Document revision 1.1 – Last modification : 27/06/11
Step
Description
5.
High voltage check
Set your DMM to DC Volts on a 500 V scale and connect it between TP2 (GND) and TP7
(V+). Use test hooks and be careful not to create shortcuts.
Plug in power and check that the 3 LEDs on the power supply unit are lighting normally. If
one or more LED is staying off or is lighting too low or too bright, immediately plug off
power and start checking your board.
Check that you get a positive voltage of 295 to 300 Volts on your DMM.
Plug off power.
Discharge capacitors.
6
Heater check
Insert both tubes in their respective sockets. Do that progressively, without hardness,
the risk being to bend one of the tube pins.
Set your DMM to DC Volts on a 3V scale and connect it between TP6 and TP5. Use test
hooks and be careful not to create shortcuts.
Plug in power.
The value displayed should ramp up from 0.2V to around 0.6V then back slowly to 0.56V
when the tubes get hot.
This value is the voltage across a 3.75 Ohms resistor, in serial connection with the heater
circuit. 0.56V means a current of 0.56 / 3.75 = 150mA in the filaments.
Plug off power.
Discharge capacitors.
7.
Sound check
Connect the input and output XLR wires to the board terminals.
Plug in a dynamic microphone to the input XLR.
Connect the output to your monitoring system. It can be a headphone amplifier or it can
go through one of your ADC inputs if you run a software studio.
Set gain switch to Mid, gain knob to minimum, Hi-Pass switch up, Air switch centre, phase
switch up, 48V up and Output level to max.
Plug in power and wait about 30 seconds for tubes warm up.
Turn up the gain knob until you hear the microphone. If the gain is not enough, switch to
High-Gain. Check that your micpre is working. Check the 3 switch gain positions, the High-
Pass switch, the Air switch, the phase switch and the output level knob.
Make the same test with a static microphone, with the 48V switch set to On.
Plug off power.
Set the 48V switch to Off.
Discharge capacitors.
8.
DI check
If you are using a SKMP version 1, plug the board's flat cable to connector CN1 or CN2
on the DI02 board if it is not the case yet.
Insert an instrument jack into the corresponding front panel jack socket.
Plug in power.
You should hear your instrument when playing.
Plug off power.
Copyright ©2008 SoundSkulptor
