The Balance Box

The use of close tolerance (0.1%) components and a state of the art transformerless design enables the unit to operate with a wide variety of inputs, either balanced or unbalanced, with low noise and distortion, while operating from a single PP3 battery. Extended frequency response with low phase shift results in superior transient performance compared to transformers. The true floating nature of the circuit enables both input and output to be configured as balanced or unbalanced, in either the microphone or line modes at all gain settings, without change to the nominal stage gain selected. Comprehensive protection from radio frequency interference is provided by the balancing of the lines, low pass filtering and screening.

1. With long microphone cable runs, the Balance Box can be used, with either balanced or unbalanced microphones, and, with switchable gain in the range 20 dB to 50 dB in 10 dB steps, to provide a low impedance high level output for driving long balanced lines particularly advantageous in electrically noisy environments. Continuous gain adjustment is available to special order by replacing the gain selector switch with a potentiometer control.

2. With short microphone cable runs, the Balance Box can be used as a high quality balanced preamplifier driving an unbalanced input directly.

1. With such sources as CD, DAT, Cassette players and tuners, the Balance Box can be used as a line input device with a high bridging input impedance and gain selectable in the range -10 dB to +20 dB to convert an unbalanced output to a low impedance balanced line output. For stereo sources a balanced mono signal can be obtained by resistively summing the left and right outputs into the Balance Box input. For stereo two units are required.

2. Conversely, the Balance Box may be used to convert an unbalanced input on mixing desks, control centres, cassette and DAT recorders, etc. to a balanced input where this facility is not available or is of inadequate performance.