A little more experimentation and I’ve found the ADSR envelope stays almost flat with all sliders down if it’s triggered via a 5V gate to the Gate input. There is still the tiniest bump when triggered this way, but nothing close to the effect of the manual gate button. Triggering via MIDI seems to behave more like pressing the manual gate button.

The other interesting thing I discovered is that the LFO ‘leaks’ into the VCO1 FM mod, even with the vibrato depth and LFO FM mod on VCO1 all the way down. The solution is to plug a dummy patch cable into the “Ext Vib In” input. This seems to break the normalling of the LFO in the right place to prevent this leakage (plugging a dummy cable into LFO FM mod on VCO1 didn’t work, which must say something about the signal path the LFO is taking to leak into the VCO1 freq modulation).

One thing I’ve noticed about the 2600 (and I doubt this is unique to the BARP clone) is there are a lot of signal paths that aren’t buffered or isolated like you might expect in a heavily engineered Eurorack module or modern semi-modular. Sometimes it provides interesting character, other times it shows the compromises of it’s age and feels a bit broken by modern expectations.

I tested this on my Behringer 2600 and got similar behaviour, so I suspect it’s a quirk if the hardware, (one that is possibly not emulated by the Arturia VST). One way around it seems to be to patch a gate into the ADSR gate input instead of using the manual trigger button - try patching the internal sample and hold clock into the ADSR gate input, and the envelope stays flat until you raise some of the sliders.

I wonder if it happens when you trigger via MIDI ? (I didn’t test) Patching the KBD gate or trigger from the left hand side into the ADSR would be an option to try too.

Roucha Legio looks interesting - a good balance of features in a fairly small space. I’d sort of stopped paying attention to all the new Legio modules, but with so many options now, the ability to just swap the firmware to try one out is becoming pretty compelling.

I would suggest as a starting point maybe just start using the FX Aid XL and Morphagene with your current gear, make some sounds and start to find what’s missing. When you think … "I’ve really love to be able to … or “I would really like to tweak this VCV rack module in hardware”, then find a module to help fill that function. This will give you time to learn and master the new things you have before adding more.

RE Ochd vs Maths - even though it’s a bigger footprint for less LFOs, I feel like you might have fun with all the interesting generative feedback type patches you can do with Maths given the style you are aiming for. It can even be an extra (non-V/Oct) VCO for drones. Maths does take a bit of time to learn and understand. Another interesting module in this space (which I don’t have but very much want) would be the After Later QARV. Or Pams New Workout - lots of modulation options beyond simple LFOs, but not everyone’s cup’o’tea since it has a screen and some non-divey menus.

No specific suggestions for a filter, but it makes sense to have one given your existing gear. If you are going for a stereo signal path, I’d suggest a stereo filter since you can get some great spatial effects by modulating channels independently.

With regard to Befaco Out, it could be worth looking at small stereo mixers as an alternative, especially one that lets you attenuate the master output level, since this could go straight into your line-level speakers/computer.