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Hi Everyone

I have an O76 and for a while now have wished I had bought an O88 instead as i now prefer weighted keys. It occurred to me that if the keyboard in my 76 is a FATAR keyboard, it should be possible ( in theory ) to replace it with the weighted version from FATAR.

Can anyone tell me the keyboard part/model number of the O76 keyboard ? I have had it out already, but can't see any ID, and the FATAR website shows profile diagrams that look similar but I can't tell for sure.

I don't expect it will be a straight forward swap out, mechanically there may need to be some new fixing holes drilled etc, but the 'motherboard' that runs along the underside and the aftertouch strip appear to be preyty much standard in the FATAR range.

It may work out more cost effective than upgrading to an O88, and this way I get to keep my 76 which I know has been well cared for.

Any thoughts or suggestions ?

No, I think it's a Yamaha keybed as was previously used on the high end Tritons. The 88 is a Fatar.

Daz.

I never could understand why a "keyboard" company would use a competitor's keybed,
instead of fabricating their own. I'm sure this practice adds to the cost of the keyboard.
It seems like a common practice in the industry, as far as keybeds go.

If someone could give some insight on this, please do.

The OASYS 76 uses a Yamaha FS Synth Action keybed. The OASYS 88 uses a custom piano action keybed produced by Fatar for Korg -- Fatar TP/31.

With the M3 series Korg started manufacturing their own keybeds.

I would not recommend trying to replace the Yamaha synth action keybed with a weighted action. If you mess it up you are screwed.

Yamaha - Thanks for the information

I will do some research and see if Yamaha manufacture a weighted keyboard from the same range. I have a friend who works for Yamaha music who may be able to get the specs for me.

If they do manufacture a weighted keyboard that uses the same circuit board as the non-weighted, electronically it would be identical,leaving just the mechanical fitting to work out. Alternatively it may be possible to get the FATAR 88 and chop it. ( i've done a similar thing before with a 49 making it into a 44 - an easy job that just required the keys to be unclipped, the circuit board carefully cutting and the chassis butchered! )

I'' do some resaerch and report back.

steve m wrote:Yamaha - Thanks for the information

I will do some research and see if Yamaha manufacture a weighted keyboard from the same range. I have a friend who works for Yamaha music who may be able to get the specs for me.

If they do manufacture a weighted keyboard that uses the same circuit board as the non-weighted, electronically it would be identical,leaving just the mechanical fitting to work out. Alternatively it may be possible to get the FATAR 88 and chop it. ( i've done a similar thing before with a 49 making it into a 44 - an easy job that just required the keys to be unclipped, the circuit board carefully cutting and the chassis butchered! )

I'' do some resaerch and report back.

Remember that Aftertouch is managed also in a different way for 76 and 88 keybeds in Oasys. In the 76 keybed from yamaha it uses one sensor and circuitry seems to come integrated to the keybed I guess. In 88 keybed (the one I have) it uses two sensors for white and black keys separately and signals are then integrated together in a separate circuit thtt is not part of the keybed.
Regarding cutting the circuit...I think you were very lucky!. They never have dedicated lines por each key. They are normally connected multiplexed with each line associated to several keys along the keybed so with 20 or so lines/wires you can manage all the entire 88 keys. Depending on the circuit design cutting an extreme you could affect all the keyboard and not only a part of it...

I am absolutely amazed at the depth of knowledge you have about after touch in the 76 & 88 keyboards. How did you aquire it?

Ken

kenackr wrote:I am absolutely amazed at the depth of knowledge you have about after touch in the 76 & 88 keyboards. How did you aquire it?

Ken

Hi Ken

Leo and I are both good with electronics and have spent years 'messing' around with projects like this. We have both taken our Oasys apart ( for different reasons ) and Leo especially has a good understanding of the hardware configuration.

As Leo points out, there are 2 aftertouch bars on an O88, one for white keys and the other for black, each with it's own control circuit mounted at one end of the keyboard. The O76 has one aftertouch bar and it's control citcuit is mounted underneath the keyboard, hidden from sight, with adjustments on it for sensitivity and gain. On my O76 I moved it to a accesible place for tweaking. My aftertouch was unusable until I managed to make some adjustments - it would fire off modulation etc with the lightest touch. Now it works perfectly.

Leo, on the 49 key FATAR that I chopped down to 44, the tracks that I cut I was lucky that each track went to one key only on the end that was cut off. I wouldn't do it to an 88 until I had seen the board or the artworks for the tracking first. It would be easier to just trade up my O76 to an O88, but it wouldn't be as much fun!

I will try to get some information on the Yamaha keybed first of all and see what looks achievable.

kenackr wrote:I am absolutely amazed at the depth of knowledge you have about after touch in the 76 & 88 keyboards. How did you aquire it?

Ken

I had some issues with the video / screen in my Oasys some time ago so I disasembled my unit and took note of several parts, and signal paths to understand/find the issue.
I had several discussions with the technician from my local technical support also, even checking the technical manuals they have..... plus some Internet research for commercial components as Video AD converter, screen, Hard dirve, motherboard, etc...
but fact is..... I love electronic devices and there is no equipment at home opened and disasembled at least once in its life. I've also worked as PC technician in the past so Oasys hardware is not totally extrange to me

Rgds.

kenackr wrote: On my O76 I moved it to a accesible place for tweaking. My aftertouch was unusable until I managed to make some adjustments - it would fire off modulation etc with the lightest touch. Now it works perfectly.

I did that on my O76 too. I previously owned a triton extreme with the same "firing off aftertouch sensitivity".

Here's a link with the aftertouch board photo's for anyone who might be interested. You can see the location of the board and what it has on it.

http://www.karma-lab.com/forum/showthre ... uch&page=2

I've been busy for a while with work and not had the time to look any further at changing the O76 keybed to a weighted version. The O88 has a FATAR TP/41 which is a variant of their TP/40 keybed.

I contacted FATAR about the possibility of supplying a weighted version that might replace the TP/41, and to my surprise they actually sent me a reply ! It seems the TP/41 has the same electronics as a 'standard' TP/40 but modified metalwork for the keybed mount, so in theory it should be possible to purchase a TP40 weighted keyboard and with some mechanical modifications fit it to the O76. However they can't supply one direct and couldn't reccomend a supplier in Australia, so I'm back to square one. Does anyone know a retail outlet for FATAR keybeds ? Doepfer used to have them but don't have them anymore.

The email aslo mentioned that the TP/41 was not being manufactured anymore, the last being shipped to Korg over a year ago. I guess Korg must have a small stock of them for spares.

steve m wrote: The O76 has one aftertouch bar and it's control citcuit is mounted underneath the keyboard, hidden from sight, with adjustments on it for sensitivity and gain. On my O76 I moved it to a accesible place for tweaking. My aftertouch was unusable until I managed to make some adjustments - it would fire off modulation etc with the lightest touch. Now it works perfectly.

Seems like using the software calibration would be easier, although this requires information only officially available to authorized service centers. You might contact your Korg distributor to see if you can sweet-talk the information out of them. I cannot provide it to you directly, unfortunately.

Have you thought of just getting an 88 weighted key controller?

Hi Dan

I have the calibration procedures and tried that first but it didn't fix the problem. Re-calibrating and changing the aftertouch settings in global mode hardly had any effect at all. In fact during the calibration I could see that the aftertouch cc value went from 0-127 with hardly any pressure applied at all, which highlighted the real problem.

Tweaking the gain of the aftertouch circuit worked perfectly, and in fact after doing that using the global setting actually makes a noticable difference now too. I suspect it either wasn't setup correctly at the factory, or more likely the preset pot had moved slightly. It's not a hardware mod to do if you are not experienced in electronic assemblies though. removing the keybed to get access is a bit tricky, but not impossible.

Before I made the hardware change it was so bad that I had to turn afterouch off in most of my Combi's, now it's very usable.

I am still going to go ahead with changing the keyboard over to weighted if I can find a suitable donor. P/X from 76 to 88 is not an option, way too expensive and there are not many in this part of the world.