I've fitted a HiFi to my 348. Not rocket science, just a head unit, amplifier, crossovers, and speakers. I keep on getting a deafening screeching noise (interference) which the amp feeds out to the speakers and which seems to be coming from the +ve connection which is used to turn on the amplifier. I took this originally from the radio output used to power up electric aerials etc. and I got the noise about 9 in 10 times when switching on. When I took the feed direct from the ignition, the screeching noise only turns up very seldomly. It almost seems to be some other ignition powered device which is throwing out electromagnetic garbage which the amplifier is feeding on and amplifying. Every so often, it appears that the race to power-up first is won by the amp and not the polluting culprit (or vice versa) and everything is fine. When the ignition is on, all sorts of motors start whirring and whining (ABS? AirCon Temp Sensor fan? etc?). Has anyone experience of a "dirty" solenoid or motor or pump or fan or whatever which might be radiating this stuff, or maybe has another idea where the interference might be coming from? Thanks in advance for any experience you might have Drew
When I bought my 348 a year ago I think I opened the lid and turned the radio on to see if it worked. If I remember right it did. I turned it off and have not turned it on since. My radio may not get used again until I sell it and the new owner turns it on. Well maybe if there happens to be a Wisconsin Badgers game on that day it may get used again. Rodney 1990 348 TS
Drew, common issue with high power amp systems... especially in older cars. They make a large capacitor device that you put inline with your blue remote wire that turns your amp on. They also make ones for the primary wire. Stop into your local car-stereo shop, they can point you in the right direction, especially if you take the car there and let them hear the noises.
If I understand what you are describing. It's a whining noise that is probably RPM dependent, meaning the pitch of the whine goes with the revs of the motor. A ground loop isolator can lessen the noise if not eliminate it. Or if what you're talking about is the speakers pop on turn on/off then a relay can delay when the amp comes on to prevent that. Hopefully, one of those might help.
That sounds like a very good idea - I'm afraid the South of France isn't the best place for competent workshops, but there are a few HiFi megastores where I can look for the components. Off hand, I know they have Buck Rogers Spaceship capacitors but I think those are to smooth out the power to Boom-Boom speakers, no? A friend who does EMC stuff on aircraft (electromagnetic compatibility) said that "in the old days" electric pumps and motors weren't really very well shielded so I guess this is what you're saying in different words. I'd LOVE to find out the cause as it would be very elegant to just isolate the culprit, but your solution sounds like a good panacea! Do you think it would work if my remote wire is red/white and not blue? Cheers Drew
Neither of those! It's a white noise screech when the ignition is on and completely rpm independent. Interestingly, I know the noises you mean very well - I used to have a Blaupunkt in another car and the "POP" it made on switch-on cleaned the wax out of my ears every time. I am interested in this "ground loop" thing as a mate said I should "eliminate ground loops". I thought he was on a campaign to eradicate the game of crocquet but perhaps I was mistaken. Tell me more about ground loops please! Drew
Not THAT helpful, Rodney, but no doubt the forerunner of a plethora of postings saying that the music of a Tubi/Stebro/X-Ost/Fuchs etc., is ALL the music you need in a Ferrari! However, it's my birthday, so I'll be kind with you! As a cure, your idea reminds me of the old chestnut: A guy goes to the doc. He says " I have a sharp pain in my lower abdomen whenever I laugh". Doc says "Well stop laughing then". I've heard there are F-Car owners out there who don't drive an 11 hour/1100km journey in their car 4 times a year, who don't drive a 3500km/5 day round trip every two years, who don't sit at a ferry terminal waiting for boarding during two hours, who don't need the friendly voice of a navigation system when they go downtown Marseille in their F-Car. When I'm not doing those, I take the car out for an hour or so to burn up a few country roads. THEN, I have the window open and use two gears lower than required. THEN, I don't have the radio or nav on. It's just that my Ferrari usage isn't confined to those outings. Above all, I have the ideal character trait for 348 ownership.......... . . . . . . . . . . . . . . . . . . . . I love fixing things! BTW, I'd never heard of any games that badgers do. Is it like cock fighting or greyhound racing?
Have been fault isolating more and more this morning. I've now JUST wired up the amplifier and the speakers/crossovers. Amplifier is not connected in any way to the radio. I've taken direct battery plus for the amplifier - no switching signal or IGN plus Ignition is turned off. Radio is completely removed electrically speaking and is turned off anyway. I still get the noise. Speakers are wired up with crossovers (part of the kit, not a DIY job). Earth is absolutely perfect (0,7 ohms). Arrggghhhh! Guess I'll have to hardwire the battery positive to the amplifier. Other than that, maybe something to do with the crossovers? When I disconnect one speaker or channel after the other, the noise simply gets les and less as one speaker after the other is disconnected. So it doesn't seem to be noise which is getting in via the speaker cables running behind the dash or whatever.
The interference is in the electrical system, it doesnt matter what is or isnt connected. The inline capacitor simply ''eats'' the interference. It also doesnt matter what color the remote lead is, the universal color code for aftermarket car stereo wiring in the USA, its always blue... it could be anything in Europe! In the USA the red or red/white wire is the switched hot wire. You may also want to see if an inductive collar is on the constant and switched hot wires... some systems come with them, some dont. sometimes they come with them, but you have to put them on the wires. Take a look at your computer monitor cable, or some of your USB cables (like for a digital camera), you'll find a big round tater-tot clamped onto the wire... thats an inductive noise suppressor. That creates a magnetic field around the wire, and kills electrical interference... same prinicpal. If your system didnt come with any inductive suppressors, you can buy them at electonics stores or even computer stores. Try buying a large one and clamp it on the entire wiring harness coming out of your stereo. It also wouldnt hurt to buy a few small ones and put on on every power wire in your system. My last suggestion is.... I have seen in the past, instead of a capacitor, a device which looks like a thread spool wound with about 100 feet of 22 gauge solid copper wire (creating a coil) used to suppress noise. This method uses massive resistance on the power wires to basically ''wear out'' the noise before it reaches the head unit. I dont know what they call those things, but if you describe it to a car stereo guy, he should know what you're talking about. One or a combination of these methods will ulitmately resolve your problem... its gonna take some trial and error tho.
After hearing more detail on the problem, TheOnlyest seems to have a pretty good suggestion in using the coil. The ground loop isolator I was referring to gets rid of any whining noise usually caused from a insufficient ground or interference. I have seen noise also come from aftermarket ignition systems and are nearly impossible to get rid of. So basically I would check all grounds, and make sure all signal wiring is away from any power/ ground as interference can sometimes "jump" to the signal causing noise. Let us know how things come out if it gets resolved.
Well, I've been following some pretty drastic fault diagnosis procedures over the last day or so. To cut a long story short, I now have the amplifier, a loudspeaker, and a car battery on the workbench and NOTHING else. I have connected the battery (+) to the amplifier (+), the battery (-) to the amplifier (-). I have connected a wire via a switch from the battery (+) to the amplifier "power-on" terminal. I have connected one single loudspeaker to one of the loudspeaker outputs. None of the wires is near to another one. I switched on, I got the same noise. I have taken all of the covers off the amplifier and wiggled all joints and components. I have put finger pressure on all PCB's. I then found that, if I wiggled the power-on signal cable, I could get the noise to sometimes go away and sometimes come back. I disassembled the connector block, even putting Stabilant 22A on the pins where it plugs into the PCB. I got a really good connection to the power-on terminal and, hey presto - no noise. Being overjoyed about this, I tried to make sure the result was repeatable. I switched the amp on and off many times and, after about the 6th time, the noise came back. I waited for a few minutes, did the switch on again. No noise! So....... Q: what changes after you've switched on the amp several times one after the other? A: THE BATTERY VOLTAGE I hooked up a voltmeter and a trickle charger to the battery on the bench. The higher the voltage, the less chance I had of getting the noise. Once the voltage dips below about 11,5V the noise comes back at virtually every switch on. At about 11,7 volts, the noise sometimes gives a quick squeak and then shuts up. Above 11,9 volts, I can always switch on without the noise. If I switch on and off repeatedly, the battery doesn't get time to recover from the initial current drain and the voltage sinks and sinks until it reaches about 11,7 volts, then the noise starts re-appearing. Now I think I know what was happening in the car. The Ignition circuit and the radio circuit both have a 1 second (approx) delay before the relays click on - just like the amp. Sometimes, the amp just got there first and turned on using full fresh battery 12 volts before the ignition relay clicked and shock-dropped the battery voltage. In that case I got no noise. If the ignition circuit got there first, then by the time the amplifier relay clicked, it was already only getting 11,6 volts or so and I got the noise. This pattern of events seems to be completely independent of anything else which is going on in or around the amplifier. I even took out the entire PCB which regulates the sound circuits (crossovers, gains etc.) and the amplifier continued the same behaviour. SOMETHING in the input power side of the amp requires good clean powerful voltage otherwise (I guess) some relay or circuit starts struggling, radiates a spike or two which triggers a closed loop amplification and causes the white noise. At the moment, I see three possible solutions: a) junk the amp (bad, because it took a long time to find this very compact Blaupunkt amp and all the fixings are tailor made for it now) b) phone up Blaupunkt and hope they say "Oh yeah, we had a batch of them with chinese relays which stuck and needed full voltage to fly off. Send it in" c) Question: can I rig up some sort of inline capacitor which buffers the voltage and ensures I get full volts during the critical power on moment? Related question: When I measure the voltage at an unregulated point in my new Audi, I get about 13,8 volts. If I measure a brand new, charged battery, I get about 14 volts. If I measure pure unregulated Ferrari voltage on a new Bosch Silver and freshly charged battery with cleaned terminals including conducting terminal grease, I virtually NEVER get more than 12,2 volts. There seems therefore to be a horrendous drop from the battery to the first users. (Incidentally, my battery is in front wheel well, being a Euro GTS). I presume this is the effect of battery cable oxidation over the years to a point where the thick battery cable is sucking amps itself. This would mean my amp problem probably would never occur if I fitted it to the new Audi, but is exacerbated by the poor Ferrari state of things.
personally, I'm an immediate gratification kind of guy, so I'd find a new amp and see if that works. Make sure you have a good return policy in case the same problem arises. I'm sure you could find something of similar that would only mean a little rework to fit. If you can't find one locally, you could look at crutchfield.com, I'd guess they would fedex an amp to France and take a return if needed
I'm schizophrenic - I get torn between throwing the rubbish in the bin and a gut determination to solve the problem! To be honest, I sometimes go down the route of not even trying to get a refund because I just don't want to deal with the store/item/company again! I've reconfirmed now that, as long as I don't switch on everything at the first turn of the key when the voltage has taken a hit, everything starts up ok. It's still not good enough though, so I tried to ring Blaupunkt. They are, of course, on holiday. Anyway, I'll go down that route first as I'm dying to find out what this problemreally is and if it's known. Fitting a different amp will still remain a possibility. To be honest though, I didn't find another amp as compact as this one. It's a Blaupunkt TSA-460 4-channel and it's very small with very low heat development. I made up a special mount for it in the trunk (see thread "My 348GTS refresh" and I quite frankly don't want to that for another amp (although I could use my mounting plate to mount another mounting plate for a different amp, I guess. Let's see what Blaupunkt say! I must say the low voltage in the 348 is becoming a PITA. If you pull in to a layby, wind the windows up and down a couple of times, listen to the radio for an hour, then there's not enough voltage left and all sorts of weird things start happening.
Hi, maybe a ferrite core attached to the 12 V supplyline solves the problem, like this one: http://www1.conrad.de/scripts/wgate/zcop_b2c/?~template=pcat_area&zhmmh_area_kz=13&navi=breadcrumb&cachedetail=&p_load_area=1021027&p_artikelbilder_mode=Ein&p_sortopt=object_description&page=1&p_catalog_max_results=20 Regards, Georg
Drew, as your testing has determined you have an issue with a faulty amplifier. Most higher end audio amps can work with rail voltage between 10 and 17 volts (although peak watts will decrease with rail voltage obviously) and employ protection circuitry if the voltage is beyond spec. Rather than a band-aid solution get the amp replaced. A faulty amp can catch on fire.
Just got off the 'phone to Blaupunkt Technical Hotline. They say that the type of interference and sypmtoms I am experiencing are certainly consistent with a low rail voltage. However, they should only occur if the rail voltage dips below about 10V and CERTAINLY not at about 11,5V. They said this type of defect is not unknown and I should send the amp in and they'll exchange it. We got there in the end together, brothers!
