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View Full Version : How important is preamp voltage?



osmith
10-19-2010, 11:50 PM
I am in search of a head unit but I cannot seem to find one with everything I want lol. one of the closest ones seemed great, but the preamp voltage was lower. How important is that?

Sarthos
10-19-2010, 11:54 PM
It's not extremely important, it's dependent on the quality of the headunit. I'm pretty sure a 2 volt Alpine pre-out is still better than a 32 volt Boss pre-out. Higher voltage pre-outs can help with noise rejection. Which, in turn, can help prevent some subtleties from being lost.

osmith
10-19-2010, 11:57 PM
Ok, the alpine I was looking at had just about everything i wanted, but it was the one that had the 2v pre out...but it has still came closer to perfect than any others thats why i was curious

Sarthos
10-20-2010, 01:49 AM
Alpine might work, but I already see a problem with the Alpine unit...It's an Alpine :p

osmith
10-20-2010, 01:38 PM
Haha, so what would you suggest if not Alpine?

benzmansl65amg
10-20-2010, 01:40 PM
Kenwood excelon x794 for $200

osmith
10-20-2010, 01:50 PM
I guess I should have stated that Im looking for one which is a dvd player as well, haha. Also with a WVGA resolution.

hispls
10-20-2010, 02:03 PM
I guess I should have stated that Im looking for one which is a dvd player as well, haha. Also with a WVGA resolution.

AFAIK there is no DVD player that has >2V pre outs. Personally I use the last model Jensens since they have 5.1 surround.

Most amps perform fine off a 2V signal, if not buy a line driver/pre-amp (I used to run one for my sub amp...28$ PG from sonicelectronics...worked fine) and I have always had strong suspicions that the pre out voltage numbers aren't always terribly accurate on HUs anyway.

osmith
10-20-2010, 02:14 PM
A pioneer and Eclipse both have 5v preouts, and they are both dvd players

xoutofmyheadx
10-20-2010, 02:17 PM
nothing wrong with alpine. one of the best hu's made out there.

ricoshay
10-20-2010, 02:24 PM
some jvc double dins have higher voltage pre-outs...and detachable face

osmith
10-20-2010, 02:26 PM
Are the jvc's decent units?

xoutofmyheadx
10-20-2010, 02:36 PM
i use to run jvc alot long long ago. i liked em alot. eventually went back to alpine and could tell a difference. you shouldn't be dissapointed with a jvc. pretty good, and they are cheaper.

PowerBomb
10-20-2010, 04:01 PM
I'm currently running a JVC AVX-820. Picked it up last year because I wanted 4+ volt pre-outs, blue tooth, and title/artist/song displayed for Sirius. After some research, my only real option was a large screen (DVD player or Nav unit). Because I travel a lot and my car ends up at various airports and other unattended areas for days at a time, detachable face was a must.

Turns out that JVC was my only option at the time, and it turned out to be a pretty good one. No, it isn't a high end SQ deck, but it sure as heck is a fine "daily driver" deck. Pre-out voltage is good (5v I believe), the display looks good, and the fact that blue tooth and iPod control was built in vs. an external boxes made install much easier.

I'm pretty sure the 820 is gonna be hard to find, but the 830 is $475ish and well worth it.

Sarthos
10-20-2010, 05:36 PM
I'm about to drop in an Eclipse single DIN flip-out with 8v pre-outs.

And nothing's particularly wrong with Alpine, but with the ones I've seen and used, they pretty much all have the same features until you get their top of the line model. That and after getting used to my Eclipse, I couldn't stand my old Alpine when it went back in. But generally I'd say Pioneer is better than Alpine, so long as you don't blow the Pico fuse, Alpine is generally around the same as Kenwood or JVC, all of which are way better than Boss and the like, but a few brands like Eclipse just stand out above Alpine.

Your whole setup matters though when picking a headunit. I've found high voltage pre-outs to be more helpful to mids/highs than to subs. If you're running your mids/highs off the headunit's internal amplifier, I wouldn't worry about high volt pre-outs

VWBobby
10-20-2010, 07:43 PM
Preamp voltage is somewhat important if you're running long RCAs from the front to the back of your install. If you have 12-foot+ RCA's, I would like something more than 2V pre-outs to prevent too much voltage drop. The more you have to turn up the gain on your amps, the more chance of noise being introduced, hence the higher pre-out voltage. A line driver accomplishes the same thing, as mentioned in the post above.

Kenwood and Pioneer both have the best options I've found for less than $600 in DVD. After that point, you can get into some of the more higher quality units with more features.
JVC has a lot of bang for the buck, along with Kenwood but be sure to look for a unit with a good EQ if you need one. A lot of them only have preset EQ's with "rock", "rap", etc instead of a real EQ.

Wingman0121
10-20-2010, 08:31 PM
Wasn't there some older Rockford headunits that has over 10v of preamp output?

whitedragon551
10-20-2010, 08:33 PM
Didnt someone just make a topic about preout voltage?

It doesnt mean jack ****

http://www.caraudio.com/forums/wiring-electrical-installation-help/490485-my-pre-out-voltage-predicament-what%92s-your-$0-02-a.html


Wasn't there some older Rockford headunits that has over 10v of preamp output?

There is an Eclipse HU thats capable of 16v preouts.

Sarthos
10-20-2010, 09:08 PM
The problem with all of this is that the ONLY way to know for sure would be to have two headunits that are identical in every way including the pre-amp stage, but have different pre-amp outputs... because this is a contradiction, there's no real way to know for sure. It'll help a bit with noise rejection is the main thing, but unless you listen to music real quietly you won't notice such a small amount or rejection.

osmith
10-20-2010, 10:16 PM
Thanks a lot. All of this has been a big help. I was looking at Eclipse, but the screen resolution wasn't high enough on them for me. The alpine ina-w900 is the one im looking at and as far as i can tell the only thing it didnt have that i was interested in was the high voltage preouts. It even has an LED backlit screen which makes a huge difference, at least in tvs it does.

Sarthos
10-20-2010, 11:13 PM
If you want the BEST in SQ and resolution, you'd need to run two separate units, one for sound and one for video.

osmith
10-20-2010, 11:20 PM
Ok, if I ran two units what would your suggestions be? Would my video unit be A/V or would it be a strictly video unit?

Sarthos
10-21-2010, 04:18 PM
strictly video IF you did that. But it's just so much easier to run one decent unit.

osmith
10-21-2010, 04:54 PM
Haha, it's too late, you've already got my wheels turning on how to put a 15in screen in there.

Sarthos
10-21-2010, 04:57 PM
In that case you would use a 15" flip-down screen
An in-dash CD player/tuner for better SQ
and a separate in-dash DVD player to connect to the screen.
Use the CD player/tuner for music and such
Use an aux input to connect the DVD player to your CD player if you listen to movies

osmith
10-21-2010, 08:50 PM
What about fiberglassing the screen into the dash?