My goal for 24 bit-perfect portable setup:
iPad with no jailbreak and no DIY hardware mods
Server/player easy to setup and start with at least cover arts and auto play next (gapless not indispensable)
High storage capacity (500GB+)
Internet connection or router not required to work
CCK/USB DAC or dedicated DAC/Amp
All battery powered
iPad has limited storage capacity, which must be addressed for those big 24 bit files.
Apps which play local stored files (stock player or Flac Player for usopported format) are less useful and if you add storage to the dock out you can't output digital files to an external DAC.
REMEMBER: Any point in the chain could downsample data: HW, server software, settings, player and iDevice used all do matter.
For portability of some sort, until now the iPad is the only iDevice (without jailbreak) confirmed working without downsampling 24 bit / 96 Khz files in any point in the chain and only under specific configurations that I'll recap here:
1) Camera Connection Kit (older iPads) or the newer Lighting to USB Camera Adapter.
2) 24 bit USB DACs that don't require a driver to work at 1.1 USB specs and must provide power via USB PORT.
3) USB Hubs battery powered, powered with portable USB battery chargers or iPad powered (20mA MAX), if the USB DAC works driverless but do not provide power via USB port.
4) Specific server/iPad player combos. For portability everywhere we need a portable battery powered high storage wi-fi UPnP/DLNA server (500GB+) with bundled software player (or able to use a third-party app) capable to stream 24 bit-perfect data. For portability at home there are more choices, that I'll recap later.
Points 1), 2), 3) are potentially addressable with a dedicated DAC for iPad similar to:
Cypher Labs AlgoRhythm Solo (DAC only) officially supports 24 bit for iPad only (see page 7 of the FAQ not the manual), but needs to be confirmed by users, testing its own digital coax out to an external dac able to display bit/samples effectively received.
CEntrance HiFi-M8 (DAC/Amp combo) officially supports up to 192Khz, but I think only 96Khz for iPad, without digital out can't be tested with an external DAC able to display bit/freq.
Sony PHA-1 (DAC/Amp combo) officially supports up to 24/96, but without digital out can't be tested with an external DAC able to display bit/freq.
There are a lot of other dedicated DACs for iDevices, but they're limited at 16 bit / 44.1 KHz.
Point 1): without a dedicated iPad DAC you need a CCK or the newer LtUSBCA to use USB digital audio out from iPad.
For Point 2) be careful that not any powered USB DAC/Amp works, since we have two problems to solve, it needs to:
a) work driverless at USB 1.1 specs (= up to 24bit/96Khz).
b) the USB PORT of the DAC must provide power, IF NOT, a USB HUB is always needed (see Point 3).
Since latest iOS iPad always checks for power req of the device asking data (USB DAC) indipendently if it's powered or not.
Example 1: the M2Tech Young DAC is a powered desktop USB DAC, but it works only with drivers, so it won't work with iPad/CCK USB out.
Example 2: the iBasso D7 portable USB DAC/Amp isn't powered and iPad is unable to power it, but it works driverless at USB 1.1 specs and adding a USB charger and USB Hub it works.
Example 3: the Antelope Zodiac is a powered desktop DAC, it will works up to 384Khz with drivers, but also up to 96Khz driverless and it has a powered USB port, so it'll works without the need for a USB Hub.
Note: some USB DACs that works are unable to process any sample rates up to their max supported (96 max but no 88.2 or 192 max but no 176.4 Khz support), it depends on the USB chip and number of clocks installed.
I'll list here any portable battery powered 24 bit USB DAC/Amp (none so far) or unpowered but working (see point 3 for details) up to at least 96 Khz and which are not dedicated to iDevice only:
Meridian Explorer up to 192Khz + point 3).
iBasso D7 up to 192Khz but not 176.4Khz + point 3).
CEntrance DacPort up to 96 Khz + point 3).
Audioquest Dragonfly up to 96 Khz, reported working without point 3) but still to be confirmed with latest iOS firmware.
Schiit Modi up to 96 Khz, reported working without point 3) but still to be confirmed with latest iOS firmware.
HRT microStreamer up to 96 Khz, reported working without point 3) but still to be confirmed with latest iOS firmware.
For Point 3), if the USB port of the DAC doesn't provide power for the attached device (so to pass iPad power check), we need a USB Hub battery powered, powered by USB battery chargers or directly powered from iPad/CCK up to 20mA MAX (the last one is now avaiable and the best solution). USB Hubs by definition pass data and power via each USB port.
Most USB chargers are not Hubs, data pins are not connected so they provide only power; a few are able to pass data exclusively via USB OUT (not via mini USB IN used to recharge) so at least two USB OUT are needed (1x iPad, 1x USB DAC) making them real Hubs.
The old solution to use a USB Y cable (one of the three ends is power only) to provide power to the USB DAC doesn't work anymore, with the latest iOS, iPad will check power requirements of the device asking data (USB DAC).
Only a USB Hubs in the middle do the trick and activate iPad USB digital out: if the USB Hub is powered any USB port will provide power; if the USB Hub is unpowered it must work at 20mA MAX to be powered directly from iPad (like Unitek USB Hub cable).
I'll update the list here of USB Hubs battery powered (or USB chargers with at least two USB OUT) or directly powered from iPad/CCK up to 20mA MAX which are the most interesting:
Unitek USB cable with Hub: powered directly from iPad/CCK USB out, is avaiable with different connectors to USB DACs (USB female, male mini USB and male micro USB) the male USB-A connector must be plugged to iPad/CCK.
Thanks to whodiini for suggesting this USB cable + Hub.
The US eBay link is http://www.ebay.com/itm/USB-2-0-90-degree-angled-male-to-2-female-extension-data-hub-rainbow-color-cable-/110855033353?pt=US_Video_Game_Cables_Adapters&hash=item19cf799209. If you are in eBay Italy just search "prolunga USB HUB" and you'll find plenty.
Also check seeteeyou post #85 at page 6 in this thread for additional links to various types.
On Lite H420B: 4 rechargeable batteries that you can change/add at will (NOT WORKING RELIABLY).
D-Tech solar/battery powerd USB Hub (4 USB, 1 mini USB): solar power not capable to feed USB DAC/Amp, battery last 1 hour max.
Tekkeon MP1860A (2 USB OUT, 1 mini USB IN) USB charger + data pass (still to be confirmed).
For Point 4) and portability everywhere we need a portable battery powered high storage wi-fi UPnP/DLNA NAS (500GB+) with bundled server software and player (or able to use a third-party app) capable to stream 24 bit-perfect data.
Seagate GoFlex Satellite (now bettered by newest Seagate Wireless Plus 1TB) works with bundled software, it does not transcode/convert files and is able to stream any files the device supports or files supported by third-party apps like 8player. It has some DLNA capability (but not fully certified).
Buffalo MiniStation Air (500 GB) not yet released and incomplete infos, will come with its iOS dedicated app.
Patriot Gauntled Node (hard disk not included, you can choose storage capacity), is confirmed not working bit-perfect with bundled software (zzffnn reported working with SAMBA streaming which, even if bit-perfect possible, is rouled out=long start up time, too long loading each file, no cover art, no background play, no browsing while play,...).
I'll update the list here:
Seagate Wireless Plus (1TB)
Seagate GoFlex Satellite (500GB, latest FW can use internet while streaming) discontinued.
For Point 4) and portability at home we have more choices since there are lots of server software avaiable built-in a NAS or a computer system.
My favourites are:
a) Logitech Media Server + iPeng Player (audio only. In-app purchase needed, no need to have a Logitech device).
b) Twonky Media Server or any similar DLNA/UPnP server + 8player.
c) iTunes Home Sharing + stock player (audio/video but only for officially supported iPad formats).
All setups are tested using external DAC able to display bit/freq received and which does not resample incoming data.
iTHS/stock iPad player isn't a good solution: limited formats support and a really bad interface.
For music only, LMS/iPeng is the best configs right now: great sound quality, FLAC support (no need to convert files neither in the server), cover arts in any directory, better browser organization and faster interface,... Sound quality differences are not strange since any software player do something in a different way (JRiver, Foobar, WMP, iTunes, JPlay,...): bits are not just bits in digital audio, "time" matter a lot.
BUT iPeng officially will never support UPnP/DLNA and LMS is not installed in any portable battery powered wi-fi server.
The solution for UPnP/DLNA servers streaming 24 bit-perfect data with support for all audio/video formats is to use 8player. Don't bother with any other app since until now most won't work bit-perfect, have bad file support and miss fundamental features (background play, play while browsing library, play on the fly, auto play next, cover arts,...). You can use 8player with the Seagate GoFlex Satellite (UPnP/DLNA wi-fi battery powered server) for audio/video portability everywhere. But I'm still unsure if FLACs are bit-perfect, since the displays stick with last ALAC played regardles FLACs bit/freq played.
A solution at home is to instruct the server to transcode FLACs to WAV and you've a bit-perfect setup without converting FLAC files.
Remember, most UPnP/DLNA iPad players won't work at 24 bit-perfect audio data:
PlugPlayer or AceMusic players for example always downsample regardless of wi-fi type, streaming server settings and configs used.
I'll update the list here for any UPnP/DLNA iPad player working 24 bit-perfect and have most fundamental features:
8player (even if not transcoded in server, FLACs play but still unsure if bit-perfect)
Other iDevices (without jailbreak) are generally limited to a max official support of 24 bit / 48 Khz, which could be fine, but without a CCK, you need a desktop digital dock which is not portable neither at home or a dedicated iDevice DAC/Amp.
iTHS/stock Apple player is limited to 16 bit for iPhone/iPod touch.
LMS/iPeng officially support 24/48 for iPhone/iPod Touch, but needs to be confirmed.
Cypher Labs AR Solo supports 24 bit for iPad only, but could works, a direct test needed from its digital coax out.
Sony HPA-1 supports up to 24/96 but it's uncertain if it's for iPad only and without a digital out it's impossible to check.
Fostex HP-P1 was potentially a good choice (32 bit DAC/Amp combo) but it's limited at 16/48 and iPad not even supported (even if reported working at 16 bit).
iPod Classic 160GB (without wi-fi and third-party apps) works with 24 bit / 48 Khz files only in the sense that it'll be able to play them but it will always downsample to 16 bit before reaching the DAC section.
VentureCraft Go-DAP 4.0 will always downsample to 48Khz (thanks to AnakChan for reporting).
I'll update any possible portable 24 bit solution for other iDevices here:
I know iPad + CCK + USB Hub + USB DAC/Amp + mobile storage wi-fi isn't really pocketable for jogging, but at least is a transportable 24 bit system with a normal iPad/notebook bag.
iPad, Seagate GoFlex Satellite, iBasso D7, B&W P5 headphones and all cables/adapters fits inside my iPad bag.
The cable connecting the USB charger to USB Hub and USB DAC, is an USB Y split cable with the power only end versus the charger.
Use any portable USB charger with the Unitek USB Hub cable to have a very portable config that last as much as the USB charger allows.
This is a comparison picture between the iBasso D7 and my newer high-end Meridian Explorer which sounds better in every parameter and is more pratical with an analog volume controlled digitally inside any player (no more need to reach the amp knob and it could stay inside the bag).
Last thing to note: Power direction do matter. DO NOT use a USB male/USB male cable to connect the USB charger to the USB cable Hub (picture below) since the batteries do not last as much as having an USB Y split cable with the power only end attached to the USB charger (picture above).
Maybe in the wrong method the charger feed power to the USB Hub cable and iPad too, the result is less batteries duration.
Supposedly in the right method the USB Hub cable is low power enough to be feeded by iPad itself and the charger is reserved to USB DAC only so batteries last longer.
Edited by Thraex - 11/16/13 at 3:55am