Korg Poly800 filter modification

With this guidance also an inexperienced electronics engineer can modify its Synthesizer.

This is my Korg Poly800 with in the following explained filter modification. Over the Korg typical " Joystick" are good the potentiometers for cut off and Resonance to see. The material is not expensive and lies with nearly each hobby electronics engineers assortment. One needs two potentiometers with in each case 10K and 100K, 1m thin cable and a calm hand with soldering and boring.

Note: I point here again to refer to which happens the modification on own risk and I do not take over a warranty for this change. I made the change and tested the function. Small interference, large effect!!!

Step 1: Housing modification

The housing screw on and then the plate with the joystick remove. Over the joystick sufficient place is to be inserted around the two potentiometers. After one is safe of 100%, to know which one does, can one as in the picture see the two holes to bore. Hint: Only with a thin drill pre-drill.

The potentiometers can be now used. This concerns a 10k potentiometer for the Resonance and a 100k for the cut off. For the easy wiring, which is described later, the Joystick should not be inserted yet again.

The layout was provided simply with a text processing or a like, fixed on paper printed and with a transparent foil.

Now a few beautiful buttons still select and the modification of the housing would drive through the potentiometers insert and are terminated nearly finished already the change.

Step 2: Soldering

The modification filter consists of it, the trimmers for the attitude of point of work ice of cut off and Resonance to replace by potentiometers. We look for the large green motherboard and find here the trimmers VR5 and VR6.

As on pictures to be seen good, the trimmers are replaced by thin cables. This work must be accomplished with extreme care.

HINT: Since the trimmers sit still quite firmly also without tin solder, and a destruction of the plate to be avoided must be destroyed, should the trimmers and the pins einzelnd to be expenditure-soldered.

Step 3: Wiring

Now the cables can be connected be inserted to the Joystick with the potentiometers on the front plate and again.

Now the cables are brought still with cable strap into a form, so that block when the assembling housing avoids becomes. The cables of the modification are hardly to be differentiated now from the original wiring harness to.

Now the housing must be screwed on only and already to play!!!

Much fun with the change!!!