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        General >> Problems >> Amplifier Problem
        
(Message started by: Paulus on May 5^th, 2006, 7:22am)

Title: Amplifier Problem
Post by Paulus on May 5^th, 2006, 7:22am

I have installed an aftermarket Amp, but I can't get it to work properly.

It is wired correctly and the light comes on to say that it is powering up.

It is a 4 channel amp, but I have any wired in 2 channels at the moment. My question is, do all 4 channels need to be connected and installed for the amp to work?

Can anyone help?

Paul.

Title: Re: Amplifier Problem
Post by Kjetil S on May 5^th, 2006, 10:48am

No, that shouldn't be necessary.

Try connecting a portable player to it and see if it will work then. (Probably obvious, but remember to start off with the lowest volume setting and increase carefully ;))

Btw, have you tried adjusting the input gain on the amp? That may be set to a very low setting.

Title: Re: Amplifier Problem
Post by Paulus on May 5^th, 2006, 11:16am

I have got all settings at about half way. I will try a different input and speakers over the weekend.

Title: Re: Amplifier Problem
Post by scorpio_man on May 5^th, 2006, 11:40am

hi there

this might help....
http://www.fordscorpio.co.uk/hifi_amp.htm

Title: Re: Amplifier Problem
Post by Paulus on May 7^th, 2006, 5:01pm

Here's an update.

I have connected all speakers and I have a problem.

When I switch it on, all I get is a popping sound that is deflecting the speaker cones to their full extent. The popping sound has a "train track" type of rythm.

I have tried a connecting up a different input, and I have tried a completely differnt set of speakers - same result every time. I do get a small amount of sound out that is supposed to be there, but the rest is the popping.
The popping sound isn't loud, it's as if the speaker cones are in slow motion going from one extremity of their range, to the other.

Why is it doing this?

Paul.

Title: Re: Amplifier Problem
Post by Kjetil S on May 7^th, 2006, 8:05pm

on 05/07/06 at 17:01:03, Paulus wrote:

Why is it doing this?

Always trust a fellow Scorpio owner to come up with good questions ;)

Sounds VERY weird.

What voltage is the amplifier getting from the battery (measured on the amplifier input)? Should be 13+V

Shorted speaker terminals?

Blown amplifier?

Title: Re: Amplifier Problem
Post by Paulus on May 7^th, 2006, 9:04pm

Dunno what it is getting. I haven't checked. I will check it out.

It sounds to me like a dodgy amp. :'(

Title: Re: Amplifier Problem
Post by Matt on May 7^th, 2006, 9:09pm

hi all

how have you run the cables

cables from the head unit (cd player) and from the amp to the speakers should not be run along side power cables (including the power cables to the amp) although the small REM wire doesnt matter

it sounds like you have an interferance problem, the poping may be electrical pick up from the cars electrical system

Title: Re: Amplifier Problem
Post by cossie_al on May 7^th, 2006, 10:17pm

this is probably obvious but do both +ve and -ve of all speakers run back to the amp? i.e. the negative of your speakers should not be earthed to the vehicle chasis

Title: Re: Amplifier Problem
Post by Paulus on May 8^th, 2006, 12:52pm

I have worked with electronics in the past and I have never heard interferance like this, so I don't think that is the problem.

All power feeds go along the LHS of the car from the front, all signal leads run along the RHS of the car.

I wish that you could see what I am experiencing. It sounds like a Scooby Doo sound effect. Regardless of what settings the amp or the head unit is on, I get the same result as soon as I power up the head unit. the volume/gain has no effect on the output.

Does that make things any clearer?

Paul.

Title: Re: Amplifier Problem
Post by Matt on May 8^th, 2006, 7:52pm

do you have the problem with the engine off or on or both?

ive heard of some cars (mainly fiats for some reason???) where the stereo pick up frequencies from the engine and a suppressor type unit has to be fitted

i think halfords sell a unit to stop it, cant remember what it's called tho :(

Title: Re: Amplifier Problem
Post by JohnJ on May 8^th, 2006, 8:35pm

Make sure you have low inputs for the amp as the standard ford stereo only has high outputs and even if the volume is low can cause the amp to protect its self and not work, try a portable CD player on it and if that works try a reducer or low input matcher, I think halfords have them.

Title: Re: Amplifier Problem
Post by Paulus on May 9^th, 2006, 10:22am

I have tried the audio output from a portable DVD player - same result.
I have tried both high and low level inputs to the amp (I have got a Sony stereo) - same result.
I have tried it with the engine running and stopped - same result.

HELP!!! ???

Title: Re: Amplifier Problem
Post by Kjetil S on May 9^th, 2006, 10:46am

Tried with another (known working) amp?

Almost sounds like it must be a fubar amplifier.

Title: Re: Amplifier Problem
Post by Paulus on May 9^th, 2006, 7:07pm

Nope. Don't know anyone with one to try (I have very few friends :'() It's brand new, so I haven't actually had it working :-[

Title: Re: Amplifier Problem
Post by Matt on May 9^th, 2006, 8:16pm

where about are you paulus? i have a sony amp in my old car still (it's only a 2 channel but should proove if your amp is a duffer)

im in bham

Title: Re: Amplifier Problem
Post by Paulus on May 10^th, 2006, 7:37am

I am working in Guildford during the week, but I live between Stafford and Telford, about 10 miles north of Wolves. I doubt that I will be able to do anything this weekend as I am helping out with a small music festival in the village where I live. The following weekend I have nothing planned.

Title: Re: Amplifier Problem
Post by JohnJ on May 10^th, 2006, 6:47pm

Sounds lile you have done most of what can be done to proove if an amp is working or not, if its new send it back and get another.

Title: Re: Amplifier Problem
Post by sector-9 on May 10^th, 2006, 8:22pm

There's only so many components in the system and you've ruled out the inputs and outputs by substitution. All that remains are the two things which have stayed constant during the tests; namely the power supply to the amp (is it getting enough current to operate?) and the amp itself.

Personally I would take the amp out of the car and try powering it directly from the battery (with an inline fuse of course) using good thick wires. A length of old 13A mains cable will suffice for this purpose. If, using known working speakers and a line-level input such as aux. out on a tape deck, and with thick cables supplying the power, it can only be the amp itself.

However before you take it back, check that it isn't set into 'bridging' mode or similar. Presumably you have the instructions that came with it so double-check just to see if there's any configuring that needs to be done on initial install.

In all probability though, it likely is broken... :(

Darren