hello, i just wonder if the a4 would be a good addition to my virus c and my digitakt.
as i don’t know what the a4 offers on the synthesis side i really curious about your experiences
with this machine.
what can i do with a4 beside subtractive and additive synthesis?
i read that it can’t do real fm where one osc modulates the freq of another osc but instead i can
use freq limited lfo.
or that i can’t achieve cross modulation where 2 osc´s modulates each other…
is that right, even with the current os and the mk2?
It‘s a subtractive synth with lot‘s of modulation possibilities. There are crossmodulation features between the oscillators, e.g. Am.
There is oscillator sync and an oscillator feeback, that is pretty crazy but I don‘t how that works techniqually.
You can do fm via key trackable lfo‘s, but it not easy to handle, at least that‘s my experience
You can also do some karplus-strong synthesis with the chorus effect and it sounds kind of cool. here’s a minute of me screwing around with that. Starting from a blank kit, turn track 1s amp envelope sustain and decay all the way down, chorus send all the way up, then put in some trigs on track 1 to make a rhythm. switch to the FX track, go to the chorus page, and turn feedback all the way to the left or right (two different flavors) and p-lock everything else. If you turn spd and dep all the way down, pre will correspond to pitch. I start by sequencing a melody with that then affecting the sound by playing with the other params and sending some of it to the other FX.
edit: also, on track 1 make the filter env short and plucky and modulate the filters with high resonance for more variation. Also if it’s too clicky for your taste turn off the dry trig sounds from trk 1 in the voice routing menu.
If you have eurorack, there’s the Verbos harmonic oscillator. Kawai k5000 is sort of vintage but its sort of modern, but discontinued. It does additive.
Wow that was fast, thanks a lot I try to stay away from modular / eurorack, but I use Reaktor as a substitute Will check out the Kawai. Would love to see some new way of additive synthesis in form of a Hardware synth!
so it is possible to mod osc1 freq by osc2?
And regarding feedback, did you mean two osc feedback or even one osc feedback, where the osc output is fed back into its freqinput?
@helloliamdaly
thanks for taking the time! just listen to it via headphones. sounds great. iam just using digitakts delay fx with very small delay tine and feedback at 100 % for something very similar. btw. how do you like the effects of the a4?
Please somebody correct me if I’m wrong, but to my knowledge: Frequency modulation of an osc at audio rate is only available via the fast speed settings on Lfo’s, not via another osc…
Regarding feedback (which you select under Osc waveforms of Osc1), taken from the manual:
“FDB This setting is only available to OSCILLATOR 1. Instead of using the oscillator waveform as the audio
source, the audio coming from the ladder filter output will be used. Just as with the oscillator, the LEV parameter sets the level of this signal path. Turning it up high can introduce a self-oscillating feedback useful for drums or uncontrolled screams. The filter cutoff and resonance settings also affect the feedback behavior. On more moderate levels, it will give a more overloaded sound character to whatever enters the filter from OSC2, similar to the external feedback patch known from certain 1970s synths.”
On their own, the delay and chorus are fantastic, the reverb is usable, BUT when you take into account that every FX parameter is 100% p-lockable and the FX have their own sequencer track with micro timing, parameter slides, trig conditions…they’re out of this world.
Regarding Oscillator crossmodulation, these are the options (manual again). You find specific threads to AM, feedback etc. on this forum, with great information!!
"AM1 (Osc1 AM) engages Amplitude Modulation on Oscillator 1,
which means that its signal is switched on/off (multiplied) by the
pulse wave of Oscillator 2. This introduces new harmonics with
frequencies being the sum and difference frequencies of the harmonics
of the two oscillators. The result is related to ring modulation
and can give metallic, hollow, or disharmonic sound
qualities. Note that the waveform and pulse width of Oscillator 2
also affects the result, even if that oscillator is not heard.
SMD (Sync Mode) enables oscillator sync between the two oscillators,
either Osc2 synchronized to Osc1, Osc1 to Osc2, or Metal
Sync where both oscillators reset each other in a special manner.
SNC (Sync Amount) sets the amount or “hardness” of the oscillator
sync, meaning how hard the synced oscillator will lock to
the syncing oscillator’s frequency. Maximum value gives socalled
“hard sync” with the strongest sync sound. Lower values
gives “soft sync” where the synced oscillator can lock also to
subharmonics of the syncing oscillator. The value zero gives no
sync at all."
AM works also in opposite direction. It’s one of my favourite features. Can give you many, non subtractive-typical sounds…
Yes that’s correct regarding ‘pseudo LFO FM’ of the A4.
The LFOs are taken into audio rates and tuned at musical intervals relative to the modulated oscillator.
It sounds better than nothing, but not like real OSC FM
thanks. @Unifono opposite direction means osc1 modulates osc2? or did you mean something like the polarity?
btw i just find this ampmod a4 example which sounds pretty good. very organic. something that reminds me of physical modelling:
all i could found is, that you can use the ext input as the waveform of the osc. but this will replace them and route the ext signal into the ladder filter…
I try to stay away from modular / eurorack, but I use Reaktor as a substitute 
Will check out the Kawai. Would love to see some new way of additive synthesis in form of a Hardware synth!