Tube Tech LCA 2B Dual Channel Tube VCA Compressor - Manual (Page 4)

LYDKRAFT ApS
Mose Allé 20, DK-2610 Rødovre
Denmark
4
ADJUSTMENT PROCEDURE:
CAUTION:
Before making any adjustment let the unit heat-up at least 30 min.
Always check the DC voltages at the power supply.
When the VCA tube has been replaced, adjustment of:
BASIC GAIN
GAIN REDUCTION
BALANCE
shall be carried out.
The adjustment procedure refers to channel 1. The trim pots in brackets are for
channel 2.
At the sidechain jack sockets at the rear of the unit, the tip is link 1 and the
ring is link 2.
ADJUSTMENT OF BASIC GAIN:
1) Turn the THRESHOLD-control for the compressor and limiter fully
counter-clockwise.
2) Apply a signal of 1 kHz, 0,0dBU to the input of the compressor.
3) Turn the GAIN-control fully clockwise (+10).
4) Adjust the preset GAIN P3 (P103) (located on amp/psu PCB) to an out-
put-reading of +10,0dBU.
ADJUSTMENT OF GAINREDUCTION:
1) Turn the THRESHOLD-control for the compressor and limiter fully
counter-clockwise.
2) Apply a signal of 0,0dBU, 1 kHz to the input of the compressor.
3) Adjust the GAIN-control to an output-reading of 0,0dBU.
4) Apply a DC-voltage of +5,000 V into the sidechain jack socket (tip).
5) Set the LINK-switch at LINK 1 and observe that the output level has dropped to
-20,0dBU. If this is not the case, adjust the level with P7 (P107) at the
sidechain PCB, to obtain a drop of -20,0dB.
The level might increase a little (+0.5 to +1dB) from the instantaneously value
(within 5-10 sec.). This is quite normal.
(940530)