Nord Electro4D Drawbar "Clicking"

[doneanes]

Hey all - Maybe I'm just nuts... but doing a session today we noticed a small, but audible, clicking when moving the drawbars. Never noticed it before. It kinda resembles the key click? But it was enough to be annoying. Almost sounds like ratchet drawbars - kinda - if that makes sense? Hit me back or try it for yourself, and hit me back. It should be noted, I own two B3's and a Model A. So I know what playing the real thing sounds like. THAAAAAAAANNNNKKKKKS! D

[Cornopean]

Logically speaking, if you move a drawbar, you change the waveform. There will therefore be a discontinuity between the immediately "before" and "after" samples if emulated on a basic level. Careful programming (by Nord) should minimise this by, say, changing the waveform gradually over a few milliseconds. On an analogue electric model, the switch between drawbar levels would naturally have some buffering from the rise time of the components.

Presuming of course that the noise is not mechanical. I have a 4HP so can't check. Previously owned an A105 so also know what the real thing sounds like.

[Nordlicht]

Hi,

I have a C2 and checked this "draw-click".
When "pulling" a drawbar/button continuously from 0 to 8 I can also hear some kind of "click" or "contact" noise. If I "pull" step by step this noise is nearly inaudible.

My explanations:
If you move a drawbar you actually change the volume of this tone (and as far as I know there a no samples used in the Nord organs).
So with each drawbar step the volume is increasing in a digital manner, i.e. also in steps and not continuously. And perhaps this noise is a result of some software/program behavior (some kind of "switch-on effect").

I can't check if this also happens an a real Hammond organ, but when playing "normally" this very soft noise should be no problem.

[anotherscott]

I noticed this in the past, when using external drawbar/fader control on a drawbutton Nord. It is not universal to all clones (I don't think I"ve heard it on any other), and I do consider it a slight drawback of the Nord implementation. It is conceivable that Nord is specifically emulating the behavior of older tonewheel organs, but that doesn't make it desirable.

from http://www.dairiki.org/HammondWiki/Drawbars

In early Hammonds, drawbars were originally Ratchet type with distinct detents at each setting. Adjusting the drawbars on these models causes an audible pop as the contacts open and close. Newer organs have the more desirable Smooth type which do not have distinct detents. To eliminate this noise, these drawbars were constructed as make before break switches

[Cornopean]

To avoid any confusion, as Nordlicht appears to have misunderstood, when I refer to samples in my post above, I am talking about moving from one sample to the next in the output waveform, and nothing to do with "sampling" as in sampled pianos. Nords are digital emulations, and thus prior to the D-A converter, the output is a continuous series of digital samples at 48kHz or whatever frequency Nord have decided upon. The organ is indeed emulated, and I have programmed Hammond emulators in software before.

And to comment on his explanation, each separate drawbar has a different waveform (almost sinusoidal) with its volume controlled by the drawbars in a number of discrete, non-continuous steps. These are added together into a single waveform for each note. Basic Fourier theory tells us that a sudden change in a waveform will correlate in the frequency domain with a noise-like click, hence my comment that careful programming would change the level of a waveform over a few milliseconds rather than instantaneously.

So in other words he is saying broadly the same thing that I did, without quite realising it.

[doneanes]

Hey Fellas! Thanks for the replies! I think... it's just the "key click" on the Nord. I dig it. But I didn't think it would be present when holding down a note and moving a drawbar from 1,2,3,4,5,6,7,8. If anybody has a Nord Electro4D, I'd love for someone to check it. I hear it even through the headphones. I can control the volume of the "pop" by turning the key click up or down. Not the end of the world. I bought this thing sight unseen and unplayed. I got it because it had drawbars as I'm playing a B3 90% of the time. But this thing fits on a plane when needed. And it sounds killllllller through a Leslie. I love the Nord! Thanks again! Don

[OBDave]

A real Hammond does this too. Just as key click occurs when you engage and disengage the key contacts, when you move a drawbar in and out there is a perceptible click as busbars engage if notes are held down. This is true of the newer (post ~1953) Hammonds with smooth drawbars. The older ratchet drawbars had a break-before-make mechanism so the drawbar harmonics would drop out when moving a drawbar with notess held down.

So the thing you're hearing is Nord's emulation of how smooth drawbars operate.

[JiminWales]

I've noticed this on my E4 but also get flutters of "zipper noise" on other controls, so I'm not sure if it's emulation of original hardware or a DSP flaw!

[Cornopean]

When emulating a Hammond in Pure Data for a class I taught, I noticed that type of digital discontinuity click on key-on. So I created something that ramped the onset anywhere from 0 to 5ms and called it "Key click amount" - nothing like turning a bug into a feature

[doneanes]

Yeah, through my Leslie live it's fantastic. I spent quality time with my 4D last night and freakin' love it! Would've been great if they had added one more option for the keyclick as in [Off] instead of [Low] being the last option... maybe in an update! Have a rockin' week! D