To complete the illusion, we’ll need to brighten up the two synths and separate them in the stereofield.

Rather than using an EQ and a panner separately, Wolfgang seems to have a habit of giving his parts separate EQ curves for the left and right channels. We can approximate this effect by shelving about +6dB at about 2kHz on each of the synths, on opposing channels. The second synth part could also do with a low-pass at about 14kHz but this should be applied to the whole stereo signal.