Buzz Audio Essence True Class A 500 Optical Compressor

Buzz Audio Essence: True Class A optical compressor for 500 Series frames

The essence control circuit design is based on the Buzz Audio SOC-1.1 Stereo Optical Compressor but the main audio path utilises our BE40 and BE50 True Class A amplifiers along with high spec Lundahl input and output transformers. The input transformer is directly coupled to the Buzz proprietary Opto gain reduction element (completely passive input), amplified and then balanced via the output transformer - a very simple but gutsy signal path!

The essence control circuitry utilizes the Differential Drive Side Chain (DDSC) topology that was developed for the SOC-1.1. This system, which processes positive and negative audio waveform in seperate paths, provides the incredibly musical characteristic you will hear with this unit. The DDSC design also provides for a much faster attack time compared to most other LDR based optical compressors.

Simple side chain equalizers have been provided to allow the user to adjust the sensitivity of the compressor at high and low frequencies. In addition, a side chain insert point is provided for more complex EQ and compressor "keying".

The essence consumes 2 slots within a 500 Series rack. The input/output (I/O) connectors associated with the first slot carry the main audio path. The I/O connectors associated with the second slot are used for a side chain insert point (send and return). The insert can be switched in/out of circuit and monitored via front panel switches.

PLEASE NOTE - RACK COMPATIBILTY

Each Buzz Audio Essence module uses 2u rack spaces and draws 120mA +/- 15-18 volts DC, as supplied by rack power supply. Most currently manufactured rack systems will easily power a full compliment of essence units, but some older rack systems may have insuffcient power, if in doubt, please check with your rack manufacturer. We recommend the API Lunchbox and VPR500 racks.

Features:

• API 500VPR Series rack module format - plug in and play
• Advanced analogue technology - not a clone or copy of products from the past
• Powerful fully discrete hi-bias, wide bandwidth, differential Class A amplifiers
• Passive transformer coupled input, transformer coupled output
• Side chain insert point
• Side chain monitor selector
• On board side chain EQ
• Unique Differential Drive Side Chain design
• May be linked to multiple essence units within one rack
• Switchable 10 segment VU meter

NOTE: Due to some misinformation during the design of the potion and essence 500 series compressors, the card edge connection for the linking of our 500 Series compressors is incorrect.

The potion and essence have PIN 11 designated as the link connection, when in actual fact the API standard is PIN 6. This error can be easily remedied with a simple wire link soldered between PIN 6 and PIN 11 of the potion and/or essence edge connector. Click for details.