Two very useful module types for hexaphonic/multichannel guitar processing:
Compression and Pedal I/O!
Below is a photo of what I use in the SynQuaNon Eurorack research case - three each of the following:
- WMD MSCL Stereo Compressor (4HP each) - knob.farm Ferry Two Channel Effects Send/Return (4HP each)
The WMD MSCL Compressor is built around the THAT Corporation 4301 Audio Engine and very high quality low noise circuitry, only commonly found in pro studio gear. The sound quality is outstanding!
The knob.farm Ferry is a fantastic effects send/return module. It takes care of all level matching between pedals and Eurorack, is also ultra low noise and has a variety of great features. I really like using the wet/dry mix controls on this module.
I recommend putting the MSCL Compressor in the audio chain just after the guitar input:
A) 13-Pin Input Breakout > MSCL Compressor B) Nexus Input Breakout > 7-Channel Amp-Attenuator > MSCL Compressor
The Ferry modules can go just about anywhere in the chain; I've experimented with inserting distortion pedals just before the VCF. One can add modulation pedals (delay, reverb) at the end of the chain. How about guitar amp simulator pedals right after the input? The possibilities are endless. While there are numerous great Eurorack modules for most effects, sometimes it's appropriate to insert a special pedal effect!
Now you can have your pedalboard inside your Eurorack case! Absolutely wonderful!