Caffeyl-CoA reductase-Etf complex catalyzes the reduction of caffeyl-CoA to yield hydrocaffeyl-CoA. It couples the endergonic ferredoxin reduction with NADH as reductant to the exergonic reduction of caffeoyl-CoA with the same reductant. It uses the mechanism of electron bifurcation to overcome the steep energy barrier in ferredoxin reduction. The electron transfer flavoprotein (Etf) mediates the electron transfer between the different donors and acceptors. The iron-sulfur cluster may be involved in electron transport, possibly in the intramolecular electron transfer from the Etf protein subunit to the caffeyl-CoA reductase subunit inside the complex. The complex can also reduce 4-coumaroyl-CoA and feruloyl-CoA. hydrocaffeoyl-CoA + 2 NAD(+) + 2 reduced [2Fe-2S]-[ferredoxin] = (E)-caffeoyl-CoA + 2 NADH + 2 oxidized [2Fe-2S]-[ferredoxin] Binds 1 FAD per subunit. Binds 2 [4Fe-4S] cluster per subunit. Part of the homotrimeric caffeyl-CoA reductase-Etf complex composed of (R)-2-hydroxyisocaproyl-CoA dehydratase CarC, and the electron transfer flavoprotein (ETF) alpha (CarE) and beta (CarD) subunits. Belongs to the ETF alpha-subunit/FixB family.