DSD ; ASIO ; Native DSD
Ce stiu eu despre
DSD – link
ASIO – protocol software proprietar, dezvoltath Steinberg pt win XP pentru a “sari” peste detestatul KMIXER din XP (in primul rand la inregistrare pt low latency, in al doilea rand sa evite convesia automata a streamului PCM din 24 in 16 biti si rata de esantionare default pt volum), folosit la inceput de segmentul audio pro si mai apoi adoptat si de o mare parte a producatorilor de placi audio cu pretentii de calitate sursa Includerea streamului DSD in protocol a fost facuta in v2.2 sursa pg 48 ofera descrierea implementarii. In ciuda faptului ca DSD este single-bit cu ASIO se poate transmite in 3 feluri, in pachete de 8 biti per byte sau 1 bit per byte irosind restul de 7 biti, deci impachetat sa neimpachetat – pg 33 A pierdut din teren odata cu Vista si implementarea WASAPI si KS (kernel streaming).
Native DSD – eh, aici m-am impotmolit, nu am gasit o definitie unitara, ceea ce ma face sa cred ca e doar un tool de marketing.
- cei care vand muzica: “We strive to provide listeners with a top quality resource for the best quality DSD Stereo and Multichannel music directly from native DSD recorded music and Analog Master Tapes.” sursa Definitia este eronata deoarece nu exista mixer software pt DSD, toate mixerele pt DSD convertesc streamul DSD in PCM (cu super ultra mega rata de esantionare) iar apoi din nou in DSD pt distributie. Conversia DSD PCM si invers se face cu pierdere de informatie, datorita filtrelor folosite, daca aceaste pierderi sunt audibile e un subiect care este in dezbatere. Partea buna este ca exista si inregistrari DSD neprocesate, dar acestea sunt f rare.
- XMOS – Thesycon (firma acceptata de XMOS pt dezvoltarea/customizarea driverelor pt usb audio bazate pe chipuri xmos) face distinctie intre Native DSD si DSD over PCM (DoP), ce inteleg eu de aici e ca ei an intre driver si player un bitsream dsd, dar nu se spune nimic de partea de transmisie propriu zisa a datelor prin USB …. Mai ales ca DSD nu este cuprins in standardul USB2.0. Deci in cazul lor as spune ca nu playerul software face conversia in DoP ci driverul (din pacate aici nu am nimic care sa sustina afirmatia) sursa Mai mult datele sunt la randul lor transmise in pachete conform protocolului USB.
- producatorii DAC – sunt mai rezervati, ei spun despre device ca este DSD capable/ready sau altii, mai putini, ca suporta native DSD
- la un moment dat se folosea sintagma pentru play DSD fara conversie in PCM
Bufallo III based streamer
1. BBB + Volumio – Debian updated to Jessie, MPD git 0.19.2
2. I2SoverUSB
3. Bufallo III – stereo config
Power source
1. DAC – Placid HD
2. line stage – Placid HD bipolar
3. BBB – linear power supply 5V
Case
Cubox-i
Dupa aproape 4 luni de asteptare a sosit
imagine
1. Set-up a mpd server – http://imx.solid-run.com/forums/viewtopic.php?f=8&t=787
a. To optimize the system, you can also replace NTPd with ntpdate. This one is said deprecated by ARchLinux but fully functionnal. It avoid continuous requests done by NTPd which are mosts of the time uneeded for an audio streamer. The main idea here is removing NTPd, installing ntpdate and using a cron job once a day to update the real time clock.
de scos din rc si pus in cron o data la 2 ore
systemctl disable ntpd
crontab -e
0 * * * * /usr/sbin/ntpd -qg
2. [root@alarmcbi ~]# mount /media/music/
mount error: cifs filesystem not supported by the system
mount error(19): No such device
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)
De vazut de ce nu merge cu cifs
3. Static IP Address – Optional – pt varianta finala
aici este “/usr/bin/ntpd -gq || true”
4. modify /etc/hostname
5. update mpd-conf
6. check alsa samplerate daca merge cu Sox
Good recordings
Diana Krall, live in paris. All of them really
Dave Matthews, any CLA mixed.
Norah Jones, Come Away.
All of the Donald Fagen stuff and this has the eztremes of the spectra, but Its all within range +-
Zac Brown. (The iast two)
Any of the Joe Lavano on Blue Note.
Early Dr. Dre stuff.
—————-
Tube vs SS
Dintr-un review:
One reason audiophiles (and musicians) like
valve amplifiers is that they overload very
gracefully… so gracefully that it’s difficult to
perceive they’re overloaded at all. Whereas
solid-state amplifiers go straight into hard
clipping at which point they suddenly
generate (literally) hundreds of high-level
odd- and even-order harmonic distortion
components, valve amplifiers clip ‘softly’
and, when they do, generate only a few,
low-order harmonic distortion components,
many of which sound so pleasant to the ear
(being predominantly low-order and evenorder
harmonics) that it’s difficult (perhaps
impossible) to hear they’re overloading at
all. This ‘soft clipping’ effect also makes it
difficult to measure the exact output power
of valve amplifiers, because soft clipping
is also difficult to observe visually on an
oscilloscope screen, whereas hard clipping
is instantly visible.
DAC – o noua abordare
La momentul in care am aflat de noua abordare a DAC-urilor de la Chord s-au aprins niste beculete (de fapt ei au inceput cu DAC64)
A fost primul DAC care nu folosea un chip DAC per se, denumirea tehnologiei aleasa de ei a fost The Pulse Array DAC. Read More →
Filtre de reconstructie ce (nu) fac ele si de ce
un exemplu vizual foarte bun.
http://www.diyaudio.com/forums/pc-based/251845-over-sampling-44-1khz-wav-files-4.html#post3840374
REW
De obicei in momentul inca care ajungi acasa cu noile boxe ai impresia ca parca nu ar suna la fel ca in show room, dupa cateva zile esti sigur ca nu suna la fel si atunci incepe distractia. Incepator fiind in ale HiFi-ului m-am apucat sa studiez problema. Dupa nenumarate articole/posturi pe diverse forumuri in care se laudau calitatile incontestabile ale cablurilor interconect, apoi cablurilor de alimentare, sau a power conditioner-elor presarate cu catifelari ale sunetelor si noi detalii aparute din senim la piese ascultate de zeci de ani am inceput sa ma indoiesc de bruma de fizica pe care o invatasem in liceu.
Dar pe ici pe colo mai aparea inca o sintagma prepararea camerei de auditie, bass trapuri, difuzere si alte minunatii. La un moment dat am dat peste un articol care se intitula Is the rooom lying to you? sau asa ceva in care se explica faptul ca de fapt boxele + camera formeaza un singur sistem si nu numai boxele. Cool, dar ce aveau oamenii aia prin camerele lor de auditie nu prea se potriveau la mine in sufragerie si in ciuda faptului ca am noroc de o sotie cu WAF mare, totusi ma vedem mutat in curte impreuna cu sistemul audio si bass trapuri in cortul de 4 persoane. Asa ca aveam nevoie de o abordare mai subtila :). Pfff D.R.C. (Digital Room Correction) scria pe mine, in mintea mea asta rezolva totul cu minimul de impact vizual asupra camerei.
Sistemul curent
| Music Server(s) | 1. fanless pc, no hdd, custom debian mpd on USB sitck 2. BBB + Hermes + Cronus + Buffallo III 3. wandboard quad / cubietruck / Raspberry Pi 2 B |
| Music Server Operating System | Linux |
| Preferred Digital Interface(s) | USB |
| Digital to Analog Converter(s) | 1. BBB + Hermes + Cronus + Buffallo III 2. JLsounds.com AK4490 3. ESS9018K2M based dac diy 4. Audiobyte Silver Dragon 5. JLsounds.com AK4396 powered by 2 x salas SSLV 1.1 BiB diy 6. Subbu DAC V3 SE – diy |
| Digital to Digital Converter | Stello U3 – I’m using it now just for comparative tests or to break ground loops when necessary |
| Preamplifier | none |
| Amplifier(s) | VTL IT-85 |
| Loudspeakers | JMR Offrande Supreme V2 |
| Interconnects | standard USB2 certified cable DIY interconnects: Bluecord 300-silver + Neutrik NF2CB2 |
| Loudspeaker Cables | Neotech KS 1226 |
| Power Cables: | DIY: NKG 310 |
| Remote Control Apps | ncmpcpp ; MPDroid |
| Miscellaneous | power conditioner – Effekta MKD 2000 -Series |
| Headphones | Sennheiser HD650 |
| Headphone Amplifier(s) | 1. The Wire SE-SE diy 2. The Wire BAL-BAL diy – under construction (sold – Bottlehead Crack + Speedball + various tubes2 – diy) |
| Turntable | Technics SL 1210 – currently stock |
| Phono Preamp | Salas Folded Simplistic Phono PCB |
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