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View Full Version : Measuring Preout Voltage on an HU



Paaco1981
04-12-2008, 03:08 PM
This week I cranked up my truck, had bass for about 10 seconds, then nothing. It wasn't even turned up or anything. Volume was probably on about 4 or 5. I believe the preouts on my HU quit working but I'm not 100% sure that I am measurin g the voltage correctly. If I put the leads on my DMM on the center pin and outside edge of the end of my RCA's on AC voltage I get a reading of 0. Am I doing this correctly?

Paaco1981
04-12-2008, 04:17 PM
Someone has to know a way to test the Preout Voltage on an HU :( My HU is a JVC Arsenal 880. 5V Preouts.

ebrunn
04-12-2008, 05:19 PM
Anyways; you'd grab a DMM and set it to volts AC, stick the DMM's red lead on the inside of the RCA preout, the black lead on the outter shield of the RCA preout, play a 0db sine wave and read what the display tells ya. Also keep in mind that, with only a DMM, you won't be able to monitor the point of clipping.

.....

Paaco1981
04-12-2008, 06:12 PM
Thanks Ebrunn, I was doing it correctly. I guess my HU just quit sending a signal to the RCA outputs :( It's still under warranty, time to send it back I guess.

skmfkr
04-12-2008, 06:16 PM
your cd player has to be at max volume for it to read 5v. best way to do it is turn the volume all the way up when you test it.

Paaco1981
04-12-2008, 06:29 PM
I had it about half way up on a 50hz test tone and it was showing 0 voltage. Even if it doesn't show the 5 I should have been getting something :( Thanks for the help guys, guess I'll have to warranty it.

I thought it was probably the amp at first. Kinda glad it's just the HU. My T20001bd isn't still under warranty :)

ebrunn
04-13-2008, 12:34 AM
http://www.icixsound.com/vb/showthread.php?t=11797&highlight=preout+voltage

skmfkr
04-13-2008, 12:48 AM
i would try to find a diff cd player to swap it out with first. before u send it off to warranty replacement

CaptNKILL
04-13-2008, 03:46 AM
Dumb suggestion, but make sure you didn't accidentally disable your sub output. When I got my new Kenwood HU last year I wasn't used to the controls and my sub cut out for no reason while I was driving. I thought something was wrong but it turned out I'd just accidentally turned off the sub while fumbling with controls in between songs.

Paaco1981
04-13-2008, 04:45 AM
Dumb suggestion, but make sure you didn't accidentally disable your sub output. When I got my new Kenwood HU last year I wasn't used to the controls and my sub cut out for no reason while I was driving. I thought something was wrong but it turned out I'd just accidentally turned off the sub while fumbling with controls in between songs.

Thanks Capt, my sub level is all the way up, still no output. Thanks for the suggestion though. I'm actually thinking about warrantying my HU and just selling it. I called them today and they said ship it to them and they would send me a new one. If so I want a Pioneer Avic D3 unless someone has a better indash nav suggestion.