Sampling Modulator Assembly manual
( para PCB V1.5)
Main PCB:
(The smaller one)
Open “Main Board Bag A”
Resistors:
QTY.
12
1
1
2
2
1
1
2
2
7
3
Value
10k
100k
20k
4k7
47k
1K
2k2
6K2
12k
470k
330K
Code
Brown, black, black, red, brown
Brown, black, black, orange, brown
Red, black, black, red, brown
Yellow, violet, black, brown, brown
Yellow, violet, black, red, brown
Brown, black, black, brown, brown
Red, red, black, brown, brown
Blue, red, black, brown, brown
Brown, Red, black, red, brown
Yellow, violet, black, orange, brown
Orange, orange, black, orange, brown
Name on PCB
R5, R9, R10, R11, R14, R18, R25,
R26, R28, R32, R34, R38,
R7, R15, R23, R31, R33, R35, R36
R13, R17, R29
R24, R30
R27, R37
R2, R21
R19, R20
R8
R4
R16
R22
1
1
1
2k7
820 Ohm
2k
Red, violet, black, brown, brown
Gray, red, black, black, brown
Red, black, black, brown, brown
R3
R39
R40
1 390 Ohm Orange, white, black, black, brown R12
Solder diodes respecting the polarity. Line on the diode must match the line on the PCB's silkscreen. D2 comes presoldered to fix a small PCB bug.
QTY.
2
1
Value
1N5817
1N4148
Code
1N5817
1N4148
Name on PCB
(black color) D22, D23
D1 , D2 (presoldered)
QTY.
7
3
2
1
1
1
Solder the two ferrite beads (FERRITE+, FERRITE-) passing trough a resistor leg.
Solder them same way as resistors.
Open the “Main board Bag B”
Place the sockets on IC1, IC2, IC3, IC4, IC5, Taking care of the polarity (The mark on the front of the socket, must match the one on PCB's silkscreen) then solder them.
Solder capacitors:
Value
100n
2n2
10µF
10n
1n
47p
Code
104
222 (silver color)
10µF
103
102
470
Name on PCB
C1, C4, C7, C9, C11, C15, C16
C6, C8, C12
C13, C14 (Mind polarity! Long=+ Short=-)
C2
C5
C10
1 100p 101 C3
Solder transistors . Be sure they are on right position (same as the silkscreen on the PCB)
QTY.
Value Code Name on PCB
6 2n3904 3904 Q1, Q2, Q3, Q4, Q5, T1
Solder the trimmer (A small plastic-square-thingie with tree legs) at (“V/Oct”).
Place the ICs on the sockets taking care of the polarity. The mark on the front of the IC must match the one on the socket.
QTY.
3
1
1
Value
TL072 or TL082
LM393
LF398
Name on PCB
IC1, IC2, IC3
IC4
IC5
Solder the “Power” connector from the bottom of the PCB taking care of polarity.
Place the two Male Pin Headers (CON1, CON_2)at the the silkscreen side, then solder them making sure it is 90º from PCB.
CONTROL PCB:
(the bigger one)
Open “Control Board bag A”
QTY.
8
3
2
1
1
1
Solder the resistors:
Value
18k
100K
3k9
1M
180k
1K
Code
Brown, gray, black, red, brown
Brown, black, black, orange, brown
Orange, white, black, brown, brown
Brown, black, black, yellow, brown
Brown, gray, black, orange, brown
Brown, black, black, brown, brown
Name on PCB
R103, R104, R105, R106, R107, R108,
R109, R111
R100, R114, R115
R102, R110
R112
R113
R101
Solder diodes minding polarity (Black line has to match the white one in the board's silkscreen):
QTY.
1
Value
1N4148
Solder the capacitors:
Code
1n4148
Name on PCB
D100
QTY.
1
Value
100n
Code
104
Name on PCB
C100
Open “Control Board Bag B”
Place and solder the two female pin headers ensuring it is 90 degree from the PCB
(To_conn_1, To_conn_2).
Screw the metallic spacer from the bottom of the control PCB (by the male side) using the nut.
Place the two position toggle switch on (SW1)
but don't solder
it until the front panel is on place and with all nuts screwed to it.
This way it's easier to solder them on the right position and height. Keep in mind that the front panel holes are quite narrow and is almost impossible to place it with all the components already soldered..
Ensure it's the two position switch! You will recognize it because is the one when switching it have just two different positions and never stops on the middle.
Place the 8 tree position toggle switches on SW2, SW3, SW4, SW5, SW6, SW7, SW8,
SW9. But also
but don't solder
them until the front panel is on place and with all nuts screwed to it.
Open the bag with the jack sockets.
Place jack sockets ensuring they are by the silkscreen side but (again)...
don't solder
them until the front panel is on place and with all nuts screwed to it.
Caution: the switch nuts and the jack nuts looks the same but they are not, and wil not fit in each other's thread so dont mix them!
Put the 8 LEDs (control board Bag A)on place (D2, D3, D4, D5, D6, D7, D8, D9) taking care of the polarity but.........again....
don't solder them
until you put the panel on place because that way it's easier to place them at the correct height.
Important: Long leg is the positive one and must match the “+” symbol on the PCB
Cut the little ledge on all three pots with cutting pliers as pictured:
Place the Pots (RATE, RATE_FINE ) but as with the LEDs etc, don't solder them yet until they are totally screwed to the panel, (sorry but this is the only method to have all the panel components on the right height).
Put the panel on place gently moving all components until it fits perfectly.
Screw the nuts totally to the jacks, switches and potentiometers and...
Finally!!
solder them.
Place the LEDs at the exact height (thru their panel holes) and solder them.
Plug Main PCB to the Control PCB with the pin headers and screw them with one of the 3mm screws.
Place the two knobs on the potentiometers and the plastic covers on the switches.
Congratulations!! your Sampling modulator is almost finished, but before you ca use it...
Adjustment procedure:
Most of the features of the sampling modulator work straight away, but in order to have a correct V/oct tracking you should adjust the “V/oct trimmer” carefully.
For that you will need:
-A decent multimeter.
-A small plane screw driver or even better a trimming tool.
-A Tuner.
-A calibrated voltage source. You can do one with a multi-turn potentiometer connecting it as voltage divider as follows:
Connect Leg 1 to positive, leg 3 to negative and use leg two as you voltage source out. IMPORTANT : Always measure your voltages when they are connected to the CV IN.
The tune process is a iteration of successive approximations as follows:
Connect a turner to the clock out or to Pin 1 of IC3
1 -Move the tune and fine tune pots until you have an E2.
2 -Add 3.000 Volts to the CV IN with the voltage source. Measure this voltage when is already plug to ensure it is 3,000 (3 volts)
3 -Adjust TUNE until E5 +0 cents
4 -Unplug the voltage source from the CV In and adjust V/Oct trimmer until reach
E2 + 0 cents
5 -Back to step number 2..4 until there is no need of adjustment after adding the
3.000 volts.
You can also use a decent MIDI to CV interface or any device that can send pitch cv accurately as voltage source. Just move within three octaves to make sure it's tracking properly (instead of using voltages)
Done!
Enjoy your sampling modulator!
You can fix it to your rack with M3 screws provided.
