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Old 17th March 2009, 10:16   #46
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Quote:
Originally Posted by DerAlte View Post
Is there really a problem if analog signals are switched?
Not really. The only problem is that the much advertised and abused "24 Bit DAC" doesn't really come in play if you use your iPod or USB as a source.
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Old 17th March 2009, 10:59   #47
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There's a DAC in a thumb drive?
Now which thumb drive has the best one?
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Old 17th March 2009, 11:02   #48
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Gunbir, is there a hack to make the HU use the DAC for the CD, while the source is USB?
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Old 17th March 2009, 11:06   #49
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Originally Posted by gunbir View Post
Not really. The only problem is that the much advertised and abused "24 Bit DAC" doesn't really come in play if you use your iPod or USB as a source.

eh?? so then what DAC does the HU use? Paaji I think the DAC definitely comes into use there, and I doubt they would have an inferior DAC just for USB. It would be expensive and useless
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Old 17th March 2009, 12:03   #50
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Originally Posted by gunbir View Post
Not really. The only problem is that the much advertised and abused "24 Bit DAC" doesn't really come in play if you use your iPod or USB as a source.
That is the strange part - difficult to visualize the designers' p-o-v since it really does not involve silicon real estate (or rather, there is available silicon real estate which needs to be used intelligently).

This is where the old 'controls' world differs from the 'computer' world in design philosophy. The default choice is obviously reusing blocks / components (hence the preference for analog switching). However, if you look at the modus operandi for feeding the DAC, the objective is to keep it fed via a buffer.

Current implementations have a hardwired byte dump channel from the CD drive. If only the on-board controller in the HU has a way of getting the USB channel to dump into the same buffer. Unless that buffer sits on the data bus, where all the other digital sources are located, one will not be able to route other byte streams to it.

All 'file'-related work gets done over that bus, i.e. directory scan, file open/read/close, messaging to sub-systems (like iPod). Since the default expectancy is of compressed data stream (mp3 etc.), the stream is routed to the hardware codec over the bus. If that DAC is on this bus (can't figureout unless I see a schematic) then everything (other than Tuner and Aux-in) gets played through it.

One would have thought the "full speed" iPod link would be appearing in the same route. Doesn't it? "Full speed" doesn't make sense if iPod's codec is in the picture, whereby one is routing the analog signal from the iPod (there are pins for it in the iPod connector) to the HU.

Last edited by DerAlte : 17th March 2009 at 12:07.
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Old 17th March 2009, 13:11   #51
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Originally Posted by gunbir View Post
AFAIK currently no HUs support WMA Lossless... I suggest sticking to WAV files.
You are right! The manual says it can play WMA upto 320Kbps, and MP3/AAC upto 320Kbps-VBR. BTW, doesn't' WMA has something like VBR?

My earlier comment was based on something that I got from their website, which looked something like this (in a feature chart):

Support for
WMA7,
WMA8,
WMA9,
WMA9.1
Lossless
voice: Not
support

I think I interpreted it in a wrong way, probably either "Lossless voice: Not support" or "WMA9.1 Lossless voice: Not support" is to be read as a single line while other formats are "supported" ones! Not only that, the document was related to 786 model not 785 that we are discussing about. Many time when looking for something, I tend to be too optimistic, you see
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Old 17th March 2009, 13:19   #52
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Regarding internal signal switching: I wouldn't care soooo much about the DAC part, but if they use different DACs and analog switching, then how do they handle processing like bass/treble, parametric EQ, TA? I hope all these processing features are NOT source specific! Don't tell me that it will work only for CDs, and not for USB/Radio (Like s/w audio players which support EQ only for MP3s but not for WAV/CD!). TA is the biggest attraction in this HU for me, and I expect it to work uniformly irrespective of what I am listening to!
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Old 17th March 2009, 13:20   #53
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Quote:
Originally Posted by gunbir View Post
In case of USB, usually the inbuilt DAC on the USB receiver chip is used.
So if a HU has 24 bit DAC for the cd , the same will be used by the USB.

And with the aux - in?
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Old 17th March 2009, 13:23   #54
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Yaar santosh. the DAC just converts the Data to Analog signal. the processor does the TA. so nothing to worry about. i have a 9887 and i play the ipod off it, and TA makes a huge difference.
bottom line: TA works for USB,CD and iPod!
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Old 17th March 2009, 13:24   #55
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Sorry for multiple posting, but I have another important question-
Gunbir, are you sure that this HU plays alteast WAV files as a lossless option from both CD and USB/iPod? I am asking because it's manual doesn't say anything about WAV as such. I read somewhere that it the default (may be because it very much same as playing normal CDDA disks), but I also read that latest models of a popular brand (probably Kenwood) has DONE AWAY with WAV support! If so, it will be another shocker! (I don't see what they save by not supporting WAV playback)

Last edited by santosh.s : 17th March 2009 at 13:26.
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Old 17th March 2009, 13:24   #56
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Quote:
Originally Posted by abhinav.gupta88 View Post
So if a HU has 24 bit DAC for the cd , the same will be used by the USB.

And with the aux - in?

AFAIK, the aux in is already an analog signal. no need to go through the DAC. someone please correct me if im wrong!
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Old 17th March 2009, 13:24   #57
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Quote:
Originally Posted by santosh.s View Post
Regarding internal signal switching: I wouldn't care soooo much about the DAC part, but if they use different DACs and analog switching, then how do they handle processing like bass/treble, parametric EQ, TA? I hope all these processing features are NOT source specific! Don't tell me that it will work only for CDs, and not for USB/Radio (Like s/w audio players which support EQ only for MP3s but not for WAV/CD!). TA is the biggest attraction in this HU for me, and I expect it to work uniformly irrespective of what I am listening to!
I think the TA function works irrespective of the source.

Thats also my sweet spot for this HU.
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Old 17th March 2009, 13:34   #58
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Originally Posted by frankmehta View Post
Yaar santosh. the DAC just converts the Data to Analog signal. the processor does the TA.
If it is possible that for some reasons they pass digital streams from CD and USB through different internal channels and DAC, then it is also likely that processing is done only for select channels and not for others. That is my concern. All such things seem counter intuitive, though. I don't think a reputed brand can afford to cut corners like that, but you never know!
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Old 17th March 2009, 13:39   #59
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Damn so how many people are actually getting this HU
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Old 17th March 2009, 14:17   #60
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i guess about 9075908938574 of them since everyone is talking about them nowadays! i'm responsible for quite a few of them.. HEHEHE!
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