Kevin Bacon 5 Posted July 20, 2004 Any of you guys use a Ground Loop isolator? I'm picking up some interference from the Alternator (I think) and I really can't be arsed to pull the wiring out again, so would an isolator get rid of it? Cheers K Quote Share this post Link to post Share on other sites
Henny 0 Posted July 20, 2004 interested in this myself as I've just started to get some noise myself and it's very irritating to me.... (most people can't hear it :roll: ) Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted July 20, 2004 Yep it's annoying for sure! I've done several installs in VWs and never had a noise issue, until now. Why is nothing ever simple on bloody Corrados? I think Halfords sell these isolators (it's just a big inductance loop) so might try one this eve. Quote Share this post Link to post Share on other sites
andycowuk 0 Posted July 20, 2004 have you checked the noise supressor in the altenator is ok? Quote Share this post Link to post Share on other sites
G60Jet 1 Posted July 20, 2004 have you checked the noise supressor in the altenator is ok? I had bad noise on my stereo till i changed the brushes on my alternator, now im 99% sure the noise supressor is the other little wired on thing on the alternator. Change them both, the brushes only cost a around 5 quid iirc. If you are running an amp you should have it earthed back to the battery via a low impeadance wire, if not try running the earth back to the battery, not the chassis earth point in the boot. Quote Share this post Link to post Share on other sites
randal 0 Posted July 20, 2004 Also have the same problem, the cursed accelerator whine! Will try running a wire from the amp to battery at lunch, see if that solves it. Have heard mixed reviews on the isolators, one way to find out! ta randal Quote Share this post Link to post Share on other sites
andycowuk 0 Posted July 20, 2004 Also have the same problem, the cursed accelerator whine! Will try running a wire from the amp to battery at lunch, see if that solves it. Have heard mixed reviews on the isolators, one way to find out! ta randal On papaer, that wont fix it. Ground loop is a fixed hum that is a result of two different grounds, in the same system being at different potentials. The changing hum, reletive to engine speed, is a result of an AC componented frequency, sitting on the 13v DC level. You need to block the AC components, which is what the induction loop does. The altenator has an induction looop built in, but these can degrade with time. As G60Jet rightly says, it is about £5 for brushes, and same again for the noise supressor. That said, u know what its like with raddos.......the wire will probably fix it! lol Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted July 20, 2004 This is all good info, keep it coming ! Thinking about it, I think my noise is more a clicking than a whine, it's sort of engine speed related but doesn't really change pitch too much. I don't get any pops and clicks when putting the wipers on etc, so I'm wondering if it's ignition noise I'm picking up? If it is then the induction loop won't remove it as it's digital pulsing on the VR, not a cyclic AC output like an alternator...... arse..... I might still try the induction loop though as they're only a tenner. You're right about the amp's earth going to the battery, it makes no difference but earthing at a shared cluster of earths (star earth?) sometimes helps. Quote Share this post Link to post Share on other sites
G60Jet 1 Posted July 20, 2004 andycowuk, on paper your dead right, apart from one thing, a car only has one ground, earthing the amp directly to the battery will isolate any electrical noise from other equipment. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted July 20, 2004 And there is one more thing, there isn't enough room on my battery terminal for another large connector! To put you more in the picture, the amp is bolted to the back seat and is earthed to one of the seat back's retaining nuts. All the cables run down the passenger side of the car. I've done this numerous times in MK2s and MK1s etc with no noise. And the Corrado would have to go and change all that! What probably hasn't helped my cause though is bunching up the excess RCA lead into a bunch and tie wrapped it behind the dash! Although I've done that before too with no adverse effects........ Quote Share this post Link to post Share on other sites
G60Jet 1 Posted July 20, 2004 And there is one more thing, there isn't enough room on my battery terminal for another large connector! What probably hasn't helped my cause though is bunching up the excess RCA lead into a bunch and tie wrapped it behind the dash! Although I've done that before too with no adverse effects........ Kev Iáve got an RCA that a meter or two longer than it need it in my c so all the excess is floating around in the rear bench. Having the amp earth to the seat bolts is not the best of ideas considering there is an earth point behind the rear quater trim card where the window controller is and there is another in the boot for the lights (i wouldn´t use the light earth point though, you MAY get a click click every time you use your indicator Quote Share this post Link to post Share on other sites
andycowuk 0 Posted July 20, 2004 andycowuk, on paper your dead right, apart from one thing, a car only has one ground, earthing the amp directly to the battery will isolate any electrical noise from other equipment. No, it wont if the noise is on the power supply, and not on the earth - ie coming from the altenator. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted July 20, 2004 Nige, that was the nearest earth point to the amp and is solid. I'll figure it all out tonight and solve it. And whilst on the subject of ICE. What's a non-fading fader thingy? Now that the Pioneer is running the amp, a few more options have appeared in the menu system. One of them is NonFading on/off. When it's off, it produces a really bizarre sound. It's sounds lovely, almost live but at reduced volume on zero balance. If I balance over to the left or right, sound still comes out of the faded out speaker! When nonFading is set to on, the L & R orientation is reversed but the sound is louder. I don't get it. The orientation on the RCAs and speakers is most definitely correct. Confused...... :( Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted July 20, 2004 OK, picked up a couple of isolators from Halfords (Autoleads) and there's no instructions with them. Do they go at the head unit end or the amp end?? Cheers Quote Share this post Link to post Share on other sites
G60Jet 1 Posted July 20, 2004 Kev the seat bolt will earth but not that well, especially if its painted or grease as some of them are on mine Quote Share this post Link to post Share on other sites
randal 0 Posted July 20, 2004 OK, picked up a couple of isolators from Halfords (Autoleads) and there's no instructions with them. Do they go at the head unit end or the amp end?? Cheers Kev, how much did they set you back? Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted July 20, 2004 Nige, where's the best place to earth at the back? There's something rattling behind the rear card actually, so is in there a good place to earth? Randal, they're were £15 each mate. I needed two unfortunately as it's a 4 channel amp :cry: Quote Share this post Link to post Share on other sites
Guest Posted July 20, 2004 Kev, I've used them before with alternator whine and it didn't fix it. In the end I rewired it all (better cable, earths etc) and that fixed it (without fitting the isolators) gl though mate, its a very annoying noise when you have it, especially as Henny says, when you seem to be the only one that can hear it. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted July 20, 2004 Hmmm, shame you didn't post that earlier before I bought the darn things! Nevermind! I've used expensive RCA leads and all the connections are soldered, so maybe it's the earth point I chose? Unlike Henny's noise, mine is very loud and you'd have to be deaf not to hear it! It's a constant volume too, doesn't get any louder and is engine speed related, so gotta be the alty. Although it doesn't whine as such, but ticks.... Quote Share this post Link to post Share on other sites
randal 0 Posted July 20, 2004 Nige, where's the best place to earth at the back? There's something rattling behind the rear card actually, so is in there a good place to earth? Randal, they're were £15 each mate. I needed two unfortunately as it's a 4 channel amp :cry: Bummer me too! Although from what peeps are saying that's probably not going to help. Looks like it's a strip out, and run down the centre tunnel job for the cables. Wooop. :mad: Ta! randal Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted July 20, 2004 Looks like it's a strip out, and run down the centre tunnel job for the cables. Wooop. :mad: I think the same fate awaits me, too :x I can guarantee if you just draped the cables on the floor loosely to test it, it would be silent. As soon as you shove em under the carpet and put all the trims back on, the Alternator noise kicks in! Typical 'Corrado' factor! In a MK2 you could earth the amps to an Apple and wrap the RCAs around the alternator and it would still be silent..... Quote Share this post Link to post Share on other sites
Scruffythefirst 0 Posted July 20, 2004 What probably hasn't helped my cause though is bunching up the excess RCA lead into a bunch and tie wrapped it behind the dash! Although I've done that before too with no adverse effects........ You might be picking up noise from the bunch of cables under the dash - try coiling them in a figure of 8. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted July 20, 2004 Good point. They're bunched up next to a load of relays above the heater fan. I'll try moving them to down the transmission tunnel this evening and bunch the slack up at the rear of the car instead. Or better still, cut the excess slack away and reterminate the phonos. All fun and games eh? I hate doing the same job more than once......grrrrr! K Quote Share this post Link to post Share on other sites
RadoAds 0 Posted July 20, 2004 The RCA cables will be too close to a power source just experiment with there placement and your sure to cure it without messing with ground loop isolators and suppressors and such, make sure the RCAs arent running alongside the power cables for the amp is a good start :lol: and the figure of 8 someone mentioned earlier also helps some. Quote Share this post Link to post Share on other sites
randal 0 Posted July 20, 2004 Typical 'Corrado' factor! In a MK2 you could earth the amps to an Apple and wrap the RCAs around the alternator and it would still be silent..... LMAO, sod's law on that one. I may be in a different boat to you though, as I managed to carry the whine over from a previous install using the same amp. Maybe a fault actually within it....? Anyone want to donate me an amp for.. err.. "testing"? :lol: Quote Share this post Link to post Share on other sites
