nb skrev:
Videoprossesering er high-tech. Gi balla i de kjente Hi-end HiFi-merkene. De må uansett kjøpte nøkkelteknologien fra noen som vet hvordan det gjøres. Ref Goldmund Eidos Reference Blue, kanskje fjordårets største spøk, eller Lexicon som er Oppo puttet inni et annet kabinett og prisen ganget med 7 eller deromkring. Theta er også Oppo. Do the maths,.
Theta skal ha gjort en del mer med sin ombygde Oppo enn det Lexicon har (som vel knapt har gjort noe annet enn selve kabinettet). Den ligger på USD 3k. Mens Ayre har tatt den enda lengre ut og vel bygd om alt unntatt selve bildeprosesseringsdelen. Den ligger da også på høye USD 10k. Men det er i hovedsak på analog delen i spillerne det er gjort forbedringer. Charles Hansen i Ayre har vel også innrømmet at det hovedsakelig er for Audio bruk det er mest å hente. Derfor tror jeg mange av de som kjøper disse som filmavspiller - og som på toppen av det kun vil bruke HDMI kabel til surround prosessor - betaler for mye de aldri vil benytte.
Jeg tror at disse spillerne mest er rettet mot custom install markedet eller mot kunder som sverger til å ha alle komponenter innen ett og samme merke. For majoriteten her på forumet har man vel andre primære lydkilder enn en BD spiller og da vil Oppo´en være mer enn god nok. Må her legge til at Oppos versjon, Oppo BD 83 SE, har imponert meg mht. lydkvalitet på de analoge utgangene. Jeg bruker 7.1 utgangen til multikanals SACD og DVD-A og det låter særdeles både luftig, dynamisk og stramt.
Når det kommer til bilde er jeg personlig ikke i tvil om at en Oppo med HD-SDI og videoprosessor knuser hvilken som helst av disse andre Oppo-baserte spillerne med HDMI når det kommer til SOTA bildekvalitet. En HD-SDI modifisert Theta eller Ayre bør vel være en annen sak...
Her er forøvrig info om hva både Theta samt Ayre har gjort med sine spillere basert på Oppoen (sakset fra AVSforum):
THETA COMPLI BLU
1.Heavy 16 gauge steel chassis for rigidity.
2.Positions of transport mechanism and display have been swapped. Lowering the mechanism allows for elimination an intermediary mounting bracket and long standoffs, resulting in greater rigidity.
3.Completely rigid mounted mechanism replaces the original spring mounted system.
4.Special 3M adhesive damping material used on drawer assembly, further reducing vibration energy.
5.RS-232 control is included as a standard.
6.Custom designed front panel PCB.
7.Custom designed analog power supply, which includes the following:
A. An 80 Watt ultra-quiet toroidal transformer.
B. Additional, independent 10 Watt transformer for Standby circuit.
C. A total of 7 Amps of power available to supply the unit.
D. Four independently rectified and regulated power supplies.
E. Over 40,000 uF filter capacitance, in small, low ESR multiples.
F. 2 oz. gold plated copper used throughout.
8.Proprietary Theta Digital customized software for superior performance, and that can be easily updated through USB port on the rear panel, or via Ethernet connection to Theta Digital's website.
9.Standard thick, brushed aluminum alloy cover provides better sonics and aesthetics as it reduces vibration energy further.
10.1/2" thick Tower and Faceplate matches other Theta Digital products.
NB! Theta spilleren har ikke to HDMI utganger.
AYRE DX-5
To make it an Ayre, we dismantle it completely and recycle everything except the main PCB (with the video decoder, ABT scaler chip, and HDMI transmitter), the transport mechanism, the VFD display, and the remote control handset.
Next we re-build the main PCB. The big switching power supply only provides 5 VDC, then there are little mini-switching power supplies (called DC-DC converters) on the main PCB that turn the 5 VDC into 1.0 VDC, 1.1 VDC, 1.8 VDC, and 3.3 VDC. All of those are removed. There are also USB power switches that allow hot-plugging of USB devices. These are removed as they have another kind of DC-DC converter called a "charge pump".
All of the supplies are replaced with pure linear supplies with analog regulators. The USB power switches are replaced with devices without the charge pumps. Now we have gotten rid of seven noise sources that create high-frequency square waves with harmonics well out into the MHz region. Getting rid of all of that noise creates a visibly cleaner picture.
Next, we replace the low-quality master video clock with a VCXO. This becomes more important later on, as you will see.
Now we start adding things back in. First is our AyreLink communication system. It allows AyreLink equipped components to act as one big system. For example, turning on the player will turn on all of the downstream components as well as automatically select the correct input on the preamp. We also make an external RS-232 to AyreLink converter box for system controllers like Crestrons. The AyreLink system has opto-isolators between each component to avoid unwanted ground loops, which is why we don't use RS-232 inputs on any of our equipment.
Then we add a custom programmed FPGA on the front panel PCB to do some housekeeping. It intercepts the appropriate commands and translates them to operate the AyreLink system. It disables the internal volume control (which operates in the digital domain and degrades the sound) and instead routes the volume changes to an AyreLink equipped preamp. It also allows us to send custom messages to the front panel VFD display. So when the USB audio input is activated, it will report that on the front panel along with the sample rate of the received signal.
There are a bunch of boards added on the audio side. I say "side" because we literally split the player into two parts. There is a separate power transformer that runs all of the audio circuitry, which is separated from the video side by a bank of opto-isolators. So the audio and video "sides" have separate grounds that are completely galvanically isolated. This is the only way to get the best performance from either your audio system or your video system.
All video displays have switching power supplies that dump noise into your system in the absence of such isolation. There are also ground loops that are inevitably formed as there is no such thing as a balanced video connection. All of those problems go away with our isolation system.
The ten-channel audio board is replaced by a two-channel audio board. Everything on this board is top-quality, with discrete, fully balanced, zero-feedback audio circuitry and discrete, zero-feedback power supply regulators. There are improvements in both the parts quality and circuit design that give it even higher performance than the QB-9 USB DAC that was recently rated "Class A+" in Stereophile's recommended components issue. For two-channel disc playback (CD, SACD, DVD-Audio), the performance exceeds our $6,000 audio-only disc player.
We also add the USB audio input that allows you to connect your personal computer and turn your system into a music server. Your entire digital library (except SACD's, thank you very much Sony -- not!) can be stored on a hard drive and played back with the click of a mouse. So this one component can be the only source component that you need. This input is also connected via a bank of opto-isolators, so there is actually a *third* "side" to the system -- the video, the audio, and the computer. The noise from your computer and its switching power supply will not be connected to either your video or audio systems.
We also add a second audio-only HDMI connector. This is fed by the isolated signals on the audio "side" so that it won't contaminate your surround-sound system if you choose to connect one. It also supports the new "Audio Rate Control" (ARC) feature that is part of the HDMI 1.3a specifcation. This is a breakthrough for the surround-sound enthusiast, as HDMI is normally the worst way in the world to send audio data -- the jitter is even worse than the lowly S/PDIF connection.
But with ARC, the surround-sound processor uses a local crystal oscillator to provide a low-jitter clock to the DAC chips. Then there is a buffer that stores the incoming audio data. When the buffer is too full it sends a signal back upstream to the Blu-Ray player telling it to slow down the disc slightly. When the buffer is too empty, it asks the disc to speed up slightly. Now the audio clock is in charge, the way that it should be. (When the unit is running in two-channel mode, the local low-jitter, fixed-frequency crystal oscillator provides the master audio clock.)
With a modern digital display (plasma, LCD, LCOS, DLP, et cetera) jitter on the video signal does not matter. Since there is no conversion to analog, the digital signal values are simply stored in a frame buffer until needed.
Then the whole thing is put into a custom chassis made entirely from anodized aluminum and stainless steel.
