Nord Stage 3 88HA "LED ghosting" issue

[cgrafx]

The ghosting your seeing is caused by a small amount of leakage current in the LED display matrix circuitry. It really shouldn't be there, but its also not something I would be overly concerned about. Its very probably present in a lot of units and there is no guarantee it wouldn't be present in a replacement keyboard.

On the other hand, Nord really should be responding to you with a proper answer.

[Hlaalu]

Thanks for the feedback.

I am too kind of doubtful whether to ask for a replacement or not, given the nature of the "issue". It took me two weeks to notice it the first time, and of course functionality isn't affected. But given the value (economic as well) of the machine, one does wonder.

Now, IF this ghosting thing is limited to what it is, I don't really mind. But if it indicates, say, a broken component which might create other problems in the future (such as, say, a fried LED), this is where I'd really like to have an answer from Nord, and consider asking for a replacement.

I hope to get a reply soon from Clavia...

[Hlaalu]

In case anyone was wondering how this thing has evolved, I am still waiting for a reply from Clavia.

I sent THREE support emails, specifying (as they ask you to do) that it was the second and then the third time I was contacting them, respectively. No reply at all. Last attempt was a month ago.

Thomann, on the other hand, says that without a proper explanation from the manufacturer, this behaviour can be considered normal and thus they won't be servicing the instrument -- which is understandable.

I think I am giving up and keeping my NS3 as it is.

[stageCustom]

Hi,
thanks for your video. This is just one of the hard to avoid "dark sides" of digital electronics.

What we can see in your video and as you wrote, is, it needs to be dark to recognise the ghosting LEDs. Under daylight you probably won't see much if anything.

Technically spoken the ghosting happens because a little excessive voltage appears across the two pins of a LED. These are probably just a few 100 mV, which is the order or residual variations e.g. on the internal ground-wiring. (The circuit on the other pin has an impact too, but let's keep it "simple".)

Ideally there would be a big ground plate inside the NS3 where alle internal ground connections are connected to in a central (star-like) way. For geometrical and economic reasons you simply can't do it - just think of 10 internal modules which have to be connected somehow. Instead you'll have a distributed ground-network, which is far from the ideal zero-ohms impedance. Hence you'll have effects as you filmed.

Digital electronics, especially in power horses like the NS3, create so much rumbling noise on the ground-network (and on the internal supply lines and somewhat on the internal signal lines), that's it's close to infeasable to reduce them all in any of the myrads of operating situations.

Now, even if you use the same LEDs as a manufacturer, there still is some variation amongst them. Some will need little and some will need higher voltages (a few 10 mV - 100 mV) to give the same amount of light. So from NS3 to NS3 ghosting can appear on different LEDs, ranging from "none to report" to "yes, but in a different pattern".

So in summary I'd consider it more of a "cosmetic problem". It's nasty, it doesn't really hurt and it's technically hard to avoid.

(However, from my professional background I'd offer willing companies assistance. Tiny changes in design can have big effects, and most systems do have the potential to perform much better. However, engineers forgot how to do it or can't care about this. And no, time and effort are just no arguments: They are only valid, if engineers do, what everybody does. Which isn't bad, but many times is not enough. And no, I have no relations with Clavia Nord

[Hlaalu]

THAT is the kind of answer I wish I had gotten from Clavia. Thank you so much!

I am not an expert in electronics, but in the meantime, searching in Internet forums about electronics and LEDs, I had more or less imagined what you said.

Maybe a comparison to this LED ghosting thing (albeit a bit imaginative) would be this: to search for a knot-free piece of wood to then make a piece of furniture with. Theoretically possible, and if you are really committed to it you'll eventually find a big enough wood board which is knot-free, or a machining method to level them flat out, but most of the time that's hard in practice and not really worth the effort. You judge if that's a good metaphor or not!

Anyway, case closed I guess. Thank you all


ALSO: I have to admit, even in a dark room, it's not something I notice casually, even now that I know it's there. I have to go physically close to the LEDs to see which ones are ghosting in that particular configuration. So anyway, a minor problem but there's nothing that gets you more picky and fastidious than a € 3,500 piece of machinery.

[stageCustom]

THAT is the kind of answer I wish I had gotten from Clavia. Thank you so much!

You're welcome Happy having helped you along

BTW, your wood-example is an excellent alanogy.

[cphollis]

My Stage 3 "ghosted" for a while -- random flickering of LEDs and other displays. The sound didn't change when this was happening, but geez it was annoying in the middle of a gig. So I changed out all of my cables (audio, MIDI, pedals) as well as started to use a regulated power supply.

I can't tell you which specific action cured the problem, only that it's not a problem anymore. Bottom line, I convinced myself it wasn't the Nord, it was something the Nord plugged into that was causing the problem.

[Hlaalu]

My Stage 3 "ghosted" for a while -- random flickering of LEDs and other displays. The sound didn't change when this was happening, but geez it was annoying in the middle of a gig. So I changed out all of my cables (audio, MIDI, pedals) as well as started to use a regulated power supply.

I can't tell you which specific action cured the problem, only that it's not a problem anymore. Bottom line, I convinced myself it wasn't the Nord, it was something the Nord plugged into that was causing the problem.

Thanks for the feedback. Now that I read though, I am not sure my problem is comparable to this. My displays are definitely not lighting up by themselves, nor are the LEDS -- at least not in the sense that they lit and then shut off again randomly.

In the dark I see some LEDs on the panel very dimly on, but this doesn't change with time, they stay on. This is how it manifests itself for me.

Anyway by regulated power supply do you mean you are plugging it to a UPS now? I was looking for one, but online-type, true sinewave UPS' starts from € 250-300 (or possibly $).