Here are all available Pure Data Filters collected as automatonism modules in action:

In your Boca Ladder abstraction i mixed the normal tanh with the analog clipper,which in my opinion gives the best results. If in exp~ the quotient is ==5 , only analog clipping is used via switch. if both mixed are together the sounds gets some superb irregular resonances. the bite parameter in the module amplifies the resonance:

i also spent a oversampling switcher for 2/4 *oversampling, where with 4 OS the snapping of modulation sources sounds greater
imho.

Here is the test-file
Battle of the filters Vol.zip

Im late to the party. But for all it's sins Bob~ retains very clear transients, something that real analogue filters do very well too. Horses for Courses. I abso love the filter implementations above and they sound great in context, but this week trying them as a sub for bob~ in a fast transient environment, they smudged every thing thrown at them. Sure Bob~ sounds thinner but I found it more musically useful in fast percussive situations. Also has better pronounced resonance. It depends on the musical context. I love the Matrix 12 filter implentation, mind blowingly good. Now me thinks, with the wonderful wizardry displayed in the above filters has anyone attempted somethin in the class of the Pultec EPQ-1. By listening to the examples above, Im sure it could be done

@Element-S I can't help you with the Pultec EQP-1 implementation, but since you're talking about being late to the party it might be worth pointing out that at least some of [bob~]'s weaknesses, mentioned in this thread, may have been the result of a bug, that was fixed around three years ago. If I remember correctly, the output wasn't taken after the fourth stage of the filter but before the first (= input + feedback). So no surprise, that this was considered a bad implementation of the Moog ladder filter.

Edit: Had to look it up ... It was actually a bit different from what I remembered: The incorrect output was the first instead of the fourth state variable. So the output was taken AFTER the first stage.

@Element-S said:

I love the Matrix 12 filter implentation, mind blowingly good.

I have been meaning to update that for awhile now, greatly improved the resonance and distortion characteristics but need to put in some time to cut some of those improvements so cpu usage is sane, there is a balance in there somewhere. Will see about finishing it up tonight/tomorrow and will upload it in the polemix thread.

somethin in the class of the Pultec EPQ-1

I kind of like that idea, the fixed frequency bands of the EQP1/MEQ5/old passive EQs and mixers has always appealed to me, I like the workflow. I might play with this, maybe have something up next weekend. Never dawned on me to implement a passive mixer with all of their quirks and limitations in pd, would be a nice break from the DAW and its endless tweaking, getting the cross talk between channels right might be a trick and is a must to make its simple switched left/center/right panning work. Sounds like a fun project, 1930s style studio in pd.