This dirty kind of lead sound

Sound like a sawtooth with filter to me.
Did some experiments, see attached patch file.

PS:

• IMO, the second patch which doesn't have any detune set for OSC 2 is closer to the sound in the example song
• The ARP is set up so you can preview to sound with a part of the the Atron lead line, just activate the ARP and hold a F# in the middle octave.
• Aftertouch and Mod Wheel control the detune of OSC 2 which allows you to modulate the sound like in the example song

Enjoy, and let me know what you think!

Zitat von pequalsnp

After I finally discovered I had to turn on the arp (I was wondering why the keyboard was transposed so high)

Yeah, sorry, I forgot that the sound has an odd transposition if the ARP is used as step sequencer and switched off.
I uploaded a new version of the patch library, two patches with ARP and two without.

Zitat von pequalsnp

my mind is blown. Good job on the patch and this use of the arp was an eye opener for me!

You're welcome
I always try to learn more about synthesis by doing recreations of sounds.

Zitat von pequalsnp

Do you have a cheatsheet on how the velocity values in the arp map to notes (given arp input->transposition is at +64 like in your example)? Thank you very much, highly appreciate this!

If in the Matrix the ARP Input is routed to Transpose with a value of +64, then each velocity value in the ARP corresponds to a MIDI note pitch. The velocity value of 64 of the ARP velocity corresponds to "no transposition" and plays that note that is held on the keyboard. The value 52 (64-12) yields an octave below, 76 an octave above (64+12). That way, you can use the Virus ARP as step sequencer for melodic sequences.

However, there are a couple of caveats, one being that if you switch off the ARP, the sound will often be transposed by to and odd pitch because of the Matrix still doing a transposition even though there is no ARP input anymore. The other is that the pitch and velocity are hard hard wired. Also, the 32 steps are quite limiting for faster lines. That Atron lead melody would need 128 steps for the full melody.