An apparatus, according to one embodiment, includes a first circuit electrically coupled to a first read transducer and a first parallel circuit, the first read transducer having a tunnel valve structure having a resistance. A second circuit is electrically coupled to a second read transducer having a tunnel valve structure. An area of a tunnel barrier portion of the second read transducer along a plane of deposition thereof is larger than an area of a tunnel barrier portion of the first read transducer along a plane of deposition thereof.