DAC?

[ck]

habo66

imaš zs
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LP

[submat50]

Jaz sem se odloèal na podlagi tega opisa. Sem pa Qutest in moj Bifrost slišal na AB testu vendar ne na mojem sistemu. Prispevek zelo lepo opiše razlike. Na testu sem takoj slišal razliko in sem se odloèil zaradi razliènosti in ne kateri je boljši.

Both are quite different sounding DACs. Qutest is leaner, not a lot of meat on the bones, a touch sterile sounding and can’t hit hard in the bass. Bifrost2 on the other hand is denser and warmer in the mids, has a more burly presentation that is very dynamic and punchy, but the presentation will come across as having a bit of murkiness next to the Qutest. Bifrost2 has amazing macro and micro dynamic character with plenty of texture in the mids. Qutest is more of a high resolution DAC with great separation and imaging. Both are incisive in the lower treble, but the Bifrost 2 is smoother in the upper treble, whereas, the Qutest is going to be overall touch brighter in the entire treble region. I hear the Qutest can be made smoother with a good power supply and source. For me, Bifrost2 has a more analog-like timbre in the midrange over the Qutest. As for the soundstage, Qutest is going to be airier with blacker background and a more effortless separation. But the depth is going to be quite similar on both.

Overall, I find the Bifrost2 more engaging and to my liking than the Qutest. My only issue with the Bifrost2 is it’s lower treble incisiveness, which is a touch more evident on headphones than on speakers. On speakers, not only is this lower treble incisiveness less evident, but also the midrange comes across even more life like than on headphones.
 
Bifrost sem mislil prodat, pa ga še ne bom.

Lp MatjaĹľ

[benma]

Kakšna je razlika (razen v letih) med Bitfrost in Bitfrost2, o katerem je govora v gornjem opisu.
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"Whenever we find connoisseurship operating within science or technology we may assume it persists only because it has not been possible to replace it by a measurable grading." Michael Polanyi

[submat50]

Jaz imam Bifrost I multibit. V zgornjem prispevku pa je govor govor o Bifrost II.


https://www.head-fi.org/threads/schiit-bifrost-2-vs-chord-qutest.957606/

Kot pišeje je II nov DAC ni neka nadgradnja. Se pa tadva DAC- èisto na razlièni naèin tržita.

Moje mnenje:

Schiit se trži samo internetno in mislim da ima veliko "influecarjev" ali kao se temu reèe.

Cord pa ima moèan marketing prodajalci, revije itd.


Lp

[luka79]

[benma]

Ko smo že pri DACih. DAC je neke vrste raèunalnik, ki dokaj hitro zastari. Zato je pred nakupom potreben temeljit razmislek.

Kakšen mora biti po vašem mnenju v digitalno prihodnost usmerjen DAC? Ali naj bo del kombinirane naprave ali samostojna naprava, MQA da/ne (streaming, Tidal, ...), najnovejši formati zapisa, zaželeni vhodi/izhodi, ...
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"Whenever we find connoisseurship operating within science or technology we may assume it persists only because it has not been possible to replace it by a measurable grading." Michael Polanyi

[submat50]

Moje videnje. Nisem se ravno zelo poglobil v DAC-e tako, da me bo lahko kdo poravil. Prvi DAC-i so imeli zelo dobro zasnovo in bi bilo s razvojem pristopa zvokovno rezultat zelo dober. Razvoj in izdelava pa sta bila drage. Razvoj je šel v smer moènih chip-ov ala Sabre itd. katerih izdelava ni bila tako draga rezultat pa slabši. "Tržilo" se ni zvok temveè chip itd. Vmes so se pojavili padalci kot Schiit multibit, Chord, še en zanimiv R2R dac z vrsto zelo preciznimi upori. Nek Danec sem pozabil ime. Seveda pa so tuše pregrešno dragi DAC, ki jih pa ne poznam. Kdor je med študijem spoznal Shannon teorem je mislil, da je pa to to. Sedaj pa vsak DAC poje po svoje.

Moj razvoj sistema. Jaz sem imel približno 1000 CD in CD player. Vse sem poripsal in dal na zunanji disk in ga priklopil na Mac mini CD pa v škatle in v klet. Sistem z iTunes in iPhone kot dalincem.CD sem prodal in kupil rDAC. Ko sem se naroèil na Tidal sem oboje tako mojo bazo kot Tdal podtaknil Audirvani, zopet dalinec iPhone. Potem sem CD-je prodal (razen klasike) prodal star gramofon in kupil dober nov gramofon in phono. Tukaj sem sedaj.

Še odgovor na vprašanje. Jaz imam raje sisteme, kjer so funcije razdeljene po enotah. To omogoèa veliko fleksibilnost. Naèeloma naj bi bolje kljubovale èasu so pa dražjie kot pa enote ki imajo združene veè funkcij. Seveda pa je tukaj vprašanje koliko daleè se misliš spustiti v to HiFi igro.

Lp

[LightBit]

Streamer zagotovo zastari hitreje kot DAC, ampak še vedno je lahko bolj praktièno in ceneje v kompletu menjati. Tudi class D ojaèevalci kar zastarijo.

Pa saj avdiofil se navelièa naprav pa mora menjati že zaradi spremembe same.

[joztom]

S kolegom sva si privošèila dopoldansko veselje in preposlušala oba DACa, tako starejšega Bifrosta kot novega Chord Qutest v veè žanrih. Sem že prestar in ne veè tako briljantnega sluha za ocenjevanje vrhunske tehnike, vseeno lahko povem, da se je dalo jasno slišati razliko. Vrhunski sistem iz DAC-a, Audio Research predojaèevalca, dveh monoblokov Quad 306, zvoènikov Quad 57, dveh REL subwooferjev, je trdna podlaga za resen zvok, ki ga posreduje namenski iMac preko networka in Audirvana playerja. Novi DAC je glede na starega, ki mu vsekakor tudi niè ne manjka, za korak natanènejši, pinpoint pozicioniranje inštrumentov in vokalov je opazno, bas je bolj natanèen, suh, nekako globlji in bolj prezenten. AB primerjave pa ne dajo kar direktnega zmagovalca, tudi stari Schiit Bifrost ponuja po drugi strani nekako mesnatejši, živ in polnejši vokal in nekatere inštrumente. Pri novem DAC-u bi si zaželel displaya, ki bi kazal parametre signala, tako pa le barve dveh tipk oznaèujejo razlièe vhode in FIR filtracijo. Tukaj je še veliko za raziskovat in možne so še izboljšave zvoka. Vedno sva poslušala USB vir. Vsekakor je še odprta možnost prilagoditev na boljši, namenski USB kabel in testi razliènih RCA povezav naprej. Ampak prvi test za pokušino, vrhunsko. Za poglobljen test FIR filtrov pa je potreben kakšen dodani tweeter na Quad 57, ki ga proti 10k zmanjka.
Se še spomnim uvodnih tednov na svojem Toppingu, da sem ob prijazni pomoèi soforumašev postavil dokonèno zrel zvok, tako nastavitve za DSD driverje v Foobar2000, Tascam-HR playerju in nastavitve bufferja. Windowsi so malo drugaèni od iMaca.

[submat50]

V test sem dobil vrhunski DAC proizvajalca CHORD in sicer Hugo TT2
z M-dcaler-em. Primejala ga bova s Chord Qtest in Burson
Conductor V1. Vse tri bova primerjala samo kot DAC na sistem z zvoèniki. Hugo TT2 in Conductor V1 imata tudi predojaèevalec za slušalke zato ga bova primerjala tudi to. Uporabljene bodo slušalke Grado SR325e Sennheiser HD660S sem žal že prodal. Tudi Burson Conductor V1 prodajam zato bo test tudi zelo zanimiv. Interkonekt med DAC om in predojaèevalcem je Esprit Beta francoskega proizvajalca. Napisal sem bova, seveda bo svoje mnenje podal tudi Jože.

Veè o Chord napravah najdete na njihovi spletni strani. Kakaša pa je funkcija M-Scalar-ja pa je zelo dobro opisano v naslednjem prispevku. Za tiste, ki ne boste brali celotnega prispevka, na koncu je kratko o M-scalarju.

For audio purposes, as @ProfFalkin has said, we usually refer to “upscaling” as “upsampling” - and sometimes as “oversampling”. These terms are often used interchangeably, although a more proper application of them would be that “oversampling” means sampling at a higher rate than Nyquist for the source signal and “upsampling” means performing a sample-rate-conversion (SRC) from one already-sampled source to a higher rate.
While both “oversampling” and “upsampling” work to solve a similar problem, specifically to make it easier to implement the necessary filters for sampling (brick wall/anti-imaging) and replay (reconstruction), the first is applied at capture time in the ADC and the second by the DAC (though there are some DAC architectures which also do internal “oversampling” earlier in their conversion steps).
If you sample a normal audio signal at 44.1 kHz, which is the CD standard, you need a brick-wall filter that absolutely ensures no audio information is passed to the ADC with a frequency higher than 22,050 Hz (otherwise you’ll get images - i.e. false data - lower in the audio band). If you want a flat response from 20 Hz to 20 kHz, then that means you have to attenuate the input from 0 dBFS to -96 dBFS over just 2,050 Hz. If you oversample the input at, say, 176.4 kHz, for the same audio content, your filter now simply has to go from 0 dBFS to -96 dBFS over a span of 66.1 kHz (88.2. kHz - 20 kHz). Which is a much shallower curve and easier (and cheaper) to engineer reliably.
Remember that the input filter operates in the analog domain as it must occur prior to the signal reaching the ADC!
There’s a decent overview 25 of it, with illustrations and examples, here 25. And I’m happy to get into a detailed discussion on specific aspects of it as needed/desired.
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It is worth noting that many DACs, and in particular delta-sigma designs, already do their own upsampling - whether you want them to or not (though some allow you to choose if it happens, and sometimes by how much)!
Schiit’s entire multi-bit line over-samples (for Yggdrasil it is to 8x … or 8 fs - where “fs” is the base sample rate, so 44.1 kHz input gets upsampled to 352.8 kHz), Chord’s DACs do an even more extrema upsampling, in two stages, for example with DAVE first to 16 fs and then by a further 256 fs.
These DACs also use proprietary filters (“Super Combo Burrito” for Schiit’s line, “Watts Transient-Aligned” for Chord’s for example). A typical filter, built into a DAC chip, might use 256 “taps”. When you see references to “tap length” or “filter length”, each “tap” is a specific conversion coefficient, and the longer the filter the more likely you are to get to conversion coefficients of zero. Higher sample rates require longer filters (more taps) to do this. There is no benefit to having a million-tap filter on raw 44.1 kHz (non-upsampled) content, as the vast majority of the taps will have a zero coefficient.
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From a less theoretical effect, let’s talk about actual application and software - per the questions in the original post.
Upsampling can, indeed, be done in software. In fact for both macOS and Windows, if you set the output rate to your audio device (e.g. via the Audio Midi Utility on macOS) to a higher rate than the source material being played, then the OS will upsample the content on the fly.
This is generally NOT a desirable thing as you have no control over how this upsampling is done, and there are multiple approaches, filters and levels of precision that can be applied, which have different implications and potential artifacts - the built-in OS upsampling generally isn’t as good as dedicated software.
Of note, here, is what happens by default in Android-based systems. Android’s standard audio-stack assumes a sample rate of 48 kHz. Any source material not at a multiple of 48 kHz undergoes sample-rate-conversion. For example, standard streaming content, CD content, and most compressed audio will be resampled from 44.1 kHz to 48 kHz. This is a non-integer conversion, which makes the math and precision much more involved (and critical) than a simple powers-of-two conversion (e.g. 48 kHz -> 96 kHz).
More precise conversions and filters (e.g. an ideal sinc filter) are more demanding in terms of power (batter) and CPU, than is ideal for a cellphone, and as a result those sample-rate-conversion implementations are optimized for power rather than quality. Thus we want to avoid that conversion in the device if we can, and this is one reason why Android-based DAPs sometimes tout having a custom-audio stack to bypass this process.
…
Going further …
On a Mac or a PC, there are myriad ways to do upsampling in software. Many high-end music-player applications allow you to enable upsampling, and they generally implement much more sophisticated schemes than you’ll find built into the OS.
Audirvana+ 10, for example, allows you not only to specific many of the details of how the upsampling is performed, and to what degree, but even allows you to choose between two different upsampling engines, “SoX” (open source) and “iZotope”.
If you want more control, and even more sophisticated approaches, including control over things like filter type, tap-length, noise-shaping (required by all 1-bit, delta-sigma and DSD conversions), then you want to look at "“HQPlayer 12”.
Most conversions, at sane upsampling rates, can be done easily on the fly. However, extreme upsampling and the resulting long, complex, filters and noise-shapers you want to apply there, are VERY processing-power intensive. HQPlayer, for example, converting 44.1 kHz PCM to DSD512, and then using the highest fidelity poly-sinc filter and high-order noise-shaping, will required a dedicated multi-core computer (or significant GPU compute capacity) to work, and even then can have significant startup-latency.
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Hardware up-samplers/filters originated when the required processing was more than was easily accommodated on reasonably priced general purpose hardware/computers. Most of that is now handled by software in the real-world (either on the computer, on a basic DSP chip in the DAC).
Extreme hardware up-sampling, and in particular the necessary filtering and noise-shaping you must apply to get the benefits of it, still requires serious processing power (as per the HQPlayer example above). This is where things like Chord’s M-Scalers come in … as they use a massively-parallel DSP approach to do both the upsampling and then the complex filtering and noise-shaping over very long tap length filters.
The Chord Hugo M-Scaler, which is to my knowledge the most advanced and extreme hardware audio upsampled/filter available, uses an FPGA that provides 740 DSP cores, and utilizes 528 of those in parallel to upsample to 4096 fs before applying a 1,015,808 tap implementation of Rob Watt’s “WTA” filter, and reducing the final output rate to something the DAC can handle (upto 768 kHz in the case of Chord’s newer DACs). And even with such powerful hardware on tap, this incurs about a 1.4 second latency. And the result of this is effectively an ideal implementation of a sinc-filter that optimally recovers the originally sampled data for material up to 44.1 kHz and 16-bits, and gets closer than anything else I’m aware of for higher rates and bit-depths.
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So, short version - you can experiment with upsampling (and filtering) in software. Doing so to a high degree requires special software and powerful hardware. And otherwise you can look at various hardware options, the highest-spec of which is, today, the M-Scaler. From there the rubber-meets-the-road as you start to consider the audible effects of this processing vs. what it means in terms of math, theory and the demands/easements it enables on the actual hardware implementation.

Ĺ e dve fotki. Hugo TT2 z M-Scalarjem:



In Celota:



MatjaĹľ

[submat50]

Še dosedanji vtisi poslušanja. �e bi si lahko za HiFi privoèil tak znesek bi bil Hugo tt2 z M-Scalar-jem pod "must". V tem primeru bi resno razmislil ali potrebujem gramofo, seveda èe izvzamemo obred, obèutek, ki ga doživimo ob pripravi in poslušanju LP-ja. Seveda pa je vprašanje kako bi se odloèil, èe bi imel boljši gramofon in phono.

[ambasador]

Ni poanta kaj je boljše in kaj najboljše. Pomembno je samo ali ti daje užitek in zadošèenje.
�e ja, potem se èimprej losaj gramofonske navlake in plošè. Nekomu boš naredil veselje, sebe pa odrešil ritualov. Notranji mir je pomembnejši od predsodkov, dilem, stalne skrbi in poslediènega avdiofilskega stresa kaj je najboljše.
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Carpe Diem

[luka79]

[dabiblo]

Si kdo lasti ali pa je imel možnost slišati Geshelli J2 (AKM) DAC? Vem, da nima input ekranèka, usbja brez doplaèila ipd. a mene tisto ne bi motilo, ker uporabljam zgolj en input in tisti ni usb.

[ambasador]

uuu, si me spomnil:

Asahi Kasei aka AKM je nedolgo tega predstavil novo linijo èipov:
https://www.akm.com/eu/en/about-us/news/2022/20220420-ak4499ex/
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Opomogli so si po poĹľaru. Italijani komentirajo, da bo trajalo preden se bodo kupci tako masovno zanesli na njih kot je to bilo pred poĹľarom.
Vsi so se opekli, na vrat na nos so morali preprojektirati dac-e v svojih izdelkih, ko je AKM odpovedal.
Prav ta poĹľar je dal vedeti kako tvegano je sloneti samo na enemu dobavitelju. Veliko se jih je potem orientiralo na R2R dac-e, zato da so neodvisni, oziroma nabavljajo material kjerkoli.
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Carpe Diem