Hello,
I’m thinking of buying an A4.
If I play a sound with a chord of 3 notes, does that means I can only add 1 sound of I can still use the 3 others voice?
If the chord use the other voices, how it works? How I chosse the voice which are “disable”?
Thanks.
The manual has a whole page explaining this. But since I had it open at that page just now I’ll give you this little excerpt to get you started…
Four voice polyphony can be configured by selecting POLY CONFIG in the KIT menu. The Analog Four
MKII is capable of four voice multitimbral polyphony (or unison). This is possible due to the powerful sound
engine which is able to change sound instantly and allow completely dynamic voice allocation (see figure
below). The sequencer is fully polyphonic, allowing overlapping notes and chords to be programmed on the
tracks. Any track can play up to four notes using its track sound. Notes are distributed to the synth voices
according to the selected allocation method. Any of the synth voices can also be poly-disabled, allowing
tracks to have their dedicated, monophonic synth voice available at all times.
At any given point in time 4 voices can sound simultaneously. There are different configurations for voice allocation/stealing. The manual explains this in detail. To answer your question: if you play a three note chord, you have one voice left. It’s worth pointing out that you can work around this by building your chords using a detuned OSC2 and the sub oscillator(s), which gives you 4 different pitches per voice.
You COULD opt to set up a single voice setting the oscs to 2 different notes, and use the Sub-Osc of each/either to a 5th and you could have upwards of 4 different notes on a single voice.
You might need to do p-locking to configure the right notes per step, but that might help in a pinch.
It simply have to be unchecked in poly setup. The 3 other poly voices have to be checked.
Beware of long releases. It can steal voices.
I don’t especially like Subs for chords, as I don’t especially like square waves, but it can be used indeed.
Thanks everyone for the answers!
I suggest to consider what is “polyphony” to you.
At a minimum this would be two complete synth voices … well 
If you can live with four voices of an A4, which has sub-oscillators per voice too, the A4 is it. But it’s limited to four voices. Any chord of 4 voices would not allow a fifth note to be played, even if the A4 has an intelligent voice allocation concept.
If you want to create classical - thick - long lasting- ever changing - polyphonic chord pads, I would suggest to check out synths with eight or even more voices.
You could trick the ear, by setting the 2 Osc pitches plus Sub-Osc pitch all to different values per step.
This was always a special feature of the A4 … to have the subs go not only an octave below but a 5th too. Wouldn’t be tricking the ear … would be true