The Summit Audio Tube Leveling Amplifier is a hybrid of technologies.
It contains both vacuum tube and solid state components. This combination of old and new technologies produces an incredibly warm and smooth sounding compression device without the inherent disadvantages of the older designs.
The TLA-100A features a vacuum tube amplifier driving an electronically balanced 990 output stage. All the signal amplification in the audio path takes place in the tube circuit. The 990 amplifiers provide a low output impedance for driving cables and 600 Ω loads. The 990 is a high performance op amp made of discrete parts, and then potted for thermal stability. The input is electronically balanced, and directly feeds the unique compression cell. The sidechain allows for stereo coupling, or the insertion of an equalizer.
Due to the combination of tube and solid state circuitry long term drift of the compression circuit is minimal and tracking of two TLA-100As stereo linked is within .3dB.
