line driver

[twink 0]

im runnin out of preout voltage so i decided to buy a line driver, question is, does adding a line driver bypasses the gain of the amp? turning the gain all the way down wouldnt affect the line driver's settings?

[KU40 173]

what do you mean running out of preout voltage?

No a line driver does not bypass the gain. The amp doesn't know it's there, it just receives a higher voltage signal. You just match the amp gain with the input signal, just like if it were coming from the head unit. The amp doesn't know the difference.

[///M5 2,833]

im runnin out of preout voltage

Your amp has a gain knob, pre-out voltage shouldn't really matter

[JimJ 11]

Did it get scared and run away?

[Dr Durden 0]

Did it get scared and run away?

It's probably an Alpine, so it was never there to begin with.

[KU40 173]

Did it get scared and run away?

It's probably an Alpine, so it was never there to begin with.

Hey my alpine has 4v. I was actually thinking Pioneer, most of theirs have used 2v and I'm not even sure they do that.

[twink 0]

my headunit is pioneer with 2v preout. should I turn the line driver all the way up? and then match with the amp's gain knob?

[KU40 173]

Compare the line driver's output range to what is acceptable by the amp. If you tune your line driver to put out 12 volts but your amp only accepts up to 6 volts, well, you'll have a problem. Other than that, the voltage you choose for it to put out is pretty negligible as long as you match the amp's gain to it as you mentioned.

[helotaxi 46]

Nothing to be gained by using a line driver. Don't waste the money.

[twink 0]

i think i'll be needing one because i cant play at high gains. but when my gain is low, its not loud, where its driven at 200watts though. running at high gains makes a lot of noise.

[helotaxi 46]

What kind of noise?

[KU40 173]

Nothing to be gained by using a line driver. Don't waste the money.

i think i'll be needing one because i cant play at high gains. but when my gain is low, its not loud, where its driven at 200watts though. running at high gains makes a lot of noise.

I generally agree with Helotaxi's statement. However, I noticed that on one install I did with a Pioneer head unit I'd have to turn the gain quite high and would get quite a bit of noise, as it sounds like twink has. I redid all the grounds and did all the other tricks to try and get it to go away, but it wouldn't. When I got a cheap line driver (I think it increased the voltage from the head unit's 2v to about 2.5v, ha) and could lower the gain, the noise reduced. I don't know if it was the amp not wanting to have a high gain or something in the signal chain, but the higher voltage helped reduce the noise.

edit since I just saw Helotaxi's new post: My noise was just static.

Edited August 19, 2008 by KU40

[helotaxi 46]

edit since I just saw Helotaxi's new post: My noise was just static.

That is the one thing that a line driver will actually help with. But seriously, with the HU set correctly there should be more than enough voltage to keep you from excessively amplifying the thermal noise from the RCAs. With a good amp it doesn't become much of an issue anyway. You can pretty well max the gain and just barely hear a tiny bit of hiss on a zero data track.

[Dr Durden 0]

Nothing to be gained by using a line driver. Don't waste the money.

That's an ignorant statement if I've ever heard one.

NOTHING? Not true in the least bit.

Edited August 19, 2008 by FoxPro5

[Dr Durden 0]

Compare the line driver's output range to what is acceptable by the amp. If you tune your line driver to put out 12 volts but your amp only accepts up to 6 volts, well, you'll have a problem. Other than that, the voltage you choose for it to put out is pretty negligible as long as you match the amp's gain to it as you mentioned.

Not true. Not one HU on the market puts out their rated specs because they are MAX ratings. You need to listen to 0dB tone to get that number. Do you listen to sine waves?

Music is dynamic. Most of the chitty music nowdays is way too loud, but is still down 10 dB. The waveforum of the music your HU is playing drives the output voltage; it is not constant.

I've never ever heard of someone over-driving their amp with pre amp voltage. I would think the input impedance is too great anyway???

[KU40 173]

Compare the line driver's output range to what is acceptable by the amp. If you tune your line driver to put out 12 volts but your amp only accepts up to 6 volts, well, you'll have a problem. Other than that, the voltage you choose for it to put out is pretty negligible as long as you match the amp's gain to it as you mentioned.

Not true. Not one HU on the market puts out their rated specs because they are MAX ratings. You need to listen to 0dB tone to get that number. Do you listen to sine waves?

Music is dynamic. Most of the chitty music nowdays is way too loud, but is still down 10 dB. The waveforum of the music your HU is playing drives the output voltage; it is not constant.

I've never ever heard of someone over-driving their amp with pre amp voltage. I would think the input impedance is too great anyway???

Yeah I do listen to sine waves. Lots of different ones at once, in fact. They make music. You've probably never heard of an amp being overdriven because most head units put out 0-8 volts and most amps can accept that. But I bet I can get it to clip with a 12v signal.

You may have to define your MAX usage a little further. If it's like those amps that say 200 watts rms, 400 max, then that's incorrect. But if you mean maximum RMS value, then yeah. But most head units will put that out if you turn the volume high enough. At least I saw a test of an Eclipse head unit that put out 8 volts starting about 80% of maximum volume level. But I don't know how that plays into what I said? I wasn't concerned about whether it was rms or max, I just said if you put 12 volts.........

Edited August 19, 2008 by KU40

[twink 0]

What kind of noise?

Hiss sound at low volumes.

[twink 0]

Ive experienced this problem after swtiching to a new pioneer headunit. My old one has 6v preout non clipping, but had mechanical problems. So I bought a low mid level pioneer to save some cash.

[helotaxi 46]

Nothing to be gained by using a line driver. Don't waste the money.

That's an ignorant statement if I've ever heard one.

NOTHING? Not true in the least bit.

For 99% of people out there with a modern HU there is nothing to be gained by running a line driver. The HU puts out more than enough voltage to drive an amp to full power. As long as there's not noise at the gain setting required to get full power from the amp, the line driver does zip. The main reason that you get noise is a crappy preamp section in the amp.

Input impedance doesn't affect preamp voltage. Voltage and impedance are totally independent.

[Adrian_D 520]

Nothing to be gained by using a line driver. Don't waste the money.

That's an ignorant statement if I've ever heard one.

NOTHING? Not true in the least bit.

Details ?

I'm curious of the possible benefit

[benz280se 0]

well i put an audio control line driver in between my dvd player (crappy power accoustic) and the eq so it feeds a good signal into the eq and it made a world of difference. i turned the gains down on my amps to almost minimal and i get no distortion,feedback or hissing. for the people that said there is no benifit that blanket statement is a load of crap and really pisses me off because it all depends on your head unit and or eq and what your looking to do with them and the sound they put out. as far as a line driver making your amps run cooler...well i don't see mich of a difference in that. mainly because even though the amp is recieving a clearer louder signal it's still causing your amp to put out it's power. and if you are going to try a line driver use one that is worth the money or it will be no use. audiocontrol (imo the best), ppi, jlaudio, phoenix gold. youll pay a little more but it will be worth it if you do it right.

Edited August 20, 2008 by benz280se

[helotaxi 46]

Nothing to be gained by using a line driver. Don't waste the money.

That's an ignorant statement if I've ever heard one.

NOTHING? Not true in the least bit.

Details ?

I'm curious of the possible benefit

There's only one. It can mask the noise floor of a noisy preamp. It can't make the amp run cooler because the relative position of the gain dial has no bearing on that at all. It can't make the am produce more power if the preamp voltage of the HU is already enough to drive the amp to full output. The only purpose is hiding noise. If you have an outboard EQ, you really don't need one because every decent EQ that I know of has a line driver built in. The problem with adding one if you don't need it is that you run the risk of creating a ground loop and inducing more noise intot he system every time you add another component to the signal chain.

A basic understanding of how amp gains and the gain structure of a system work would tell you that a line driver isn't some kind of magic box and has no place in pretty much any system that uses quality components. If you want to disagree, explain what it actually does that is of tangible benefit to the system. Unless you are experiencing noise that decreases with gain setting, a lower gain is not inherently better. If lower gain was automatically better, they would be less sensitive in the first place.

[twink 0]

Switched my old Pioneer with 6v preout and heard a big difference. No noise and lower gain.

[///M5 2,833]

well i put an audio control line driver in between my dvd player (crappy power accoustic) and the eq so it feeds a good signal into the eq and it made a world of difference. i turned the gains down on my amps to almost minimal and i get no distortion,feedback or hissing. for the people that said there is no benifit that blanket statement is a load of crap and really pisses me off because it all depends on your head unit and or eq and what your looking to do with them and the sound they put out. as far as a line driver making your amps run cooler...well i don't see mich of a difference in that. mainly because even though the amp is recieving a clearer louder signal it's still causing your amp to put out it's power. and if you are going to try a line driver use one that is worth the money or it will be no use. audiocontrol (imo the best), ppi, jlaudio, phoenix gold. youll pay a little more but it will be worth it if you do it right.

"world of difference" in what way? You shouldn't have had any feedback or distortion without it, if you did it was operator error on the gain settings.

[twink 0]

if your amplifier has 6v input sensitivity (gain), are there chances of damaging it if i'll use a line driver with 8V