LAiV Harmony R2R DAC Impression and Reviews
May 25, 2024 at 3:08 PM Post #226 of 402
Not entirely correct (there is such a thing as Voltage Volume control – straight off Dac Chips to output) but I agree in that (for me at least) … a Passive Pre (not DSP) or at least a completely transparent one, will interfere much less or not at all, with Source signal info (as per Mr. 6 Moons). So the Preamp will be important imo (for my taste), as next link in the chain. That’s the advantage of a straight Dac – you can tailor sound to suit yourself downstream if purity of Source is secondary.
What dac chip do you mean? There is no dac chip in an R2R dac that already puts out line level voltage. With a SD dac chip there is only very low voltage and you need an elaborate well made I/V stage (or opamps, or tubes or discrete transistors). Then you can implement a volume control. But after an R2R array of resistors, thing are extremely minimalistic. On my old R2R DACs (tda1543) I only used 1 resistor (output resistance) and that was all (and get rid of any DC offset). And that's why it sounds so good.
From there you go to a preamp or integrated amp with the best volume control and input selectors (relais) straight to amplification.
 
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May 25, 2024 at 6:21 PM Post #227 of 402
Well the truth is dac differences are really small and do not alter the sound(nor meant to) in a big way. The speakers matters more then any other equipment in the chain. But if your chain is already up, then maybe a upgrade to the DAC is worth it for the pursuit of the last mile.
This is always a difficult subject. And there is a diffentiation that is often underestimated. I'll try to explain short and sweet.

Transducers that convert electrical to dynamic energy or vice versa (microphones, pickups and speaker drivers) have a hard time keeping the amplitude linear over the frequency range, within the audible range. Those are what you call 'big differences'. But in fact, your brain can compensate for that. You get used to a 'sound'.
Then there is, damping factor and rise time. That is interaction between amp and transducer but is mostly an electric issue. But it touches on the next issue.

DACs and amplifiers produce a ruler flat frequency response. So those are considered 'small differences'. That is if you only look at one dimension. The other dimension I consider just as, or even more important. And time is the time domain. This is something your brain can not compensate for or get used to. That is used for localisation, spatial dimensions, hall, reverberation, echo, width, height and depth. That is how we perceive our surroundings. That increases or decreases the sense of realism. The illusion of being there. You can create that with a really good source, a simple amplifier and a 4" paper fullrange speaker. Not with a million dollar system and a $500 dac.

I know because I built that. It lacked low bass and a $10 amp lacks refinement but the sense of being there was uncanny. A subwoofer already made it pretty complete. Too bad the person I made it for doesn't have the finances to get a really good source but the foundation is there.

Often you hear 'source first'. I largely agree. I tend to look at it as 'start with the maximum of information and try to retain as much as possible with every step'. And 'weakest link in the chain' means you have to find a balance too. And 'synergy' is the third thing, build strenght upon strength and not waste it on big efforts to compensate for some shortcoming.
 
May 25, 2024 at 6:52 PM Post #228 of 402
DACs and amplifiers produce a ruler flat frequency response. So those are considered 'small differences'. That is if you only look at one dimension. The other dimension I consider just as, or even more important. And time is the time domain. This is something your brain can not compensate for or get used to. That is used for localisation, spatial dimensions, hall, reverberation, echo, width, height and depth. That is how we perceive our surroundings. That increases or decreases the sense of realism. The illusion of being there. You can create that with a really good source, a simple amplifier and a 4" paper fullrange speaker. Not with a million dollar system and a $500 dac.
+1 / 100% agree re critical importance of time domain accuracy. This from experimentation with external clocks on several DACs and DDCs, including improving their power supplies, grounding and vibration damping, incl DIY direct vibration damping of oscillators both external and internal. It’s not only those important time related spatial and decay aspects you mention, but also timbre and textures of instruments, texture and micro-detail of vocals, super subtle detail our hearing is very attuned to that gets smoothed over with even a small amount of time domain inaccuracy. Not to mention improvements to transient impact, bass weight, incl the realism thereof.. less etched, more nuanced and believable.
 
May 25, 2024 at 7:16 PM Post #229 of 402
Published my review on both head-Fi and YouTube.
"Secondly, I cannot reliably pick out the differences between OS and NOS nor the Positive/Negative Phase".

That is interesting – I think you are the first to mention on that subject. Other Dacs that do both – at least from reviews I’ve read, always make a distinction. Maybe the designers have purposely tuned them to sound similar ? As for Phase, this is normally discernible but a little subtle. Never tried on Phones but main Speakers do/should reveal it.

When GoldenSound’s review pops up, the NOS subject may get a mention. As he’s revealed, not all NOS Dacs (at least Mnfr claims), are in fact true NOS designs. As with Balanced gear – not all are truly Balanced. Off subject but he’s a bit of fresh air to the Audio sector – only 21 and v clued up tech-wise. And recently claims he can hear just above 20kHz. That is some claim.
 
May 25, 2024 at 7:28 PM Post #230 of 402
May 25, 2024 at 8:55 PM Post #231 of 402
For some techy stuff check 6 Moons (sorry) or the Mnfr. There are devices operating with Lossless variable voltage volume control. There’s at least one other Mnfr doing something similar I’m aware of – but not the first.

For a simple explanation of one and easier read :

https://twitteringmachines.com/review-sonnet-digital-audio-morpheus-dac-and-hermes-streamer/
Very interesting. In my understanding there is no dac chip inside the Laiv. How else do we explain the stated resistor tolerances. And the specs don't point to this either. I was assuming there is no chip inside. But what made me suspicious is the small size of the gold wrapped R2R modules compared to the huge size of the rows of resistors in for example the Holo and Denafrips DACs.

So what is under that hood?

But now I understand what you meant by variable voltage. You vary the voltage that goes IN to the ladder. Instead of a fixed voltage. As a non EE I'm not fully aware of eventual implications for the behaviour of the resistors with varying tension when they get really low (threshold?).

If I translate that to my old tda1543 DACs the 3V offset would also vary with that. Only in that chip it won't work as it's always 3V no matter Vin.
 
May 26, 2024 at 4:59 AM Post #232 of 402
Connectivity is all personal & dependent on gear (not to mention Cable) choice. You might find the Audio Engineering Society (AES) and Euro Broadcasting Union (EBU) disagree on that front. There’s one opinion from a Digital designer though, that of more importance, is the care taken over the input/output devices themselves – rather than Cables.

RCA (& USB/HDMI) were never designed for Digital. BNC, AES & I2S were. It’s good to have choice to find out but most agree differences can be small. Personally I have always favoured all 3 of the above over USB/RCA/Optical. My (old) Digital CD Transport for example, does not offer RCA – only AES/BNC and 2 Opticals – Glass (now redundant) and what they politely called … Plastic.
AES proclivity is entirely depending on "not trusting" a particular USB input and offloading the duty to a clock or DDC in this space.

In pro use it is much more a hardware before anything else.

I2S is a digital format without a standard which again, lends itself to a belief or trust in a DDC and offboard clock over USB straight implementations.

To make declatory statements about a pro format synchronous connection has to be placed in context. That context may be reduced to "because I like it" but that is not substance to support "the best digital connection".

In a world where people are claiming to distinguish and prefer jitter differences below clinically studied human perception limits, it's a sweeping claim to make when it's dependent upon a clock.(which is a sleight upon the MFR/OEM Engineering and places heavy subjective interference upon the engineering behind the chosen components in the system)
 
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May 26, 2024 at 5:01 AM Post #233 of 402
Time domain is definitely a thing but how much can one pick up is probably as subjective as anything else.

In hearing stuff, I don’t think my hearing is absolute and I know my ability to remember sound is worst. That’s why I don’t do reviews without an actually comparison switching at the verse level. Short of a blind AB, this is probably the next best thing considering how flaky memory is. And for NOS and OS I can easily do blind since I can use the remote control click real fast and have no idea what is the exact state since some clicks are dropped. I never managed to reliably guess after many tries.
 
May 26, 2024 at 5:09 AM Post #234 of 402
Time domain is definitely a thing but how much can one pick up is probably as subjective as anything else.

In hearing stuff, I don’t think my hearing is absolute and I know my ability to remember sound is worst. That’s why I don’t do reviews without an actually comparison switching at the verse level. Short of a blind AB, this is probably the next best thing considering how flaky memory is. And for NOS and OS I can easily do blind since I can use the remote control click real fast and have no idea what is the exact state since some clicks are dropped. I never managed to reliably guess after many tries.
I'm referring to time domain preferences which are measured well below human perception.


There's Golden Sound who claims 22khz threshold without medical professionals backing up. Maybe he can, maybe he can not. I remain skeptical.

There's many people online who claim they prefer pico seconds difference in clocking and will jump over hurdles to explain phase shift on a scale you could not comprehend 20 years ago.

This is religious belief territory not science. People will spend their money how they want.

As for NOS and OS, that's easy. Some 44.1/48khz files in NOS implementation will roll off very early and be tonally apparent. That's why HOLO NOS is almost dependent upon HQP upsampling or those customers who simply don't care and enjoy the music.
 
May 26, 2024 at 1:05 PM Post #236 of 402
There's Golden Sound who claims 22khz threshold without medical professionals backing up. Maybe he can, maybe he can not. I remain skeptical.
Why do we care if a twenty-something can hear above 20 kHz? Do we need proof of everything to accept anything?
 
May 26, 2024 at 1:47 PM Post #237 of 402
I'm referring to time domain preferences which are measured well below human perception.


There's Golden Sound who claims 22khz threshold without medical professionals backing up. Maybe he can, maybe he can not. I remain skeptical.

There's many people online who claim they prefer pico seconds difference in clocking and will jump over hurdles to explain phase shift on a scale you could not comprehend 20 years ago.

This is religious belief territory not science. People will spend their money how they want.

As for NOS and OS, that's easy. Some 44.1/48khz files in NOS implementation will roll off very early and be tonally apparent. That's why HOLO NOS is almost dependent upon HQP upsampling or those customers who simply don't care and enjoy the music.
I disagree on a few things. Or let me redefine the framework. And get some definitions straight. Broaden the horizon so to say.

I learned a lot in school, but what I learned best is that most teachers have no idea what they are teaching you. Besides the language and math you get indoctrinated with a LOT of ideology. One of the Fairy Tales is that by learning you will be introduced into the elite club of Reasonable Men, devoid of alterior motives or emotion. They say "Trust the SCIENCE". And with that you are an acolyte in the new religion of Scientism. Which has its own dogmas, gods and priests. Modern science as it is discribed has very little to do with the pursuit of knowledge but a lot more with establishing consensus. Denying their own foundation in 1 particular religion or worldview. That the universe can be studied and abides to common laws. Laws that apply always and everywhere the same. Without that faith there is no workable scientific method. So much for "science as opposing to "religion". They MUST go hand in hand.

The thing I would like to pull apart here is timing. I was talking about sound. Not timing of digital signals. Analog sound as perceived with or sense of hearing and the brain as processor of that digital input rendered by the synapses. Yes, our eyes and ears are biological digital sensors. Lots and lots of computing going on in that grey matter between our ears.
But here is my point: over 90% is not conscious. Like in a computer most things are machine instructions (lower level language) that are not visible for the user on a UI (user interface). Yet errors can very much throw a spanner in the works. Most of our hearing is subconscious. Just put one finger in your ear and notice how your 3D perception is totally distroyed. That is the same as having a hearing aid: you can't follow a conversation in a crowd because you can't locate anymore on timing differences between 2 ears. And thus you can't focus on one location you are listening to.

Back to my 2 dimensions of sound: amplitude and timing. And information and noise. Noise in amplitude is simply called noise. And you know instantly what I mean, signal to noise. That reduces the amount of information. When a sound is twice as loud as a similar sound or overtone, that's 10dB difference, the lower sound is masked. Yet when there is noise from everywhere you can still perceive 1 signal if it's 40dB (iirc that is) below the noise floor. Like a voice in the crowd. That is pretty amazing, 10⁴ difference in volume.

That is also due to timing. But what if that voice in the crowd is like 4 voices saying the same thing? Or 10? That's not so easy anymore. Heck, it's hard to understand a choir singing the same song even when the background is quiet. And how irritating is it when one eager beaver is starting to sing just ahead of the rest because he has a bad sense of timing?
Back to those 4 voices in the crowd. You can't focus on 1 pinpoint anymore. It's turned into an area, a wider spot with differences in timing and amplitude. That is noise in the timedomain.

But what to call noise in the timedomain? Distortion? Smearing? Confusing? Quantum physics? It is confusing. And most often it's not even consciously. It seems that people can believe 2 conflicting statements as true at the same time. That's called cognitive dissonance and you can often tell because they fall flat, their brain goes on tilt when asked about one or the other. It also causes headaches and irrational behaviour. That's all unconscious. The brain can't produce 1 clear conscious answer. Try and scientifically study that! You'll get a different answer every time. Like Schrödingers cat.

Besides the tangents, timing of sound is much more important than we think, because it's in our subconscious non-think area. It's the iceberg we can't see.

Finally, on NOS and oversampling.
NOS doesn't cause HF roll-off, it's the filtering that does. It's the pre- and post ringing that makes the HF sound clearer (in other words its artificial detail). Oversampling causes pre-ringing. That like the arithmic singer in the choir. A pond never starts to ripple before the stone hits the surface. That causes our brain to come up with an explanation from the natural world that makes the impossible possible. Result: brain freeze, cognitive dissonance, headache, listening fatigue... Post-ringing is much less of a problem as is is much like physical resonance, reverberation and harmonics.

And now my sense of timing tells me I've ranted for far too long. 😄
 
May 26, 2024 at 2:03 PM Post #238 of 402
Why do we care if a twenty-something can hear above 20 kHz? Do we need proof of everything to accept anything?
Nope. That's why I didn't go in to it. It's just a statistical rounded off average. I could hear it too at that age. Not anymore. Instead I am rewarded a constant high pitched tone in both my ears. That's called tinnitus...

The 20-20kHz is just an easy to remember number we learn in school. So that's it, done. Next. Without ever having to doubt it, it's chiseled in stone like from the personal hand of God. Yet it doesn't apply to any one person. That's like saying: man is 1m64 tall. Or; you can't taste anything other than spicy when you are eating spicy Asian food.

The 20Hz is even more arbitrary and foolish. Because the ear isn't our only sense that can register sound. We can sense way below 20Hz. And I'm not even touching above 22kHz, because I'm not a flat-earther.

We are often only given the mnemonic without the parameters or boundaries. Without the frame where it applies. In dutch we call that 'ezelsbruggetje', donkey bridge. Where the supposedly dumb donkey can easily pass the stream. Something that is easy to remember so you can get on. Like a thumbnail of the big picture. Too bad people often know nothing about the big picture.
People tend to get polarized when the big picture doesn't fit their thumbnail.

Information is fascinating once you realize where it comes from...
 
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May 26, 2024 at 2:14 PM Post #239 of 402
I really do not expect an upscale dedicated discrete R2R DAC to be equipped with a digital volume control. You know why? Because an R2R dac has a minimal output stage that keeps the signal as pure as possible. A digital volume has to be done before the R2R ladder. Therefore discarding bitdepth. So you are going from 24 bit to 14 bit, 12 bit or 8 bit, depending on your volume position. That is a very bad and stupid way to attenuate a high power poweramp without volume.
When I bought my DAC from Sonnet they told me something about the volume control they have implemented where there is a jumper inside to reduce reference voltage by 3 to get -10db attenuation. I can’t find that old email but there is something similar in 6moons.
https://6moons.com/audioreview_articles/sonnet-pasithea/6/
IMG_2152.jpeg
 

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