Spent some time/thoughts to built a (to my ears) convincing acid patch. Shared a few sounds over here:
Let’s hear what you say! 
The long read
A few details about design choices made that may be of interest:
- All 303 demos I looked at had a steeper exponential volume curve when using accents, which is most likely due to the distinct circuits for vca and accent. I tried to achieve a similar behaviour with two envelopes and the steeper one kicking in when increasing velocity.
- Saw wave is actually TRI with PWM set to max either left or right. This makes a little dirtier sound than just using SAW.
- Square is OSC tuned +12 and uses only the SUB -1 OCT. Simply because this is a more symmetric square wave.
- You could easily use filter 2 set to hi-pass to reduce bass frequencies a little, but I came across a different trick that sounds nicer: Set filter 2 to 24db hi-pass leaving it completely open and crank up envelope DEP to around 32.
- There’s some meowing possible but hardly any of the fierce dog’s bow wow.
