In his Positive Feedback review of the EAR-Yoshino 868L line stage pre, the reviewer made the statement that, though the 868 provides XLR jacks for balanced operation, the pre-amp circuitry itself is single-ended. Designer Tim deParavicini in his manufacturer reply corrected the reviewer, stating that no, the 868 is a true balanced design. It is a commonly-held understanding by audiophiles and semi-pro hi-fi reviewers that a true balanced amp by definition has doubled parts. As atmasphere just said, that is a misconception and misunderstanding of what balanced is. A pre-amp can have single-ended circuits yet be true balanced in operation.
The real concern in any piece of gear is how the balanced inputs/outputs are implemented. In the EAR 868, Paravicini accomplished that goal via transformers. In his Music Reference RM-200, Roger Modjeski does so with a resistor network. Companies with lower standards typically create balanced inputs/outputs with the dreaded opamp, and with the expected sonic compromise. A higher retail price does not necessarily buy one balanced ins and outs NOT created with opamps. If possible, inspect the schematic of any piece of balanced gear you are considering buying, to see how it’s balanced connections are created, and if they conform to AES48.