Hi,

I've just installed a Sony Cd head unit, and Sony 4-way amp driving two 7 x
10's on channels 1 and 2 and a sub which is bridged across 3 and 4.

The head just drives 2 100mm units in the dash

Systems sounds great on both CD and Radio but when I switch on the engine I
get a high pitched interference which varies in pitch according to revs,
regardless of the source (CD or Radio).

My question is what causes this interference and how can I kill it ?

TJ

First thing to try is to check the grounding and change the ground to
another point in the car for both amp and head unit, this should resolve the
problem but if it doesn't pick up a ground loop Isolater from maplins(costs
about £8) for the phono leads. I had exactly the same problem and the ground
loop isolater has got rid of the interference.

Ritz

"news.gxn.co.uk" wrote in message
...
Hi,

I've just installed a Sony Cd head unit, and Sony 4-way amp driving two 7
x
10's on channels 1 and 2 and a sub which is bridged across 3 and 4.

The head just drives 2 100mm units in the dash

Systems sounds great on both CD and Radio but when I switch on the engine
I
get a high pitched interference which varies in pitch according to revs,
regardless of the source (CD or Radio).

My question is what causes this interference and how can I kill it ?

TJ

"news.gxn.co.uk" wrote in message
...
Hi,

I've just installed a Sony Cd head unit, and Sony 4-way amp driving two 7
x
10's on channels 1 and 2 and a sub which is bridged across 3 and 4.

The head just drives 2 100mm units in the dash

Systems sounds great on both CD and Radio but when I switch on the engine
I
get a high pitched interference which varies in pitch according to revs,
regardless of the source (CD or Radio).

My question is what causes this interference and how can I kill it ?

TJ


If the RCA leads and the power lead run near each other, make them not. That
and the grounding suggestion are 95% likely to solve your probs

HTH

M

Thanks Guys,

I can confirm that the Amp is wired directly to the battery terminals while
the head unit is just wired into the main loom as normal in place of the old
head unit, is this incorrect ?

I've made a brief check through the system..

The RCA signal leads run from the rear of the head unit and are routed back
to the amp without passing any power leads on the way.

The amplified signal leads which run from the Amplifier to the rear L/R
speakers are routed through the vehicle and are not pinched at all but are
pressed quite tight in places would this have any bearing on the
interference ?

I hope to find time to run right through it again in more depth over the
weekend.

Cheers

TJ