RCA 12AU7 - black plates

The 1957 RCA 12AU7 tubes in this precisely matched pair have long black plates and D getters. The white labels on the glass have the RCA logo and matching date codes. Both tubes test as new with balanced sections and low noise.

This rare 1952 military spec RCA JRC-12AU7 tube has long black plates and a D getter spot welded to one of the plate posts. The white label on the glass has the RCA logo and reads "JRC-12AU7." Tube tests as new with high gain and balanced sections.

This late 1950s 12AU7 was made by RCA and labeled for organ companies. (Tubes that were intended for use in organs were screened for low noise.) Tube tests good.