Teletronix LA-2A Mono Tube Opto Compressor/Limiter - Revision 1 Gray Face #313 (Vintage)

The Teletronix LA-2A Leveling Amplifier has a long history stretching back over half a century. During that time the company changed hands and the model went through a variety of incarnations. Despite these several changes, the LA-2A has remained one of the most popular tools in the recording studio, beloved by engineers for its program-dependent compression and ease of use. Beautiful for vocals, bass, guitars, overheads, drums, etc. 

Essentially there are six different versions of the LA-2A, based on various design elements, parts, outward appearance, and parent companies. The six revisions can best be classified as: Revision 1 (the original); Revisions 2A, 2B and 2C (all inter-related in various ways); Reissue 1 and Reissue 2. The first four versions kept consecutive serial numbers, while the two reissues had their own numbering scheme.

The final, seventh version, appeared when Universal Audio was resurrected by Bill Putnam Jr., and the LA-2A made its modern reappearance in the line of "UA Classics".

Briefly the differences are most easily classified by company ownership:

1. Revision 1 - the original, produced in 1962 by Teletronix under Jim Lawrence, inventor of the LA-2A.
2. Revision 2A - Teletronix patent is acquired by Babcock Electronics
3. Revision 2B - Teletronix patent is licensed from Babcock Electronics by Bill Putnam Sr. / Studio Electronics
4. Revision 2C - Teletronix patent is acquired from Babcock Electronics by Bill Putnam Sr. / UREI
5. Reissue 1 - late 70s reissue by UREI / United Recording Electronics Industries
6. Reissue 2 - late 80s reissue after UREI is acquired by Harman Electronics / JBL

This unit is an original gray face version, dubbed Revision 1, with the following features:

• Serial numbers 001-600 (approx.)
• Faceplate is painted grey, with red "Teletronix Engineering" logo
• Produced by Teletronix in Pasadena, CA (sometimes labeled Los Angeles, sometimes labeled Sunnyvale)
• Type / Serial No. on a separate metal plate
• All rear panel graphics are hand stenciled or stamped
• Octal jumper socket located before the UTC HA-100X input transformer for pad/pre-emphasis modules
• Later units included a variable pre-emphasis filter, R37
• First compressor to use photo resistors and luminescent panels to achieve gain reduction - the T4A

Click here to learn more about the history of the Teletronix LA-2A.