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I just had the W200 installed along with the 701 processor.The installer used the AI-net cable provided to connect the 2 units.If I buy an optical cable I could replace the AI-net cable and eliminate the D/A converter in the HU.At the moment the signal is being converted twice (once in the HU and once in the processor).Will there be a DETECTABLE improvement in SQ if I go this route? My installer sais he's not crazy about optical cables in the mobile envirement, but that he'd gladly hook it up this way if I want him to. Martin
-------------------- Too much of everything is just enough. Posts: 391 | From: Boston | Registered: Oct 2005
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Use an optical cable. It will drastically improve the SQ of that set up. I'd be willing to bet you have some low level hiss right now not using the optical.
Leave the ai-net--it carries am/fm and your turn on. You need the optical for the CD/DVD player.
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Actually both the IVA-W200 and the PXA-H701 have 24bit DAC's.
Here's what you're going to gain:
-Currently you are taking a digital signal from the DVD/CD mechanism and converting it from digital to analogue inside the IVA-W200 using the head unit's 24bit DAC. It is then passed out via the Ai-NET to the PXA-H701, where it goes through an A/D conversion (anologue back to digital). All processing done in the PXA is done in the digital realm but after it's finished it has to go through one more D/A conversion so that it can come out through the 4 volt pre-outs and into your amplifiers.
To sum up it means your signal has gone through 3 digital to anologue (or vice versa) conversions.
Now when you move to the Optical output, here's what happens: The digital signal from the DVD/CD mechanism is transfered out digitally (no noise) all the way to the back of your vehicle to the PXA-H701. All sound processing is done in the digital realm and when complete it undergoes a single D/A conversion using the built-in 24bit DAC, outputing in 4V to the amps.
In this example you have done a single D/A conversion.
Keep in mind though that the AM/FM will still pass-thru the Ai-NET cable since this is an anologue signal to begin with (unless you upgrade to HD Radio with the TUA-T500HD. Also all on-screen processor control of the PXA-H701 will still be transfered via the Ai-NET. So PLEASE do not remove this when adding in the Optical cable.
On the topic of optical cables some installers are still confused thinking that they are actual glass cables, not well suited for the car environment. While you can still get glass cables, the majority are various forms of acrylic and hold up very will in the vehicle, and are often much cheaper.
Hope this helps. Upgrade for sure! For the $10-15 for the cable you will thank yourself...Heck even add a center channel speaker and go 5.1.
Remember with PCM mode and Dolby Pro Logic II you can even listen to your iPod in surround sound!!!
-------------------- I'm so happy, Cuz today I found my friends, They're in my head. Posts: 130 | From: Melbourne, Australia | Registered: Jun 2002
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Now that I'm replacing the 200 with a 205 (the 200 was stolen) where should I buy the optical cable? Do I need one custom made? Also - where can I pick up a short Alpine ai-net cable? Thanks - Martin
-------------------- Too much of everything is just enough. Posts: 391 | From: Boston | Registered: Oct 2005
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pacparts may have the ai-net, if not go to any dealer.
Cable--you can get one at wal-mart, you can spend more and get different ones elsewhere. I've never tested them so I don't know if there is a difference. I use an IXOS cable.
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