Front end circuits and associated apparatus, systems, and methods for use in electronic devices such as buried utility locators are disclosed. The circuits include receivers and filters on input signals that are coupled to ground rather than differentially. A multiplexing circuit allows shared use of amplifiers, and analog-to-digital converters via a switching mechanism for selectively making or breaking electrical connection to the receiver channels for efficient sharing of electronics resources while minimizing crosstalk interference and advantageously reducing costs.