Capacitive Joghweel & random bad ground Issues (no touch detection)

Hi all and happy new year !

For some time now I’ve been using a pair of LC6000s with a Z2 mixer as a secondary setup for stems under Virtual DJ 2023. I often like to babyscratch my incoming tracks and hold the playback with the LC6000 platter in vinyl mode. I’ve noticed that sometimes at random the LC6000 doesn’t detect the touch of my hand. The ring doesn’t turn white and the music starts playing instead of being held which can be very annoying during live performances.

It doesn’t happen all the time but it can happen from time to time. I suspect it’s probably a problem of poor earthing.

At the moment, the LC6000s are both connected only to each of the two USB ports on the Z2, which acts as a USB hub and is self-powered only in this way. I haven’t yet tried using the LC6000’s external power supplies to see if that would solve the problem. But I admit that the basic idea was to do without these additional external power supplies.

I don’t know the output power specification of the Z2’s USB ports and perhaps it’s too limited to power two LC6000s, which could result in the capacitive jogwheel touch detection “stalling” at times.

I’ve seen that earthing mats exist. Do you think this type of mat could be an effective workaround to prevent this kind of problem?

Before spending money on things that may not help you can try the following things:

1.) Make sure you do not have excess static electricity. Once had fuzzy carpet next to the dj stand in my house and that thing charged me like a battery, wrecked havoc with my controller’s capacitive jogwheels.

2.) Additional grounding of the mixer’s chassis. I guess LC units use grounding pins in the usb connectors that is connected to the mixers grounding connection on the power side. If something is wrong internally on the mixer that may help.

Other things to check: outlet tester, change the IEC cable of the mixer, visually inspect the power outlet for bent grounding pins (those round european outlets are prone to that)

Do You have any stickers on the jog wheel?

Surely try the external power supplies - you’ve already got them included - they’re free, might as well

@NoiseRiser No, there haven’t been any stickers on the jogwheels since the day I got them.

@Pasha I’m going to try them to see if they make a difference, but I wish I didn’t need the extra power supplies.

@SlayForMoney I’ll check it all out. I’ve noticed that this doesn’t happen when I have my other hand on the mixer (the chassis is metal). It’s a pity that the LC6000 isn’t simply fitted with a ground screw like the vinyl turntables. I would have just connected them to the ground screw on the Z2 and I think that would have been enough to get round the problem.

As I mentioned, usb connectors have a ground pin in them. But it’s enough that one of them in the usb chain is bent a little and it can cause problems like this. If both LC units have that problem I would inspect the mixer primarily. Usb cable and port and then on the laptop side usb port. Make sure the GND pin is not corroded.

As Slay says, it looks like it’s an issue with the device that the LCs plug into. Try the mains power cables as a short-term fix like Pasha said but to use less cabling I’d look down the USB chain as to where the grounding seems to be failing. It could be a hub, mixer or power issue that isn’t passing the ground though it.

I’m going to check it all out

The ground problem in my experience presents as an overly-easy means of triggering the touch… as in your hand hovering an inch over the platter and it triggers the touch. If you’re in a venue that stupidly has no ground connection that’s probably in violation of some code, you just don’t put your hand over and near the platter unless you want to trigger the vinyl mode. I DJ’ed a several hours NYE silent disco all by-ear that way without any big issue. You just jog bend without your palm over the platter, fingers coming at it from the side, instead.

Another issue is the plastic dust from the tension mechanism being utilized (you shouldn’t use the tension mechanism and should instead set them to minimum) gunking up the electrical contacts in there, but that has previously presented as the touch triggering rapidly on its own even with your hand no where near. I don’t know if the LC is susceptible to the same issue or a variant of it.

While I personally only have the 5000s, the only time I’ve ever heard of issues with a lack of touch response is the stickers still being on the jog or major jog wheel malfunction that requires servicing.

In contrast to the 5000s, do the 6000s’ jog problems frequently present as less touch sensitivity rather than more sensitivity during issues that can be user serviceable?

There’s been a firmware update for LC6000. You might need to check that out as well. If you haven’t already.

What’s the latest firmware version for the LC”s? What is the best way to update them? Can you update them when attached to s Prime 4

See under controllers on Software downloads, manuals and documentation - Denon DJ.

Install via USB-cable on a computer (Win or Mac).

The most recent firmware for the LC6000 consists of two parts: controller firmware: 00.31 display firmware: 00.50

both are installed at the same time when updating with the Denon utility.

Note that in my case the firmware refuses to install if both LC6000s are switched on and connected at the same time.

You need to turn on only one at a time and update one then redo the update on the other.

Did it solve your problem btw?

Not really, the update didn’t have any impact, but I have to admit that I haven’t taken the time to investigate further. I did a two-hour mix yesterday and for more than an hour and a half I had no problems at all. Then in the last half hour the jog on my right LC became erratic in detecting the touch on the surface. Sometimes the left one does it too in certain sessions, although that wasn’t the case last night. I haven’t tested the mains adapters yet as I need to buy an extra power strip.

I changed the IEC cable on the mixer but that didn’t make much difference either. I’m pretty sure that it’s not a hardware problem with the mixer or the LCs but a problem linked to an external factor, the environment or the conditions of use (perhaps linked to wearing synthetic clothes).

I think that if it was linked to a hardware problem the problem would be systematic and not random.

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What added functionality does the update offer?

Nothing at all, just a generic update.

I’ve come to bring you some news,

I was able to test my LC6000 at another location with another mixer and another computer with the same USB cables and I had no problems. So I think we can rule out a malfunction of the LC6000.

I’ll be receiving my new laptop for my mobile events in a few days’ time. I’ll see what happens with this new machine and the Z2. I think the problem certainly lies in the environment of my fixed PC. Maybe a problem linked to the USB ports.

Interesting…. This could make a huge difference to lots of others issues with their gear too.

Could you get hold of one of them earth wrist bands that electrical engineers wear and see if that improves it? I’m convinced that static on the platters is the root cause, it makes the most sense as it’s so easy to generate it by simply wearing the wrong clothes or stood on a certain type of flooring.

my freaking old ass house isnt grounded and iwould have been screaming bloody murder if I didnt get my 5000s motorized.

my neighbours prime 4 would lose its marbles when you would turn on vinyl mode…but only on the left deck lol.

you could watch the led ring give you a light show from all the ghost touches on the platter.

Certain places where grounding is key…this is unfortunately one of them