babber

A mate has just bought loads of Phoenix gold stuff second hand, and it comes with line drivers. What is the point of using them ? All I can see they'll do is force the amplifying to distort, or am I missing something here ?? Surely raising the input into an amplifier will just cause the amplifier to distort.

Phill

PS Amps are Phoenix Gold

m18use

They up the voltage from 4volts to 9 volts

babber

"They up the voltage from 4volts to 9 volts"

I always thought that RCA is 1 volt

Phill

m18use

features:
Isolated Mounting Clips
Variable Output Level Control
Peak Level LED Indicator
24kt Gold Plated Input And Output Connectors
Pulse Width Modulated Power Supply
Quick-Connect Power Connector
Phoenix Gold's PLD1 high voltage line driver makes the most of your car audio system by transmitting up to an 8 Volt signal from the source unit to the rear of the car. This method of transmitting the audio signal increases dynamic capability and decreases the possibility of noise radiating into signal cables.
This line driver boosts the signal up to 20dB, allowing the next component to operate with lower input sensitivity setting for a higher signal to noise ratio. The PLD1 also features a 30ohm output impedance that enables it to drive long signal cables to multiple components with ease. The PLD1 maximizes sound quality further with a peak indicator that simplifies proper gain adjustment.

Manufactured with high quality parts, the PLD1 features a G10 glass epoxy circuit board and audiophile grade 1% metal film resistors. Choose either the sleek high gloss white powdered coated finish or rough textured black.

chiark

Theoretically, it should lower your noise floor as you're amplifying a low level signal to a higher level prior to sending it through an electrically noisy environment - your car

If it's cheap enough, and your amps can take it, try it.

dr_ming

Chiark, you are right in that the line driver should make the signal more immune to the cabling picking up interference from the car's electrical system (provided it's output impedance is low enough). I guess this is its main selling point. However, the overall noise figure will be worsened slightly by the line driver, as it will amplify any incoming noise by the same amount as the signal, and will also add a little noise of its own. Similarly, it will add a little bit of distortion of its own too. IMHO, better not to bother, just be careful where you route the cables.

[Edited by dr_ming - 1/3/2004 9:52:00 PM]

BigRed

Give me optical anyday, if i could afford it that is.

dr_ming

Optical is not without its disadvantages either Long (>1 metre) optical cables can give rise to optical multi-paths in the cable (even in mono-fibre cables), which gives clock jitter, and hence distortion. IMHO, digital audio via a 75 ohm SP/DIF coax interface is your best bet. Provided that the cable IS 75 ohms, and it IS terminated correctly at both ends, there are no dissadvantages.