Universal Audio LA-610 Mic PreAmp

An original Universal Audio LA-610 (not the mkII) that is in excellent physical and working condition.  Since this unit is no longer in production, I stole the following info from an online copy of the owner's manual.

This unit combines a modified channel of our 2-610 Mic Pre with an LA2A style T4 Optical Compressor. Our 610 was inspired by the microphone preamp section of the 610 tube console designed by my father, M.T. “Bill” Putnam, in the 1950s. The 610 was a rotary-control console and was the first console of the modular design. Although technologically simple compared to modern consoles, the 610 possessed a warmth and character that kept it in demand for decades. As a prominent part of my father’s United/Western studios, the 610 was used on many classic recordings by Frank Sinatra and Sarah Vaughan. The Beach Boys Pet Sounds, the Doors LA Woman, and Van Halen’s debut album were all recorded on the 610. The legendary Wally Heider used the 610 in his remote truck for many of his best known live recordings. At Ocean Way Studios (formerly United), the 610 is lovingly preserved and still used in Studio B.

The T4 Compressor element in the LA-610 is identical to the circuit components housed inside the T4 optical cell used on the legendary LA-2A compressor. The heart and soul of the LA-2A is mostly a result of this special optical gain control element. The unique and musical behavior of the LA-2A is present in the LA-610 as well, the main difference being a more colored sonic signature with the LA-610. Unlike the LA-2A, the LA-610 offers a wide variety of tone and character by virtue of the dual stage level controls and EQ section. The incredible price/value of the LA-610 is the result of using the existing 610 tube amplifier and simply adding the T4 optical element creating a mono channel strip that can serve as a mic or Instrument preamp with or without EQ and compression. In addition, the LA-610 has a line level input for use as a dedicate compressor with or without EQ and tube saturation.

LA-610 Specifications

• Microphone Input Impedance Selectable, 500ohm or 2k ohm Balanced Line Input Impedance 20k ohm
• Hi-Z Input Impedance Selectable, 2.2M ohm or 47k ohm Maximum Microphone Input Level -8 dBu (2K input Imp. & 15 dB Pad in)
• Maximum Output Level +20 dBu (120Vac line) 
• Internal Output Impedance 80 ohm
• Recommended Minimum Load 600 ohm
• Frequency Response 20 Hz to 20 kHz +/- 0.5dB Maximum Gain 40 dB (Line), +77dB (Mic) 
• Noise Floor -72 dBu 20 – 20kHz (Line In, Unity Gain) Tube Complement (3)12AX7, (1)12AT7A, (1)6AQ5 
• Power Requirements: 115V / 230V operation Dimensions: 3.5” vertical, 19” rack (2RU). 
• Weight: 12 lbs.