Manual

The Technical Stuff
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At least one 610 module is still in use at Ocean Way Studios, site of the original United Recording
facility. Allen Sides, who purchased the studio from Putnam, personally traveled to Hawaii to collect
the 610 console that was used to record the live “Hawaii Calls” broadcasts. Celebrated engineer Jack
Joseph Puig has long been ensconced in Studio A at Ocean Way with the 610 (and a stunning
collection of vintage gear) where he has applied the vintage touch to many of today’s artists,
including Beck, Hole, Counting Crows, Goo Goo Dolls, No Doubt, Green Day and Jellyfish.
Today’s LA-610 preamp section bears a lot of similarity to the original 610 module. Hand-selected
tubes are used, and the identical component values have been maintained, along with many of the
original unit’s features. Modern updates include a higher-quality power supply, polypropylene caps,
metal film resistors, custom-wound I/O transformers with double-sized alloy cores, and newly added
features such as high-impedance inputs, an enhanced EQ section, and phantom power, switchable
polarity inversion, and a switchable -15 dB pad on the mic input. In addition, the preamp section has
been “voiced” with a slight high-frequency boost to compensate for the warm nature of the optical
compressor it is paired with.
Compressor section
The compressor section of the LA-610 is based upon the LA-2A, a vintage tube device still revered by
audio professionals everywhere. The original design was the brainchild of James F. Lawrence Jr., who
had been a radar operator in World War II. Following his tour of duty, Lawrence began studying
electrical engineering at the University of Southern California, while also quietly designing sub-
miniature telemetry devices and optical sensors for the military. But his passion was always radio,
and he eventually landed a job as a broadcast engineer at KMGM in Los Angeles, where he soon
became frustrated with having to constantly ride gain to ensure a proper signal. This led to
Lawrence’s conception of a device he called a “leveling amplifier.”
Shortly afterwards, Lawrence started a company called Teletronix, setting up shop in his hometown of
Pasadena, California in 1958. Among the line of broadcast products manufactured by Teletronix were
conversion and transmitter tubes, emergency tone generators, multiplex generators, even full-scale
radio transmitters. Lawrence’s first attempt at building a leveling amplifier resulted in the Teletronix
LA-1, of which around one hundred units were made.
Teletronix LA-1