posted
I was wondering if anyone had any links or info on how to integrate an aftermarket 20-bit DAC (like the McIntosh or Nak ones) with a factory head unit? Is this even possible? If it is possible, does the factory CD changer also go through the 20 bit DAC, or do the changers have a built in dac?
I know that the Mac and Nak 20-bit DAC's have both co-axial or fiberoptic inputs, so I guess the challenge is too some how tap into the factory deck.
I have a Acura Integra, and want to keep the stock radio (for theft reasons), but I have no idea in where to even start looking in how to do this. Can anyone help??
Posts: 20 | From: Bay Area | Registered: Oct 2001
| IP: Logged |
posted
In theory it is pretty simple to do. Locate the digital signal from the transport going to the DAC in the HU. Put in a Toslink connector, or just connect a regular RCA there for coax. The signal coming from the changer is typically also analog so you would have to do the same thing there too. The problem is finding the proper pin onthe DAC chip that is the digital signal. Most headunits uses house numbered ICs in them so you can't easily find the pinout. But given enough time you can generally figure out what you need to tap into.
Posts: 2575 | From: GA | Registered: May 1999
| IP: Logged |
posted
thanks for the reply. So would the digital signal coming from the transport be only 2 wires, since all you need is a regular RCA? Or would it be 2 wires per channel, for a total of 2 RCA's that are needed? Also, what is a Toslink?? Do you know of any sites in where I can study up on this stuff? Thanks again!
Posts: 20 | From: Bay Area | Registered: Oct 2001
| IP: Logged |
posted
The digital signal is carried on a single channel RCA. The RCA carries the digital signal and ground.
Toslink is a format developed by Toshiba for carrying digital audio signals optically. The electrical signal is converted to light and carried on an optical cable. Toslink is what is on almost every piece of audio equipment that has an optical digital input. The benefit to Toslink over some companies proprietary formats is that you can buy the needed cables almost anywhere.
Both coax and Toslink have the same signal format which is SPDIF (Sony Phillips Digital InterFace) which is what consumer digital audio uses. This is how the information is coded on CDs, it has left signal, right signal, and control information for every sample, 44,100 times per second.
There are benefits/disadvantages to optical and coax. It would be easiest to do a coax, but not too much harder to do a Toslink connection. If the DAC you have will do automatic switching depending on which input has a signal you could mod the HU for a Coax, and the changer for optical, and the DAC would switch between the two depending on which was playing at the time.
You will lose the ability to listen to the radio if you do a digital output, becuase the radio signal doesn't go through the DAC. It might be possible to build a custom ADC to convert the radio to digital, and a switcher so that you don't lose the radio.
I'll try to find some more sites that explain some of this stuff.
posted
Whoa, that's a lot of info. Thanks for the replies jc2! Some sites would be awesome!
Posts: 20 | From: Bay Area | Registered: Oct 2001
| IP: Logged |
posted
This is what I was going to do. I was going to use a Sony optical switcher - to get around the radio issue - I was going to use a cheap Radio Shack a/d to coax/toslink converter, and put it into the switcher, as JC use a coax or toslink for the changer and headunit. Put the switcher up front and run the toslinks all the way to the back (trunk) and then convert it back to analog (less noise by the trunk). Run it into an IDX 24 and then into your amps. As far as headunits - Little Wing (on this forum-/ Voodoo Chile on SOunddomain has a 7049 for 275-this unit is cost effective and has a optical out. You could also use a monitor and changer as well i.e. Clarion 8271, Alpine cva etc.) I would suggest the MDA 5000 since it 24 bit - to be most cost effective pick up a Monarchy/ Perpetual/ MSB link external DAC that runs on 12 volts from Audiogan.com classifieds and has HIGHER quality than ZAPC DAII/ Orion DEQ etc. (IMO).
Posts: 93 | From: NJ | Registered: Nov 2001
| IP: Logged |
Printer-friendly view of this topic