@Hikove - that's a very good question - I've not built mine (which are the 3hp ones btw) - but I am intending to use them with a es8/es6 combination - which should take both
I suspect they are modular level - as iirc they are pre-fader - but there may be attentuation - not checked the BOM yet - the 6hp versions with 1/4" outputs appear to have some smd ICs (so maybe there is/maybe there isn't), but are also described as usable as standalone 1/8"->1/4" adapters - not that that means anything as signal path could very well be:
rear headers (-> attenuation) -> 1/8" -> 1/4"
most modern mixers/audio interfaces should be able to handle modular level signals - before I got the texmix I was using a cheap yamaha mixer (MG12? cost me about €100 new in the mid-2000s) - and it was fine - just turn the gain right down! or not
if you really want to know send Mangu an email (contact details are on website) - he usually responds pretty quickly
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities