Problems with Aux/Bus-In on Sony CDX-M730

I have searched the web and 12volt archives to no avail, and Sony support told me to (basically) piss up a rope.

I have a Sony CDX-M730 CD receiver in my old Integra. The deck has worked flawlessly for the ~2 years that I've had it, but I'd like to use the auxiliary input for my battered iPod. I plugged a standard stereo-mini-to-RCA cable into the deck last night, but couldn't get the deck to switch to "AUX." I checked the documentation (for the deck) more carefully, and it mentions that the CDX-M630 (one step down from mine) has an AUX-IN, and my deck has BUS-IN (curse my rotten luck ;).

I talked to Sony support, and their rep helpfully suggested buying a $100 part (XA300 Aux-In selector - link below), since the "AUX/BUS-IN" on the rear of the M730 will not activate unless it's receiving signal from the BUS CONTROL port on the rear of the deck.

Since I'd rather not spend $100 on this auxiliary controller, I'm hoping that someone with some Sony experience may be able to help. Can I simply jumper the BUS CONTROL connection to fool the deck into activating the aux input? Is there a cheaper source for a product similar to Sony's input selector unit that works with a "BUS System" and doesn't cost $100? Thank you very much in advance.

Colby

XA300: https://servicesales.sel.sony.com/web/productSearch.do (enter 'XA300' in the search box in the upper right area of the page, search by 'Part or Accessory Number')

Sorry to reply to my own post...

Upon some further searching, I found this thread:
https://www.the12volt.com/installbay/forum_posts.asp?tid=12241&KW=sony+bus+system

...which addresses the Sony BUS system and the cables used to activate it. Seems like the only plug-and-go way to do this is to purchase the $100 adapter, which I can't easily do. Does anyone know more about the signals carried across Sony's BUS system and how I might sneak around this? Perhaps finding a junked CD changer and cannabalizing the BUS and RCA connections?

Thanks,
Colby

The only thing I can reply is I too had the same sony deck once before and found the same problem your going thru......I found the "Aux. In" was intended by sony to be for a sony CD changer to be controlled by the H/U. I was trying to set up a video system DVD and screen. I ended up gettin an FM modulator and bring in the signal that way. It works ok for that but I wouldnt recomend it for your Ipod as the sound quality wont be as good as a direct plug in. Let us know what you find out.

-------------
99 F-one fitty
Pioneer Premier H/U
Alpine EQ
Kicker 1200 amp
4 Kicker comp 10s
6 kicker SS65.2 components

the problem you'll encounter is that the actual aux in circuit is essentially a gate and it relys on a data command to tell the gate to open and close.... there really is no way to cost effectively replicate this for less than the Sony adapter would be worth.....

PIE i think makes Aux in adapters that are not only vehicle model specific, but also aftermarket radio model specific.... you may to do a search on their site.....

-------------
Kevin Gerry
Certified Electronics Technician
MECP First Class Installer

Owner/Installer
Classic Car Audio
since 1979

I have the same exact question tellec. I'm thinking about buying my friend's CDX-CA710X which has the same "BUS IN" jacks you're talking about. I'm guessing the "BUS CONTROL" port is some sort of proprietary digital line, so jumping it (or using resistors and such) wouldn't work. Anybody else have any ideas?

Mike

Hello all, I have a Sony MDX-C7900 that has the same BUS AUX Input. While surching for another way I found this:

https://www.discountcarstereo.com/detail.aspx?ID=572

It says it will work and is half the price... What do you think?

Sorry everyone, I didn't read the bright red type that says it requires a cd changer to work... Never mind.