My 1st car amplifier!..engine whine problem.

[deepanger]

Originally posted by Matttcattt
would connecting the CD player ground to the car battery ground help?

am using batteries for powering the discman as i dont like to find myself struggling into many directions for this headache prob.

about using a big filter capacitor before the power input of the
amp. , whats that big values mentioned in here? 10,000uF is enough?

[Diode]

The star grounding technique is probably the best mentioned but yes, the 10,000uF caps are the "big" ones I was mentioning!!!

Let us know what worked for you.... Gorund loops are always a pain in the *** and others will benifit from your knowledge!

Good luck,

Chris

[deepanger]

heey guys! ive a good news ...
when i putted a one 10,000uF 50V. cap. across the power input
of the amplifier, the whine noise has been reduced to about 50%
whats really great as a beggining!!, so what now?!
should i increase the capacitance and expect a more satisfying
reduction in the noise?! , or ineed more elements to build a good
noise filter!?

thanks again..
waiting for ur valuable replys!

[Diode]

I don't know if Egypt is on metric or not but get a 10mm steel bolt and wind about 50 turns on it and put it inline with the posative pole then the cap across as you have it.... I'll bet you get even less whine then!!!!! Put more turns as necessary and I'll bet it all goes away!!!! Try it out and let us know.

Chris

[Mach_Y]

You are just applying a bandaid to your problem with the capacitors / filter section you are thinking of adding. The normal fix of alternator whine is caused by a difference in ground potential between the source and the amplifier. In your case, your HU has a floating ground since you are running it off batteries, and therefore it has a different ground entirely from your amplifier. You can run a ground wire from your source (portable CD player) to the ground of your amp. Or you can buy a ground loop eliminator (which does the same thing as the previous method, it just connects the grounds through the shielding of the RCA's). Either way, the capacitor you installed is only a bandaid covering the underlying problem, but doing nothing to fix it.

[deepanger]

thanks God, it has been solved in two way:

1- itried to power the discman from a universal cigarette light
9V. adapter (diy one) ,and yes the whine sound has totally gone!
,about the reason , its simply caz of connecting all grounds of the
whole system (discman,amp....etc) to the same point... its the
same thing as (Mach_Y) mentioned before! thanks man...

2- ive built this simple diagram consisting of 2x 10,000uF caps.
and one inductor (50turns of thin insulated wire around a steel
bolt) and its also eleminated the noise completelY, as u mentiond
before (Doide)..thanks so much,, but the most imp. part is why?
this circuit IMHO works to purify the pulsating DC (due to noise)
to make the output more linear DC, am i right?? or i mess something?...

anyway, am really thankful for ur help all!!

[Diode]

YOWZA!!!!!

Great work! I'm glad to hear it because I have had many problems in the past also. No one ever told me to star ground everything! I just had to bruit force it with heavy noise filters. As the filter goes, you are simply smoothing the ripple like after an AC bridge rectifier, just at a different frequency, that's all.

Anyway, Thanks for telling us about your success and what you did....

You are welcome!

Chris

[Matttcattt]

Originally posted by Mach_Y
You can run a ground wire from your source (portable CD player) to the ground of your amp

i suggested this

[CarMan]

There is no need to star ground things in a car. If all the grounds are connected to the chassis, the chassis provides a much better bus (like a .01 gauge cable) than a long cable of 4 guage running to a common ground. You just need to make sure everything is grounded to the chassis.
I've heard plenty of engine whine, none of which couldn't be eliminated with good grounding and separated power/signal cables.
I currently have my power/signal cables running next to each other because of installation ease, but the signal cables are triple shielded and have a ground wire with them, which I connected to the deck and one of the screws into the chassis from my amp. I couldn't hear any engine noise without the ground but it didn't hurt to use it in my case.
To test for engine noise, even the slightest, get a BLANK recording, turn volume all the way up, and drive around. Rev the engine to fairly high rpm. Even a small amount can be very annoying.

[navin]

I need some help. the car is a OPEL Corsa Sail. A 1.6 liter hatchback.

http://www.automandi.com/Content/new...rsa%20Sail.asp

http://www.reachouthyderabad.com/bus...iznews/gm2.htm

My stereo consists of the following.

1 x blaupunkt car stereo (tape)
2 x blaupunkt 4 channel power amps (8 channels total)
2 pairs of Vifa 2way (front door and rear deck)
1 pairs of Blaupunkt Velocity coax (rear pods)
1 pair of Vifa 6" woofer (rear deck)


the first power amp feeds the front speakers and the rear speakers (Vifa 2 way). the second power amp feeds 2 Vifa 6" woofers and 2 4" Blaupunkt Velocity full ranges that are also in the rear. both the amps are mounted on the rear of the rear seat.

The amps and the head unit are grounded to the chassis albeit the head unit is the front and the amp in the rear.

the power wires run on the drivers side of the car and the RCA wires from the headunit run from the passenger side of the car.

I get very pronounced alternator whine. If I use the tapedeck without the power amps (using only 2 pairs of speakers) the whine is gone. that is if i use the speaker outs on the tapedeck direct to the speakers (no amps) the whine is gone. if i use the rca out and if i connect even one amp (any one amp) and only connect 1 pair of speakers the whine is back.

I am using reasonably high quality RCA wire.

any solutions.