Tube Tech MEC 1A Recording Channel - Manual

Lydkraft ApS
Mose Allé 20, DK2610 Rødovre
Denmark
1
(980112)
TUBE-TECH MEC 1A
Recording channel
Description:
The TUBE-TECH recording channel MEC 1A is a combined microphone and DI
preamplifier, equalizer and optical compressor intended for recording directly to any
recording media.
Microphone preamp:
The microphone preamplifier consists of a microphone input transformer (with a static
screen) with a step-up of +10 dB, two dual tube preamplifiers with two stepped gain
switches, one with 10dB/step (coarse) and one 1dB/step (fine) giving a total gain range of
+20dB to +70dB.
The microphone input is provided with a switchable -20dB attenuation (PAD), switchable
+48 V phantom-power and phase reverse.
A highpass filter for the microphone and the DI input is switchable between off, 20 Hz and
40 Hz.
The microphone input is capable of accepting levels of up to +6 dBU (1.55V) at 40 Hz
without the PAD. With the PAD switched into the circuit, the MEC 1A can be used as a
unity gain line amplifier accepting levels up to +26 dBU (15.5V) at 40 Hz.
The high impedance DI input is unbalanced and placed in the circuit directly after the input
transformer. The gain range for this input is +10dB to +60dB. When in use, the microphone
input is disabled.
Equalizer:
The equalizer has low and high shelving filter with a gain range of +/- 15dB, each with 6
switchable frequencies and a band filter with a gain range of +/- 20dB, 12 switchable
frequencies and a bandwidth control.
The shelving and the bell filters are designed around a dual tube operational amplifier.
The equalizer has a separate in /out switch.
Compressor:
The compressor is of the optical device type. It has controls for ratio, threshold, attack and
release. A switch selects between manual attack and release and fixed attack and release.
With the link switch it is possible to link several units together on two independent bi-
directional buses. The compressor has a separate in /out switch.
In normal operation the equalizer is in front of the compressor, but a switch enables the
compressor to be in front of the equalizer.
COMPRESSOR INTERCONNECTION:
The side chain sockets for interconnection of several compressors are located on the rear
panel.
A switch (link1/link2) on the front selects which compressors are interconnected, and on
which bus they are connected.