Author Topic: Pre amp voltages  (Read 2399 times)

Offline JezGTI

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Pre amp voltages
« on: 12 March 2004, 00:45 »
Looking at CD/MP3 head units for my MK2.  I may well want to add a sub woofer at some point and an amp, what is the pre amp voltage I should be looking for (they seem to vary from unit to unit).  Don't want to spend much on the head unit (up to ?150), will that get me something half decent? Cheers Jez.

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Re:Pre amp voltages
« Reply #1 on: 12 March 2004, 10:33 »
pre amp volts is the volts that sits on the aux leads going from your headunit to your amp.

The higher the better i think ???

Offline Dizzie

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Re:Pre amp voltages
« Reply #2 on: 12 March 2004, 16:38 »
some pioneers are 6.5v! my kenwood is 5v
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Offline jasonpi

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Re:Pre amp voltages
« Reply #3 on: 13 March 2004, 20:28 »
dont know what u can get 4 a 100 quid but bluemk2 is right the higher the better just make sure u draw current from the battery aswell as the ignition barrel

Offline S11EPS

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Re:Pre amp voltages
« Reply #4 on: 13 March 2004, 20:40 »
Definitely the higher the better.

Like Dizzies, mine are 5 volt.

You can always by a line driver, which will boost the voltage of your pre-outs, but to be honest, if its just a sub you're powering the voltage (and therefore signal to noise ratio) isn't as key as it would be if you were amplifying front components.

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Offline Dizzie

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Re:Pre amp voltages
« Reply #5 on: 16 March 2004, 19:38 »
always use decent RCA leads and a phat power cable to ensure the best sound. IXOS do some good stuff. about ?40 for their 4 gauge amp wiring kit and about ?30 for a RCA lead.
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Offline paladin

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Re:Pre amp voltages
« Reply #6 on: 17 March 2004, 23:32 »
With preamp voltages, higher is better for signal-to-noise.  Think of it this way..

If you were sending 2 volts (old standard) to your amp (or sub) and you're getting a random noise (let's say from the fuel pump) thats about .5 volts (which is a lot, but I digress..), your amp of course is going to boost both up equally aka about 1/5 the signal will be noise (.5/(2.0+.5)), whereas if your preamp is 4 volts it would be 1/9th of the total signal(.5/(4.0+.5)) ...

Now, if you've wired it up so that the system won't catch any noise, then none of this matters.. and and you might want to start competeing, hee.
« Last Edit: 30 March 2004, 00:20 by paladin »
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