The PPG Wave 2.3 was released in 1984 and was the last PPG wavetable synthesizer that went into production before PPG went into financial problems in 1987 after having spent a lot of time and money to develop the PPG Realizer which by many is considered the forerunner of VST technology as it was able to virtually emulate other synthesizers.
This being in 1986 with an estimated price of 65000 USD. Only two prototypes were made.
The PPG Wave 2.3 is a very nice sounding 8 voice / 2 oscillators per voice wavetable synthesizer with eight MIDI channels and a lot of different ways of stacking and splitting the eight eight possible simultaneously sounding programs.
In many ways it sounds like a PPG Wave 2.2 but having the extra PPG Wave 2.3 mode allows you to stack, split or play eight PPG Wave 2.2's at once (each one with one note polyphony of course).
It also spotted eight separate outputs - one for each voice - and had factory installed MIDI In / Out and Thru from the very beginning (this was 1985 and everything HAD to have MIDI :-).
Adding the MIDI code to the PPG Wave 2.3 also did something else - it 'destroyed' wavetable 13. Well ... Destroyed is a hard word, but no doubt it sounded different after MIDI was added.
Hermann Seibs V8.3 OS for the PPG Wave 2.2/PPG Wave 2.3 fixes this issue (and does a LOT of other VERY cool stuff as well), so I would definetely recommend you updating your PPG Wave 2.3 to V8.3 - available from Virtual Music in Vienna.
The PPG Wave 2.3 is also the most common of all PPG synthesizers these days. Approx 700 were made compared to the PPG Wave 2 and PPG Wave 2.2 (not to mention the 360 Wavecomputer with only approx 40 made).
The 'problem' with getting your hands on one of these units these daus is the price tag they come with.
I have seen these units go for around 2500 euro on eBay lately !!