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#10647 - 04/07/2000 12:07 Nasty Feedback Noise MK2
ClemsonJeep
enthusiast

Registered: 09/11/1999
Posts: 398
Loc: Ashburn, VA
Hey guys,

This might be an install problem, but I just finished getting the empeg hooked up in my Jeep.. When I turn the Jeep on, it makes a NASTY "electronic" noise.. as in, I can hear when the hard drive is reading, there is a humming noise, and so on. I haven't checked for alternator whine yet, but I would assume that it would also be there (as I never got that worked out from my Mk1)

Any suggestions as to what might be causing this? Or a solution on how to remedy it? :)

Thanks

(O|||||O)

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#10648 - 04/07/2000 16:04 Re: Nasty Feedback Noise MK2 [Re: ClemsonJeep]
rob
carpal tunnel

Registered: 21/05/1999
Posts: 5335
Loc: Cambridge UK
Did you remove your grounding cables?



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#10649 - 04/07/2000 21:25 Re: Nasty Feedback Noise MK2 [Re: rob]
ClemsonJeep
enthusiast

Registered: 09/11/1999
Posts: 398
Loc: Ashburn, VA
I sold them three weeks ago with my Mk1...so...yes :)

(O|||||O)

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#10650 - 05/07/2000 03:24 Re: Nasty Feedback Noise MK2 [Re: ClemsonJeep]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
Hmm, our mk2 installs (A-Class and yesterday my Beetle) are *completely* silent. Is the noise on both channels? Do the front/rear outs sound ok if you use the player at home?

Hugo



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#10651 - 05/07/2000 03:35 Re: Nasty Feedback Noise MK2 [Re: altman]
steve
stranger

Registered: 08/06/1999
Posts: 48
Loc: Cambridge, UK
Is the installer on your estate still doing Empeg installs? I need someone good to fit the Mk II in the kit, rather than the current hacky solution...




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#10652 - 05/07/2000 04:40 Re: Nasty Feedback Noise MK2 [Re: steve]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
They're not on our estate, they're just down newmarket road (part of the discount autoparts store near the roundabout) and yes, they're doing lots of installs :)

The beetle install (especially the very flat Phase Linear 10" sub) is a work of art :)

Hugo


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#10653 - 05/07/2000 05:14 Re: Nasty Feedback Noise MK2 [Re: altman]
teemcbee
addict

Registered: 04/02/2000
Posts: 687
Any web-sites of them?

TeeMcBee

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TeeMcBee
[orange]Mk2, # 080000143, 40+30 GB, Tuner, Peugeot stalk hookup</font color=orange>

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#10654 - 05/07/2000 05:37 Re: Nasty Feedback Noise MK2 [Re: teemcbee]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
Of the company? www.cambscaraudio.co.uk

No pics of my beetle yet, though Dominic did take some photos. When it stops raining then I might take some digital camera pics (don't hold your breath ;) )

Hugo



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#10655 - 05/07/2000 05:51 Re: Nasty Feedback Noise MK2 [Re: altman]
teemcbee
addict

Registered: 04/02/2000
Posts: 687
aaaahhh! THIS is the Cambscar... Now I know. Thx!

Of couse pics of any install are welcome, too. (I plan to take some during install when I finally get the Mk2.)

TeeMcBee

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TeeMcBee
[orange]Mk2, # 080000143, 40+30 GB, Tuner, Peugeot stalk hookup</font color=orange>

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#10656 - 05/07/2000 06:36 Re: Nasty Feedback Noise MK2 [Re: altman]
ClemsonJeep
enthusiast

Registered: 09/11/1999
Posts: 398
Loc: Ashburn, VA
Hmm, our mk2 installs (A-Class and yesterday my Beetle) are *completely* silent. Is the noise on both channels? Do the front/rear outs sound ok if you use the player at home?

I can hear it out of both channels. It sounds crystal clear at home from the leads on the back.

I'm wondering if I have some kind of grounding loop or whatever you guys were talking about at one point? It might not be the fault of the empeg... That's why I was asking for more information on what causes alternator whine, and so on.

What are some do's and don't when grounding AMPs? (I have two).

THanks,

(O|||||O)

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#10657 - 05/07/2000 06:53 Re: Nasty Feedback Noise MK2 [Re: ClemsonJeep]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31565
Loc: Seattle, WA
First, let's clear something up. Was the same wiring and amps used in this MK2 installation as were used in your previous MK1 installation? What's changed between the two installs?

Another thing to check. Try wiggling the unit in the docking cage and see if the noise changes. My MK1 recently developed a similar noise that goes away as I wiggle it in the docking cage. There's something wrong with docking connector (dirty perhaps) and it's causing grounding problems. I need to look into it.

Triple check all your wiring, and test the unit while the docking sleeve is de-installed from the vehicle (i.e., the wiring is still connected to the car but the docking sleeve is sitting in your lap). Narrow it down by elimination.

___________
Tony Fabris
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Tony Fabris

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#10658 - 05/07/2000 07:34 Re: Nasty Feedback Noise MK2 [Re: tfabris]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
Another thing to check. Try wiggling the unit in the docking cage and see if the noise changes. My MK1 recently developed a similar noise that goes away as I wiggle it in the docking cage. There's something wrong with docking connector (dirty perhaps) and it's causing grounding problems. I need to look into it.

I have had exactly this problem for about the last three months. I have to jiggle the unit very precisely into the sleeve to stop noise pickup and crackling noises that sound as if the differential outputs have no reference ground. Since I also have a two-amp installation, I thought this might have resulted from me only having fitted one of the reference straps. This weekend I fitted the second in the hope that if the connector was breaking contact on the single pin of the connector used for output stage reference, then a second reference earth would minimise this effect. Unfortunately, it has made no difference.

Having looked at the male and female sides of the connector, it appears as if the contacts of the female are compressing unevenly, and remain in their compressed position. This means that not all of the contacts are making proper contact in the connector, with odd results. Not resolved as yet. It does seems to be an audio, rather than feed current grounding problem caused by dodgy contacts - the empeg computer component continues to run regardless of output crackles. Since more than one incidence of this effect has been noted, it should really be reported as a bug relating to possible warranty issues. My warranty expires pretty soon

CJ - firstly, have you DC grounded (not earthed) both amps and the empeg at the same point? Have you checked that relative to the battery contact this point is at 0V? When you power everything on, is it still 0V? What grade of wire have you used to power/ground your amps and the empeg (it should be able to deal with at least twice the maximum current pulled by the device at full power)? Have you used the power filter in line with the empeg power line *only* (it cannot support filtering for all three as the core will saturate making it useless)? Have you checked (with engine off) the positive feed voltage at both amps and empeg? With the engine running, what are the same voltages?



One of the few remaining Mk1 owners... #00015
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#10659 - 05/07/2000 12:55 Re: Nasty Feedback Noise MK2 [Re: schofiel]
ClemsonJeep
enthusiast

Registered: 09/11/1999
Posts: 398
Loc: Ashburn, VA
I do have them all grounded to the same point. However, I'm not sure what the voltage is at this point, and I don't have the tools I would need to find this out either. (Need to go buy a voltmeter I guess).

I have seperate filters on all power lines. Well, seperate form my Amps/Empeg. The amps are pulled directly from the battery, whereas the empeg is tied into my wiring harness, and I'm not sure how many places it goes before it hits the battery. Could this cause a problem?

(O|||||O)

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#10660 - 05/07/2000 14:01 Re: Nasty Feedback Noise MK2 [Re: ClemsonJeep]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31565
Loc: Seattle, WA
The amps are pulled directly from the battery, whereas the empeg is tied into my wiring harness, and I'm not sure how many places it goes before it hits the battery. Could this cause a problem?

Not if it wasn't a problem with the Mk1. The only place this might be an issue is if you're grounding through the Empeg chassis only (i.e., the ground wire on the connector isn't going to a solid ground).

Try a "divide and conquer" approach to narrowing down the problem. Pull the sleeve out of the dash and disconnect all the audio plugs. Try plugging something else into the amps (such as a walkman's line-out) to see if the problem is the amps or the Empeg. If it's the Empeg, try connecting one RCA jack at a time (with the sleeve still out of the dash) and see if it's a specific connection. That sort of thing.

___________
Tony Fabris
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#10661 - 08/07/2000 15:54 Re: Nasty Feedback Noise MK2 [Re: tfabris]
jfranke
member

Registered: 09/06/1999
Posts: 124
Good I'm not alone with that issue. I've spent the whole day installing the MK1 to my gfriends car (using the grounding wires supplied with the MK1) (plus a navigation system which took 99% of that day...) and then installed the MK2 in my car, leaving the whole installation untouched, now I got the same issue, I can hear the disk spinning up, whatever, strange noises all over the place. I havent changed anything, exept I removed the grounding wires between the MK1 and the amp's, so now the Amp's connect directoy to the MK2. I cannot put them back in since the MK1 is fixed installed and I will NOT take them out again :-)

This noise is definately coming from the MK2, there is no change or alternator whine or anything when I start the engine. Tx, J.


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#10662 - 09/07/2000 09:51 Re: Nasty Feedback Noise MK2 [Re: jfranke]
jfranke
member

Registered: 09/06/1999
Posts: 124
Just to follow up, I have spent the whole day in the garage, trying to fix the issue, in a word, a nogo, very frustrating since the mk2 is unusuable in the moment. Here is what my installation is like and what I discovered.

Front: Single 2-ch. amp directly connected to the mk2 front out.
Rear: A active crossover connected to the mk2 rear out, to the crossover there are 3 amps attached, sub/bass, middle, high.

First, I disassembled my gfriends car again :-( to get the grounding wires back which came with the mk1 which worked absolutely FLAWLESS just to mention it again.

Put the grounding wires in - no change, it even got worse. Now I got a hum added to all that noise, so took them back out.

Started working on the rear amp's. I took out the active crossover and switched on the amp's built-in crossover instead. Bang. Away goes all noise, hum, whatever. Crystalclear sound. Put the xover back in, back is the noise. Checked grounding of the xover, grounding is perfect. The I just connected one channel coming from the mk2 to the xover, and something funny happend - I discovered with just 1 channel connected, the noise comes out of the left and right speakers! Tried the other channel - the same. When I connect both channels, the noise get a bit louder. So to me it looks like the MK2 throws RF via the wire into the xover which might be a bit picky on that.

Then I tried to put additional grounding to the wires, I connected the shieldings of the cables coming fom the mk2 to the car's chassis. No change, but a additional hum was added to the noise. The same effect as there was when I put the grounding-leads at the mk2 (which do nothing else than putting the shilds to the car's chassis, so the same I tried now).

For now I left the xover out, but after all, this sucks big time and I don't know what to do next.

Went to work on the front system. There is just the amp connected straight to the MK2 with maybe 30cm adio-cables. No matter what I was doing, I couldn't get the noise out. Checked all the grounding, all looks perfect.

What is frustrating is that I haven't changed anything in my installations in the first place, compared to the MK1. I really expected it to work without any glitch, and now that.

If someone out there has an idea, I would really appreciate that. Or I have to buy new gear which I don't want. Thanks, J.


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#10663 - 09/07/2000 09:59 Re: Nasty Feedback Noise MK2 [Re: jfranke]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31565
Loc: Seattle, WA
So to me it looks like the MK2 throws RF via the wire into the xover which might be a bit picky on that.

Nah, it just means you've got a ground loop. The more equipment you throw into the mix, the more of a chance you're going to get a ground loop.

Since removal of the crossover removes the noise problem, I'd say you have a difference in ground potential between the crossover and the Empeg (or perhaps another piece of equipment).

Try using heavier-gauge grounding wires for all your equipment, then grounding everything to the same point. Maybe running a ground wire from the Empeg docking sleeve to this same point would help as well. Remember that chassis are grounds as well.

___________
Tony Fabris
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Tony Fabris

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#10664 - 09/07/2000 10:31 Re: Nasty Feedback Noise MK2 [Re: ClemsonJeep]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
As I said before, can you remove the harness from the car and listen to the front/rear pairs (not the home outputs) when powered from the home adapter. If the noise is still present on the 4v outputs, I'm suspicious of a production fault - it sounds to me like the 10v PSU jumper hasn't been fitted, which means the chip that powers the 4v outputs is being powered by the inputs. Erk.

This shouldn't be able to get through the automated testing, but it's a different factory producing the mk2's and I can believe that one person on the line who isn't quite up to speed could make such an error.

Hugo



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#10665 - 09/07/2000 14:34 Action from here.. [Re: ClemsonJeep]
rob
carpal tunnel

Registered: 21/05/1999
Posts: 5335
Loc: Cambridge UK
To the two of you experiencing problems (I hope there aren't more)..

Please do everything you can to be sure that your installation is not at fault, particularly (as Hugo suggested) running the player in the sled at home with AC power. If the car output audio is still affected, there could be a problem with the player.

If this is the case, send an email to me or to [email protected] and we'll take steps to get your player working as soon as possible.

Rob



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#10666 - 10/07/2000 13:31 Re: Nasty Feedback Noise MK2 [Re: altman]
ClemsonJeep
enthusiast

Registered: 09/11/1999
Posts: 398
Loc: Ashburn, VA
As I said before, can you remove the harness from the car and listen to the front/rear pairs (not the home outputs) when powered from the home adapter. If the noise is still present on the 4v outputs, I'm suspicious of a production fault - it sounds to me like the 10v PSU jumper hasn't been fitted, which means the chip that powers the 4v outputs is being powered by the inputs. Erk.

Sorry, I've been busy with work, haven't had much time to work on the empeg. I'll try to remove the chassis this evening and run it off home power and check the front/rear pairs. I'll post when I get more answers.

(O|||||O)

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#10667 - 22/07/2000 10:29 Confirmed Nasty Feedback At Home [Re: altman]
ClemsonJeep
enthusiast

Registered: 09/11/1999
Posts: 398
Loc: Ashburn, VA
As I said before, can you remove the harness from the car and listen to the front/rear pairs (not the home outputs) when powered from the home adapter. If the noise is still present on the 4v outputs, I'm suspicious of a production fault - it sounds to me like the 10v PSU jumper hasn't been fitted, which means the chip that powers the 4v outputs is being powered by the inputs. Erk.

Confirmed. I removed the sled and hooked the front speakers up to my PC speakers. I then put the empeg into the sled and powered it up using the home power cord. If I turned the volume on the speakers up enough, I could hear the same "whine" and "hard drive noise while accessing" through the speakers that I could hear in my Jeep. It is *much* more distinctive in the Jeep though, possibly because the garbage signal is being amplified by a real amplifier and not this wussy PC speaker system I use.

Any suggestions? Is it possible for me to look inside the empeg and see if this 10v PSU jumper has been fitted or not?

Thanks,

(O|||||O)

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#10668 - 22/07/2000 11:56 Re: Confirmed Nasty Feedback At Home [Re: ClemsonJeep]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
I suspect we'd prefer to get it back here for checking. I got exactly this noise when the mk2 went into the miata, but this was because the grounding leads were still fitted (and *very* hard to get to - unbolting access panels & that sort of thing). With the leads removed, it all went away.

If you're still hearing it though, it sounds like a unit fault. Mail Rob and ask him about getting it collected.

Hugo



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#10669 - 04/08/2000 08:05 Re: Updated: Still Noisy [Re: altman]
ClemsonJeep
enthusiast

Registered: 09/11/1999
Posts: 398
Loc: Ashburn, VA
Well, to update everyone. I sent the empeg back to empeg (ha!) and they verified there was a problem with the unit - except I inadvertently caused it at some point. One of the grounding leads from the front output was burnt out, so they bypassed it with a wire. Anyway, I got it back this morning, and installed it again in my new alternator-whine-free installation. I still got the nasty feedback noises, the electronic hum, the hard drive read "ghost sound". Albeit a little more faint, they were still very audible if the volume on the empeg is turned all the way down.

Again, I removed the RCA outputs from the empeg and the noises all went away. Am I still having grounding issues with the empeg? Does anyone happen to know how I can find out if my vehicle (98 Jeep Wrangler) provides the correct ground that the empeg requires (if this sounds like a problem that would be generated by an incorrect grounding)?

Any info again?

I'm at my wits end!

(O|||||O)

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#10670 - 04/08/2000 08:26 Re: Updated: Still Noisy [Re: ClemsonJeep]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31565
Loc: Seattle, WA
Have you done all the installation yourself? Perhaps it's time to talk to an installer?

___________
Tony Fabris
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Tony Fabris

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#10671 - 04/08/2000 08:51 Re: Updated: Still Noisy [Re: ClemsonJeep]
Alan
member

Registered: 06/05/2000
Posts: 142
Loc: Cedar Grove , IN
I'm sure the factory tested the unit thoroughly before sending it back, it might be time to seek the help of a local car audio specialist. It sounds like a wiring problem, a shop could probably have it resolved in 20 minutes. Sometimes when you look at something too long you overlook the obvious and when someone points out the problem you wonder "why didn't I see that".

Alan

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#10672 - 04/08/2000 09:58 Re: Updated: Still Noisy [Re: tfabris]
ClemsonJeep
enthusiast

Registered: 09/11/1999
Posts: 398
Loc: Ashburn, VA
Have you done all the installation yourself? Perhaps it's time to talk to an installer?

Well, most installers don't want to look at custom jobs in the first place... They're probably going to try to rewire the whole thing (no small job) and then charge me out the wazoo for the work uninstalling my work, then doing their own.

I'll keep pecking at it.. I think I have to be close. I've eliminated my alternator whine, which was I set out to do in the first place..

(O|||||O)

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#10673 - 04/08/2000 14:50 Re: Updated: Still Noisy [Re: ClemsonJeep]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
This really sounds like bad earthing on the amps or the empeg itself. It could be that the current demands of the unit going through a bad earth is causing the earth voltage to float up. Have you measured the DC voltage at the empeg 0V point during operation?

You should get the thickest bit of wire you can get hold of (a copper pipe? ) and earth the thing to the chassis with that, making sure you connect to a newly scrubbed patch of raw metal. I really think you must be using the wrong grade of wire here.

To be honest, without a circuit diagram of how you have wired this lot up, this is all guess work. Can you hand sketch a wiring diagram, then scan it and either mail it or attach it for people to look at?

One of the few remaining Mk1 owners... #00015
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One of the few remaining Mk1 owners... #00015

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#10674 - 04/08/2000 15:33 Re: Updated: Still Noisy [Re: schofiel]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31565
Loc: Seattle, WA
Can you hand sketch a wiring diagram, then scan it and either mail it or attach it for people to look at?

And if you do, make sure to include every last detail, including which components are mounted in such a way that they touch the frame of the car, and where each ground point is located on the car for each component.

___________
Tony Fabris
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Tony Fabris

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#10675 - 16/08/2000 12:43 Re: Action from here.. [Re: rob]
Lemmy
member

Registered: 03/12/1999
Posts: 118
Loc: Germany
Hi,

same problem with me here, real bad dirt in the audio when in car, crystal-clean at home...
all the nasty stuff you'd expect and fear in car hifi, rumbling&grumbling when reading from disk, generator whistling multiplied by x when the AC is on and that sh...
just installed two 'dunno how its called in english, it electrically separates the head unit from the amp but lets audio through' just before the amp, now its crystal clean i the car too


bye
lemmy


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--- Mk. I Blue 4G Serial [dont remember] Mk. II Green 6G+20G Serial 080000372

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#10676 - 16/08/2000 13:10 Re: Action from here.. [Re: Lemmy]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31565
Loc: Seattle, WA
just installed two 'dunno how its called in english, it electrically separates the head unit from the amp but lets audio through' just before the amp, now its crystal clean i the car too

You're referring to "Ground Loop Isolators", and they can be purchased at Radio Shack here in the states.

Usually, if you're in a position to need those ground loop isolators, you've got a grounding problem in your amplification system and it could be solved more cheaply just by reworking your grounds properly. But those isolators sure are easy to install, and they do the trick for a lot of people.

Good tip.

___________
Tony Fabris
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Tony Fabris

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