TL Audio 5050 - Single Channel Tube Microphone Preamp with Fully Variable Compressor

Inputs

Three input sources include a balanced microphone via an XLR connector, balanced line input via a TRS jack socket and an instrument jack socket located on the front panel, where it provides a convenient means of patching a guitar or keyboard directly into the processor.

The input stage is a hybrid valve circuit, containing one stage of an ECC83/12AX7A dual triode valve, run from a 150V DC stabilized supply.

The input gain is governed by a centre-detented control, calibrated for 0dB nominal gain from the line input sources at the centre and providing up to 60dB of microphone gain. The instrument input is also controlled by the input gain potentiometer, and will accept a wide range of sources from passive pickups through to active guitars and keyboards.

Phantom power and a 30dB pad are provided on the microphone preamp stage and a switchable 90Hz high pass filter is active on all three inputs.

Output

Balanced 1/4' TRS socket at a nominal level of +4dBu.

Metering of the output is by an eight-segment LED bargraph.

Compressor

Offers variable control of threshold and ratio, with switchable attack and release times and a choice of soft or hard knee compression modes.

An independent gain make-up control is provided, to retain the subjective loudness of a compressed signal, plus an overall master output level control.

The output control has a nominal 0dB of gain at its centre, with up to 15dB of further gain available to achieve the high level required for some digital recorders.