

dac amps drain your battery fast? I presume you are powering them with your phone and the units you use dont have their own power supply?

the sort of analogue pots you can fit in a DAP are not going to provide any benefit. digital is far and away better, as long as you have the DAC performance and your gain staging isnt broken.

data usage is meaningless to me. you can get unlimited phone and essentially unlimited data (as far as phone use is concerned, 100Gb) for $25AUD a month here.

when your daps dont actually perform better than a $9 apple dongle, there is at least for me, no reason to use them.

 

[YSC]

when presented with such a problem as your USB cable issue, I usually turn to DIY (right angle connectors on both ends make a very short and durable USB cable)

dac amps drain your battery fast? I presume you are powering them with your phone and the units you use dont have their own power supply?

the sort of analogue pots you can fit in a DAP are not going to provide any benefit. digital is far and away better, as long as you have the DAC performance and your gain staging isnt broken.

data usage is meaningless to me. you can get unlimited phone and essentially unlimited data (as far as phone use is concerned, 100Gb) for $25AUD a month here.

when your daps dont actually perform better than a $9 apple dongle, there is at least for me, no reason to use them.

I actually used an angled usb with my oppo ha2 back in the days, and the cable itself dies or gets loose easily after a few months of use which I need to pull out the whole package quite often (personal use case). And the annoyance to others in those rare cases I did experienced in office making it a ban to use cable connected dac amp usage in office or crowded bus were a lot of ppl sleeping.
For battery drainage I mean when a phone need to constantly stream data or WiFi it eats up battery.

back in the days when phone still have a 3.5mm out I was even satisfied using that. But since apple ditched that completely, and it’s internal memory is pricing ridiculous with no sd card slot, it becomes more justified for me to get a dap which have a sd slot, and have WiFi streaming capability.

for the dongle thing I did tried those for my wife, and ended up her iPhone lightening port died of strain in 3 months, and apple cost me a few hundred which makes getting a dap for use makes even more sense, when the dongle on the fly likely kills my phone port which it kills charging capability also, as the phone is a working need and that external cable connection to a dac had those unpleasant experiences, a dap at or below $500 justified FOR ME. Of coz if your use case allow all those potential hazards you are free and better off choosing the dongle or dac amp route, but here in Asia daps sells like hot cake not for no reason

 

[Skeptischism]

I like DAPs and would never argue against their use, but I would never buy one that performs worse than a phone. I guess I just dont understand how/why all these expensive players are so crappy. with them being so bad, I would be tempted to just buy an LG or other ESS based phone and use it as a dedicated DAP. the fact that phones are able to perform better than DAPs, speaks to me of badly implemented RF and power supply design work in DAPs, since it proves there is no hard limitation in the design challenge, as a phone these days is just a DAP with a cellular radio as well as everything else.

hopefully lightning goes the way of the dodo. terrible connector. I dont have enough experience with USB-C to say whether or not its better in this regard yet, but it does on the surface appear better, so hopefully they move to that across the range.

 

[YSC]

I like DAPs and would never argue against their use, but I would never buy one that performs worse than a phone. I guess I just dont understand how/why all these expensive players are so crappy. with them being so bad, I would be tempted to just buy an LG or other ESS based phone and use it as a dedicated DAP. the fact that phones are able to perform better than DAPs, speaks to me of badly implemented RF and power supply design work in DAPs, since it proves there is no hard limitation in the design challenge, as a phone these days is just a DAP with a cellular radio as well as everything else.

hopefully lightning goes the way of the dodo. terrible connector. I dont have enough experience with USB-C to say whether or not its better in this regard yet, but it does on the surface appear better, so hopefully they move to that across the range.

Won't argue on the case where phone out perform DAPs, but seems like the market tells the other way round.. see how LG went out of business and Onkyo Phones go basically no where. personally I would think that it's because the DAPs need to provide more power for less sensitive headphones and good music phones don't, so they put more on power or so side and less on SINAD as that's less noticeable than say, unable to drive some popular phones. and for general, a phone with a proper headphone jack is basically going extinct, that makes DAPs more or less the only way left, hopefully one could sort out the problem, I wonders how the lower end A&K fares though as those looks and features wise are nice