Highland Dynamics BG2 Compressor

Highland Dynamics BG2 Compressor is an all-tube vari-mu compressor with a fully transformer-balanced signal path. The front end follows the British modifications of the Altec 436, while the output stage uses a pair of 6V6 tubes in the manner of the RCA BA6A and the Gates designs.

A vocal that no longer needs automation

A vari-mu circuit increases its reduction as level rises, so loud phrases are held down harder than quiet ones and the transitions stay smooth. Set correctly, a vocal track sits in the mix without drawing fader automation phrase by phrase. Two attack times are available, 30 ms and 110 ms, alongside six release times running from 270 ms to 2.8 seconds.

Three operating modes instead of three units

British mode delivers clean, smooth, high-fidelity compression. American mode passes more harmonic content and colours the signal noticeably. Line Amp mode disables compression entirely and leaves a driven tube amplifier, so the unit can be used purely for colour. The input switches between 600 and 150 ohms: the lower setting gives more gain and a stronger transformer contribution, enough to connect a microphone directly. A link switch pairs two units for stereo using ordinary instrument cables.

KEY FEATURES

• All-tube vari-mu compressor with automatic levelling
• Fully transformer-balanced signal path
• Front end in the style of a British-modified Altec 436
• Output stage built on a pair of 6V6 tubes
• British, American and Line Amp modes
• Switchable 600 or 150 ohm input impedance
• Stereo linking with a standard instrument cable
• Custom oversized transformers and a Simpson meter

TECHNICAL SPECIFICATIONS

• Type: all-tube vari-mu compressor
• Balancing: transformer coupled at input and output
• Output stage: two 6V6 tubes
• Attack time: 30 ms (Fast) or 110 ms (Slow)
• Release times: 270 ms, 400 ms, 700 ms, 1 s, 1.7 s, 2.8 s
• Input impedance: 600 ohm or 150 ohm, switchable
• Modes: British, American, Line Amp
• Feedback: switchable settings
• Stereo link: link switch, instrument cable
• Metering: US-made Simpson meter
• Components: custom transformers, US and European capacitors