The LA2A Compressor is a tube levelling amplifier with an optical gain control unit.
       
     
This optical gain control unit was built in a salvaged relay enclosure that plugs into a octal socket. The illumination is a EL panel, like the originals, with light dependent resistors (LDR) to attenuate the signal. The LDR simply operates in a vol
       
     
This build uses Jensen line level (1:1) input transformers, to operate as a line level device, instead of the 10:1 transformers found in the originals.
       
     
The circuit board is from [silent-arts] (on groupdiy). The output transformers are EDCOR WSM 15k:600
       
     
RCA 6AQ5 power tubes drive the EL panel.
       
     
This beautiful front panel came from don-audio. I put a switch for a sidechain HPF on the front panel, with a frequency select knob on the back panel.
       
     
The LA2A Compressor is a tube levelling amplifier with an optical gain control unit.
       
     
+

The LA2A Compressor is a tube levelling amplifier with an optical gain control unit.

This optical gain control unit was built in a salvaged relay enclosure that plugs into a octal socket. The illumination is a EL panel, like the originals, with light dependent resistors (LDR) to attenuate the signal. The LDR simply operates in a vol
       
     
+

This optical gain control unit was built in a salvaged relay enclosure that plugs into a octal socket. The illumination is a EL panel, like the originals, with light dependent resistors (LDR) to attenuate the signal. The LDR simply operates in a voltage divider, followed by make-up gain.

This build uses Jensen line level (1:1) input transformers, to operate as a line level device, instead of the 10:1 transformers found in the originals.
       
     
+

This build uses Jensen line level (1:1) input transformers, to operate as a line level device, instead of the 10:1 transformers found in the originals.

The circuit board is from [silent-arts] (on groupdiy). The output transformers are EDCOR WSM 15k:600
       
     
+

The circuit board is from [silent-arts] (on groupdiy). The output transformers are EDCOR WSM 15k:600

RCA 6AQ5 power tubes drive the EL panel.
       
     
+

RCA 6AQ5 power tubes drive the EL panel.

This beautiful front panel came from don-audio. I put a switch for a sidechain HPF on the front panel, with a frequency select knob on the back panel.
       
     
+

This beautiful front panel came from don-audio. I put a switch for a sidechain HPF on the front panel, with a frequency select knob on the back panel.