AstroNoise (Atari Junk) Assembly Instructions


Welcome to the Atari Junk Console Assembly Instructions.   Hopefully, you have received your kit in the mail and are ready to build your circuit.  Let’s get started!

Attention, If you want to make this into a eurorack kit, please go to the Mod Instructions to make the trace cut, then follow the assembly options until you get done with all board mounted components.

Also make sure to keep a few resistor leads, because you will need to make a jumper for the eurorack mod power switch.

BOM Layout


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The first step in any successful electronics project is to make sure that you have all of the parts necessary to complete the circuit.

Check your kit against the BOM.  If you are missing a part, we’ll send it to you free of charge.


Attention: Changes may occur after the Assembly Instructions are created and the photos may not reflect those changes. Always use the BOM to verify the placement of components.


There is a modification needed on PCBs sold prior to June 2013.

If you bought your Atari Junk/AstroNoise after Jun 2013, go straight to the “On Board Components” section below.


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The OG Atari Junk PCB has a few issues that will have to be solved with jumper wires.

First we will need to cut the bad traces. Look closely at the picture above for more information.

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Now solder a jumper wire across the points on the trace where the surface has been exposed. Look closely at the picture! This is a very important step. It helps to put a little solder on the exposed areas before setting the wire. Remember to leave room for the other components. The other jumper is a little easier. It jumps the solder terminal inside D1 to the solder terminal labeled C (connect).

On-Board Components

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First solder all of the IC sockets to the board.

Make sure the little notch on top off the socket matches the lines on the circuit board.

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 Locate the component identifiers for R1 – R9.  Insert the resistors and solder all components onto the PCB.

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 Our next step will be to add all of the capacitors to our circuit.  C6 – C10 identify the placement of the ceramic capacitors.

C1, C2, C3, C5, C11, C12, C13 identify the placement of the electrolytic capacitors.

The longer lead on the electrolytic capacitors is positive. Make sure to match it up with the plus sign on the PCB.

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The black band on the schottky diode represents the negative lead.

Match up the black band with the white stripe on the board.

Insert the transistor with the flat side facing the flat white line on the board.

Wired Components

If you want to make this project into a Eurorack project, please follow the Mod Instructions, and not these instructions.

The next major step in our project assembly will be the wired components.  Attach wires to all of the potentiometers, switches, and jacks beforehand.  This will save time and the construction of the circuit will be much simpler.

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When you insert the LED align the flat (negative) side with the flat white line on the board. You can also mount the LED straight to the board, or leave it out entirely (no jumper wire needed).

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Insert the pots exactly as they are shown in the picture. (Please note: they won’t fit side-by-side if soldered straight to the board.)

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When installing the pot, some pots come with nubs near the shaft that may get in the way of installing the circuit into a case. Check for a nub and clip as necessary. Also wire in the audio/cv jacks as shown.  PLEASE NOTE: The CV input jack is a switched MONO jack.  Your circuit will not function properly if you do not use the proper jack.  When a CV source is plugged into this jack, only the volume and rate pots will function, the other 3 will not (this is proper).

Cut the pot nubs

Don’t forget to cut the nubs on the potentiometers as necessary.

Now wire up the mono jacks as shown. Take care to wire shunted mono jacks for both OSC_IN and CV_IN – otherwise your circuit will not function properly.


Mono Switched Jack

Mono Switched Jack

When wiring the CV Input jack or the OSC_IN jack, follow the diagram above to wire the Tip, Switch, and Sleeve contacts properly to the board. The output jack only uses the T and S contacts.

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Wire the switches as shown. There are two SPST switches and one SPDT switch.

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To supply our circuit with power, our next step is to attach the 9V battery jack and the DC jack.  The red wire from 9V battery jack goes to the square hole labeled ‘+’ and the black wire goes to the circular hole labeled ‘-‘.

Put the wires through the extra holes before they are soldered to the board. This will add extra stability and relieve tension on the power jacks.

Use this picture to wire up the DC jack in the correct location. P=pin S=Sleeve C=Connect

DC Jack Pinout

DC Jack Pinout

If you do not want to install the 9V DC jack and only install the 9V battery clip you will have to short the S and C pins for the 9V DC Jack like shown in the picture below*.

* Your PCB may not look exactly like the photo, that is ok. What is important is that you short the S and C pins together as shown in the photo.

No DC Jack

Short these contacts to get the circuit to work without the 9V DC Jack

Almost Done!

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Place the IC chips into the circuit. Bend the pins on the chips inward slightly to fit the socket.

Match the half-moon notches on the chips with the notches on the IC sockets.

Congratulations, your Atari Junk Console is complete!  Plug in a 9V battery and connect your circuit to an amplifier to see if your circuit is operational.  If not, go back through the steps in these instructions and look for any mistakes.

Eurorack Mod Instructions

Here are the extra parts needed to make a Euro AstroNoise:

1 x Resistor Clipping

10HP DIY Blank Panel (which will need to be drilled, see diagram below)

10-Pin Shrouded Header

3.5mm Right Angle Jack

10 to 16-Pin Power Cable

5 x Nylon Potentiometer Spacers (optional but recommended)

5 x Black Knobs (optional)

Drilling the Panel

Drill out the panel using the guide below as a reference. You can drill straight into the drill guide holes.

Cutting the Traces

The following instructions are for turning the AstroNoise into a completed eurorack module. If you came here from the very beginning of the page, the first thing that needs to happen is a small cut along a few traces. Please see the image below to see which traces to cut. It is imperative that the very bottom trace in the picture IS NOT CUT. This trace delivers +5v to one of the ICs.



If you’ve already soldered the on board components onto your board, and are ready to mount the AstroNoise to a Eurorack panel, please continue reading for the instructions. Note that we aren’t populating the 9V DC jack, battery clip or LED.

Power Jumpers

03_closeup_jumperWe are going to be soldering the 10 pin shrouded power header in the Mod_B section on the underside of the board. In order to get power from there to the proper spots, we need to run a couple jumper wires.

The first is a short wire that connects the ground. Using the picture above as a reference, solder the wire from the very bottom left hole to the fourth hole up on the left.

The second wire goes from the third hole down from the top on the left, over to the ‘S’ solder pad for the DC jack. Once you have your wires soldered in, clip any excess on the top side of the board, and make sure to cut the ones in the mod section as close to the board as possible. This will help your power header sit nice and flat when you solder it in.

Power Switch Jumper

Next up, we need to take a resistor clipping (or small length of wire) and solder it where the ON/OFF switch goes. This makes it so the astronoise turns on when your eurorack system gets power, instead of having to turn it on with a switch. astronoise_power_jumper

10-Pin Power Header


Next up is the 10-pin shrouded power header. Make sure when inserting this into the board that it looks exactly like the picture above, otherwise your power rails may be misaligned. Insert the header so that the key is pointing towards the edge of the board and the topmost row of pins goes into the row marked ‘8’ on the silkscreen.

Potentiometers Part 1

This will be step one of two for the potentiometers.

05_potsWe are going to start with the potentiometers, but only the ones labeled Volume, OSC2, and OSC1. When you have them populated, carefully flip your project over and solder ONLY the middle pin into place. Then you can go back and make sure everything is seated fully, and straight.

06_pot_closeupNext, place your nylon spacers over each potentiometer. These will help keep everything straight when you mount it to the board.


Now insert the assembly into the front panel, making sure to get the pots fully seated. Then tighten down the included nuts with a tool. Once everything is mounted and straight, you can solder the remaining pins on the potentiometers.

Potentiometers Part 2


Snip the PCB pins off of the two remaining pots so they look the like picture above. Next, solder short wires to the pots and attach them to the board as shown above. They should be soldered into the Rate and OSC_LVL spots.


Next, slide the nylon spacers onto the potentiometer shafts, then mount them as shown, with the leg side of the bodies pointing towards each other. Tighten them down and double check one last time that they are straight.



Next up are the switches. There are two, an SPDT center off and an SPST switch. The SPST switch only has two legs, while the SPDT center off switch has three.

Mount the SPST switch in hole just below the potentiometers you mounted in the last step and wire it up to the OSC_ON/OFF position on the underside of the board. The orientation on the board doesn’t matter, just solder one wire into each hole.

The SPDT  center off switch goes in the hole above the potentiometers and is wired to the board inside the TONE box on the underside of the board. As long as the middle wire from the switch goes to the middle solder pad in the TONE box, it doesn’t matter which spots the other two get soldered to.



Now we can prep the jacks. There are three jacks: one of them is right-angle, the other two are the normal solder lug style. The hole spacing on the panel is really close to the board, so the jacks must be installed in a specific way in order to not hit the rail or each other.

Start by cutting wires for each jack to an appropriate length, leaving yourself a little extra just in case you made it to short. Solder these wires to the legs of the jacks (except the ‘C’ leg of one of the solder lug jacks – this leg can be clipped off if desired).



The picture above, from left to right, shows the output jack (OUT on the PCB; wire the S and T leads only), CV in jack (CV), and then oscillator input jack (OSC_IN). Once the wires are soldered to the jacks, mount the jacks to the panel, then solder them to their corresponding places on the board.


Here’s a close up of the jack orientation.


Once everything is soldered in place and looks just like the picture above, just clip all your excess wire.

Completed Unit

Congratulations! You just finished the Eurorack mod for the AstroNoise! If you are having trouble getting it to fit inside your rails, double-check that you have the jacks oriented properly, as if they aren’t turned enough, they can interfere.



  1. Synthrotek says:

    Hi Clement, It matters on how you wire up the jack, but if you follow our instructions it will be 9V center negative

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