| Author | Message | ||
| Gary Stadler (Boogiethecat)
Rating: N/A |
A year or so ago I installed a little "Ipod dock" on my bus's dash that my Ipod sits in, hooked to the stereo. Ran 12 volts DC to the power wires and hooked the audio out to the stereo's aux input. Simple enough... convenient since all I have to do is set the ipod in the dock and away it goes.. But I noticed that it was quite noisy and also every time it changed tunes that there was a lot of disk noise getting into the audio...obnoxious actually... So tonight I figured it out...ground loop! Ground loops are common and nasty little devils in home stereos and studios, and are responsible for most of the hum you hear these days. But I'd never considered a ground loop on a 12 volt DC system. Sure enough, hooking the Ipod's audio ground to the stereo (via the RCA plugs) and hooking it's power ground to bus ground (basically the chassis of the bus) resulted in two paths current can take when the ipod is accessing its disk... one thru the power ground as it should be and another path thru the audio ground which makes nasty noises!! So I cured it in 20 minutes by cutting the audio leads and installing two little line-to-line audio isolation transformers..WHAT A DIFFERENCE !! The sound is pristine now, no more disk noise, and it actually goes a lot louder without distorting. WHOOPEE CLEAN AUDIO !! If you are interested and have a problem similar to this, the transformers are cheap little Mouser parts, P/N 42TM016 at a whopping $1.73 each. I just solder the wires to them and wrap it in tape... simple and effective. The mouser page is: http://www.mouser.com Type 42TM016 into the search box and away you go. These transformers also do wonders for hum in home stereo systems and studios alike... Have fun | ||
| Jim Stewart (H3jim)
Rating: N/A |
Gary, waht did you use for the dock? I have been using the same setup for a year, and its great, have my entire CD collection as well as books on tape etc to listen to. I have the ipod sitting on a small shelf, just under the little toll window, but it seems there might be a better way to mount it. I guess I got lucky, as I have not had the ground loop issue. congrats on figuring it out and fixing it. | ||
| Gary Stadler (Boogiethecat)
Rating: N/A |
I just used the standard Apple dock that I bought with the ipod. There is a firewire/charger cable, I cut the end off and figured out which two wires were ok to hook to 12 volts... away it went...  | ||
| Ed Jewett (Kristinsgrandpa)
Rating: N/A |
Thanks Gary, I have a similar problem with my stereo hooked to my big screen. Now I know how to fix. Ed | ||
| Stephen Fessenden (Sffess)
Rating: N/A |
You can also put your entire collection on a few DVDs amd play them in a DVD CD MP3 Player or a DVD CD MP3 FM AM car radio which is what I have. You can buy tens of thousands of hours of old time radio shows on DVDs. Sometimes I listen to THE SHADOW while driving. It is even less distracting than music. | ||
| akrom Rating: N/A |
Who knows what evil lurks in the minds of men? akrom |