XMIX offers 4 mixers and 2 attenuators in a 1U package, ideal for small systems but also useful for larger systems where users are wanting attenuators, and to to combine CVs etc.
One 3 channel mixer has level controls, the others are passive mixers but two of the mixers can combine up to 8 signals (some with attenuation).
Tangible Waves XMIX
Tangible Waves Tangible AE Modular XMix