STA-LEVEL Description
Overview
The Retro Instruments STA-LEVEL is a replica of the legendary 1956 Gates STA-LEVEL. The STA-LEVEL dominated the sound of hit radio in the 1960’s. Now these super musical sounding compressors have found their way into today’s hits. The Retro Gold Edition celebrates fifty years of the products existence. Each Retro STA-LEVEL is point-to-point hand wired in the normal tradition. We wanted to fully capture the magic of the original sound. We think you’ll find it very useful in your studio.
The Scarce 6386 Tube
The STA-LEVEL uses the scarce and coveted 6386 tube in a classic G.E. circuit design. Scarcity is no longer a concern. The Gold Edition STA-LEVEL can use a pair of commonly available 6BJ6 tubes in place of a 6386! The choice is yours and the sound is undeniably true to the original.
The Original 6386 Circuit
The original 6386 compressor developed by G.E., The Unilevel, utilized a novel program controlled release circuit. Several manufacturers began creating compressors using this wonderful sounding 6386 design. Models were made by RCA, Collins, ITA, Metron, CBS Labs, CCA and Gates. The STA-LEVEL implementation creates density and consistency while minimizing typical compressor side-effects at up to 40dB of gain reduction! The program path is push-pull and transformer balanced to cancel control-induced distortion. A 6V6 output stage provides wide voltage swing allowing 40 dB compression and line output of up to +24 dBm. The result is that the STA-LEVEL brings a uniquely familiar intimacy, air and warmth to your tracks.
One Trick Pony?
Most all compressors and limiters bring out some noticable detail because of the nature of attack time on peak transients. Compression also pulls up softer sounds which creates useful density. The most critical aspect of a compressor is the musicality in which the gain is changed over time. The STA-LEVEL original attack and release times are very well chosen to minimize the audibility of pumping and distortion while adding the desired density and consistency. The release time is also dependent on the 6386 transconductance so it becomes a non-linear function, releasing faster at higher gain reduction amounts. In dual mode, another constant is added that further creates density and masks the sound of the slower constant acting as AGC or “gain-rider”.
The STA-LEVEL adds a pleasing transient distortion manifested as subsonic punch. This subsonic energy is created at gain reduction attack periods and accentuates the natural attack waveform of the audio material. It is referred to as VCA thump by circuit designers and occurs from imbalances in the VCA response to control bias. It is a very characteristic sound of real tube compressors that make them so useful. Subsonic energy present in a live instrument or performance are easily lost in the recording process. The STA-LEVEL brings back the live realism. Furthermore, your recording processes down the line will have new usefulness and meaning. Real vacuum tube compression is the one trick pony you will applaud again and again.
Revisions
Revisions to the original design include: Tube balance can be instantly aligned on-the-fly without test equipment; Uses 6386 tube or a pair of 6BJ6 tubes; Two or more STA-LEVELs can be coupled together for stereo, surround or sidechain operation; XLR transformer balanced input and output; IEC Power Connector; Hand matched audiophile-grade coupling capacitors; High quality, custom wound transformers used throughout; top AND bottom plates; Internal component safety cover.