Assembling the Analog Filter Board

Let's grab our second PCB. For this kit we included the standard SMR4MKII filter board. Unlike the control board this board is single sided. Make sure you are placing all components on the side with the screen prints.

Step one

Let’s start by placing some capacitors. For this step you will need…

•Ceramic Capacitors 100n for C5, C7, C8, C9, C14, C16, C17, C18, C23, C24, C26, C28, C29

•Ceramic Capacitors 10p for C3

Step two

Let’s place the protection diode at D1. This part is polarized! Make sure the stripe matches the markings from on the screen print. For this step you will need…

•Diode 1N 4001

Step three

Let’s place some electrolytic capacitors. Please note unlike the ceramic capacitors, these are polarized. Just like with LEDs, your longer lead is your (+) end. For this step you will need…

•Electrolytic Capacitor 220u for C20 and C30

•Electrolytic Capacitor 100u for C2, C11 and C12

Step four

Let’s now place the voltage regulators (LM7905 and LM7805) and the DC connector. The voltage regulators have VERY similar part numbers and orientation is important so please be extra careful when placing these. For this step you will need…

•DC connector from bag labeled “Audio MIDI Power”

•IC LM7805 +5V Vreg for IC9

•IC LM7905 -5V Vreg for IC5

If you’d like to add an on / off switch to the synth you can do so by placing one in the area next to the DC connector labeled SW. If you don’t plan to use this, bridge these connections with a small piece of wire (you can use trimmed leads from other parts). The included acrylic case does not have space for an on/off switch.

Step five

Back to resistors. Grab the following…

•Resistor 68 - this is the top left most resistor on this board, it is labeled “68” and can be found directly to the right of C5 and below J2

•Resistor 220 for all places labeled “220,” you will need x6 of them

Step six

For this step you will need…

•Resistor 2.2k

•Resistor 1k

Step seven

Now add all of your 10K resistors. BE CAREFUL to not place these in any of the spots meant for 18k resistors as the text on the board can appear similar when not paying close attention.

Step eight

THE END OF RESISTORS. Take the rest of your resistors. Take your time, be careful placing all of them. This should include the following…

  1. 3x Resistor 18k 
  2. 1x Resistor 33k 
  3. 1x Resistor 47k
  4. 1x Resistor 100k
  5. 1x Resistor 150k
  6. 1x Resistor 330k

Step nine

Final ceramic caps. For this step grab…

•Ceramic Capacitor 100p

•Ceramic Capacitor 220n

Step ten

Solder in the rest of the sockets - be mindful to line up the notch with the notch on the screen print. The remaining sockets are include…

•Socket 14 pin x2

•Socket 8 pin x2

•Socket 16 pin x2

Step eleven

Let’s place our transistors - these are polarized so be mindful of their orientation. You’ll notice one side of these is flat and one is round, the silk screen on the board will match this to help you orient correctly. Grab…

•Transistor 2N3906 for Q1, Q2, Q3 and Q4

Step twelve

Let’s place the film capacitors. Grab…

•Film Capacitor 1n for C25, C27, C32, C34

Step thirteen

Let’s place the final electrolytic capacitors - remember these are polarized - the long lead is your (+). Grab…

•Electrolytic Capacitor 4.7u for C4, C21 and C22

Step fourteen

Place the 20k trimpot in the “V/Oct 20k” spot with the screw facing outward to match the screen print on the board. Grab…

•Trim pot 20k

Step fifteen

Let’s place the audio jacks and the pole selection header. We recommend placing the jumper on 4-pole mode to get the most out of this filter. Grab…

•Audio jacks from bag labeled “Audio MIDI Power,” for J2 and J3

•3 pin header from bag labeled “Headers,” to place in the Poles section

•2 pin jumper from bag labeled “Headers,”

Step sixteen

Using the acrylic case included with this kit there will not be much room to add gain pots for volume in and volume out (though it is possible using the additional side panel with holes included with the kit). If you do not plan to add gain pots bridge the bottom pad of each jack to the middle pot using some scrap trimmed leads as pictured below.

Step seventeen

Let’s slot the rest of our ICs! Grab…

•IC LM13700 dual OTA for IC3 and IC6

•IC Tl072 dual op-amp for IC2 (dot on the chip should be closest to the notch on the socket!)

•IC LT1054 DC/DC converter for IC1 (dot on the chip should be closest to the notch on the socket!)

•IC TL074 quad op-amp for IC4 and IC7

Step eighteen

Grab the 8-pin stacking headers from the bag labeled “headers,”  and solder one on to J4. Keep this as straight as possible as this is how the filter board connects to the control board. Plug the second one on top of this one.

Step nineteen

Congrats! You’ve built the Datadealer. Before placing this synth in to the included acrylic casing let's run some tests.

This guide was first published on Oct 12, 2016. It was last updated on Oct 12, 2016. This page (Assembling the Analog Filter Board) was last updated on Nov 11, 2019.