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Mini Innofader isn't working as expected? Please read here!

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First I would like to take this opportunity to publicly apologize to everyone who has had trouble with the mini Innofader on the Native Instruments Z2 mixer, DJ Tech DIF-1S, or Thud Rumble TR-1S mixers.


When we first did the mini Innofader production, even though we tested every single one for cut-out and did calibration, we had 2 issues that only became apparent once customers got a hold of the product:

1) The calibration itself had it's own accuracy issues due to the rubber stopper compression and bounce back during calibration. In other words, we didn’t have a precision production test for the cut-in point., and more importantly:

2) due to the shape of the sensor block and the way the block was cut, even with a "perfect" calibration, the mini Innofader had various issues such as large cut-in/cut-out overlap, bleeding, or very large dead space.

On the picture below, the left side shows a first production mini Innofader, and the right side shows a current production mini Innofader which fixes these issues. Then the far right is a bottom view of the PC board. The current production mini Innofader is easily spotted by the circular rivets.




Now before getting into the what we’ve fixed, let’s get into some background on how the mini Innofader works. Here’s an illustration of what the mini Innofader sensor signal should look like, and how we use this signal to do calibration:




The firmware inside the mini Innofader sets the cut-in and cut-out points based on the sensor output at the endpoint of the fader. When the calibration button is pressed, the mini Innofader computes based on that point where the cut-in and cut-out points should be. So you can see from the drawing if the fader block is placed at a different position during calibration, the cut-in and cut-out points are shifted just as well.

You can also see from this picture that since there is still a good signal before the endpoint, it is very easy to recalibrate and shift the endpoint in either direction. To reduce the dead space, the stem can be squeezed against the end since the rubber stopper has about 0.5mm of compression. To increase the dead space, the stem can simply be placed away from the endpoint when the calibration button is pressed.

Now this is what happened on our first mini Innofader production:




The mini Innofader firmware only “knows” the cut points based on the actual signals.  Since the sensor signal has very little change near the endpoint, the calibration had a different effect and resulted in pretty large cut-in and cut-out dead spaces. So in order to maintain a good cut point, we had to “trick” the Innofader calibration by placing a resistor somewhere between 10 and 40 Mohms as shown below to shift the signal. Here’s an illustration of what we did:





If you go back to the very first picture, you’ll notice the original sensor was folded over in the middle. Variations in the folding plus edge cutting were resulting in sensor problems all of varying degrees. In some cases "tricking" the calibration worked fine. But in the case of the sensor used in the above illustration, even a single digital bit offset would shift the entire cut point by 0.5mm or more. Enough to either cause the fader to bleed on one end, or have a huge dead space on the other.




When was this issue fixed?

Actually we fixed this issue in December of 2012. However, some of the older production parts are showing up in recent sales simply because retailers are moving older stock. Again your mixer may be fine with the first production parts - just our newest parts are much more stable and far less likely to have issues with the cut-in.


Will software calibration fix the problem?

Software calibration will fix some issues but unfortunately will not fix this particular problem. The issue is there is not signal change between the end of the fader and the cut point so software calibration can only either make the fader bleed or have a large gap.


Can’t I just recalibrate the mini Innofader to fix the problem?

Well yes to some extent. If you recalibrate the first production mini Innofader, it will definitely fix the bleeding. But most likely the cut-in point will be around 2.0mm and the cut-out around 1.5mm. In some cases the cut points are even slightly higher. It’s OK but not exactly ideal for scratching.

You could do the “trick” like we did in production to pull in the cut-in and cut-out points, but then you’ll drive yourself nuts trying to get a good cut-in without bleeding just like we did.


So what do I do now?

We’ve been working closely with the manufacturers using the mini Innofader and supplying them with new production mini Innofaders to replace mini Innofaders with cut point issues. All of these replacement parts use the latest hardware and are calibrated to have very close to a 1.0mm cut-in and 0.5mm cut-out. The manufacturers are in turn arranging replacements on a case by case basis through their customer support teams.

Please the first thing to do is contact your mixer manufacturer for a RMA. Please don't just start recalibrating and trying to fix things on your own.

All of the manufacturers using the mini Innofader are aware of this issue and are actively servicing it. We have direct contacts with support staff from all companies using the mini Innofader and can push to get your case resolved as needed. While we do not service these mini Innofaders directly, if you contact us at support@audioinnovate.com, we will help bring your case to the attention of the appropriate manufacturer support staff.

You also have the option of upgrading to a full bodied Innofader PNP or Innofader Pro. We welcome your support of our product, but again in no way are you obligated to upgrade. If you contact us directly at Audio Innovate, we will do our best to accommodate you considering the issues with the first production mini Innofader.


So will my replacement mini Innofader really work? How about new production mini Innofaders?

Yes! Since the new design has a much stronger sensor signal, it won’t have issues with the cut-in. Once calibrated in production, the operation is very solid. If you go back to the first picture, you can see that we've lengthened the sensor and used rivets to keep the signal strong all the way to the endpoints and even slightly beyond. This makes the mini Innofader operate pretty much exactly the way we designed it to work.

Maybe at the most the cut point will shift by 0.1-0.2mm during operation. And even so, if you are really looking to get things perfect, it will be easy enough to recalibrate it without all of the weirdness that the original mini Innofader had.

In addition, we now test the calibration of every single mini Innofader to make sure the cut-in is less than 1.2mm and cut-out is greater than 0.3mm. We have found that of all these parts, the overlap between the cut-in and cut-out is between 0.3mm and 0.5mm which is just enough to make the output stable without making the scratch feel sloppy.


How about the mini Innofader PNP? Won’t it have te same issues?

Nope, the issues are also resolved here. The mini Innofader PNP uses the same upgraded sensor technology as the current production mini Innofader. The one major difference is the PNP version is upgraded to have a true resistive fader output so it can work as a drop-in replacement on a variety of mixers and controllers. Plus it allows you to adjust the left and right sides independently by 0.15mm increments. No need to do a full recalibration.


I recalibrated my mini Innofader and now the whole thing is out of whack

If this happens, you'll have to keep recalibrating until the cut points start working on both sides. Again please don't get started with recalibration until you contact the manufacturer of the product using the mini Innofader. The mini Innofader calibration does a sensor level adjustment in addition to cut and middle point calibrations. If the sensor level is off, the calibration will readjust the sensor level, throw away the cut points, and go back to it's original output curve which has a reversing operation near the middle. We do this intentionally to make it clear to whoever is doing the calibration that recalibration is needed.


So hopefully you have found this explanation helpful. Happy scratching!

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