Adjustment procedure – Tube Tech MEC 1A Recording Channel User Manual
Page 5

Lydkraft ApS
Mose Allé 20, DK2610 Rødovre
Denmark
5
ADJUSTMENT PROCEDURE:
(980810)
CAUTION:
Before making any adjustment let the unit heat-up at least 30 min.
Always check the DC voltages at the power supply.
ADJUSTMENT OF PSU:
1) The DC voltage in TP202 shall be +240V.
Adjust with P201.
2) The DC voltage in TP203 shall be +150,0V.
Adjust with P202.
3) The DC voltage in TP204 shall be -150,0V.
Adjust with P203.
ADJUSTMENT OFFSET IN TUBE-OP-AMPS:
1) The DC voltage in TP1 shall be < +/-50mV.
Adjust with P1.
THE GRE SHALL BE MARKED BETWEEN 1.005-1.175
ADJUSTMENT OF BASIC GAIN:
1) Set the
“PAD”on “of
f
”.
2) Set the
“Low
cut
”on “of
f
”.
3) Set the gain control
“Coar
se”on "20".
4) Set the gain control
“Fi
ne”on "0".
5)
Tur
n
al
l
“
Gai
n”controls on the EQ fully CCW and the in/out switch on "Out
”.
6) Turn the
“Thr
eshol
d”fully CCW and the “Comp”in/out switch on "Out".
7) Turn the
“Out
put
gai
n”fully CW.
8) Apply a signal of 1 kHz, -20,0 dBU to the mike input.
9)
Adj
ust
t
he
pr
eset
“
Gai
n”P2 (on amp/psu PCB) to an output reading of +10,0 dBU.