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Curious Inventor - Kits : Voice of Saturn Sequencer : Instructions

Kits: Voice of Saturn Sequencer

by recompas (electronic musician / composer)

--- building instructions ---

Introduction:
This guide will walk through the assembly of the "Everything" version of the kit.
1. Recommend Tools and Supplies:
  • Soldering Iron and Solder: A 15 Watt iron will may get the job done, but it'll be easier with a 25 or 35 Watt iron. The larger pot and switch connections can draw a lot of heat. Don't lose sleep purchasing your first iron; any cheap RadioShack one will do. We like small chisel or screw driver shaped tips (say 1/16th of an inch wide), but personal preference plays a big role. The goal is to use a tip that's about the same size as the pad you're soldering. This way you get you get as much surface area contact as possible (better for heat transfer) but are still small enough to avoid touching neighboring pads.

    For solder, we recommend .02 or .031" diameter, rosin cored flux, tin-lead solder, either 63/37 or 60/40, whatever's cheaper. See our soldering guide for explanations. Lead-free solder is a little bit harder to use since it "wets" metal somewhat slower and has a slighty higher melting point. If your kit has sat on the shelf for a while (a year), some steel wool or a pink eraser is useful to remove oxidation from the components and board before starting.

  • Wire: This kit involves a lot of wiring, we recommend you use 22 to 28 gauge stranded wire because solid wire is less flexible and can break as wires shift around. Colored ribbon cable is very helpful. Some colored ribbon cable can be bought here.
  • Needle Nose Pliers: Used to clinch or bend component leads, help remove components, and in this kit, remove metals stubs from the pots and also tighten nuts. (buy)
  • Helping Hands: Two aligator clips on a heavy base that are useful for holding wires while you solder them.(buy)
  • Flush Cutters: Used to trim leads close ("flush") to the board. (buy)
  • Solder Sucker or Solder Wick: Used to remove solder. (buy)
  • Clamp: A table top will be fine for most of the job, but a clamp can be handy, especially when removing components. (buy)
  • Multimeter: To check your work.
  • Wire Strippers: (buy)
  • Screwdriver: Either phillips or regular will do for putting together the case.
2. Add components to the PCB (Printed Circuit Board):

First, add the ICs making sure to line up the notches on the chips with the markings on the pcb.

Then add the other components using this list to match the "R1", "D1" etc. labels on the PCB to component values:

  • U1: LM555N timer (spec) (buy)
  • U2: CD4017 timer (spec) (buy)
  • Capacitors:
    • C1: 10uF (buy)
    • C2: .1uF (buy)
  • (13) spdt toggle switches (buy)
  • (15) 1/8" audio jacks (one switching) (buy)
  • (11) R17 thru R27: 100k linear potentiometers (buy)
  • Resistors:
    • R1: 1k (buy) (brown black red)
    • R2: 1k
    • R3: 1k
    • R4: 1k
    • R5: 10k (buy) (brown black orange)
    • R6: 1k
    • R7: 1k
    • R8: 1k
    • R9: 1k
    • R10: 1k
    • R11: 1k
    • R12: 1k
    • R13: 1k
    • R14: 10k
    • R15: 1k
    • R16: 10k
  • Transistor: Q1, 2N3904 (buy)
  • (21) Diodes: D1 thru D22 (buy) -- Make sure to line up the the line on the diode with the line on the board. Unlike resistors, direction matters with a diode.
  • (11) Red LEDS: D22 thru D32 (on panel) (buy)

To keep components in place while you solder them, clinch (bend / splay) the leads outwards. On the IC, do this for two opposite corners. This is actually what automated machines do to keep chips in place while the boards are run over fountains of liquid solder (wave soldering).

3. Soldering:

Tin the tip, or in other words, add a bit of solder to the tip, first. This small amount of solder forms a "heat bridge" to help conduct heat from the tip to the pad and component lead. When you first contact the parts with the iron tip, it's helpful to first place some solder in between the iron and components, then melt solder on the the side opposite from the iron tip. This ensures that the component is hot enough to bond to the solder, and also helps to spread out the solder as it will run towards the heat source.

On ICs, it's a good idea to solder every other pin (and then fill in the gaps) to reduce the risk of overheating the component.

Cut off the leads as you go with flush cutters. Watch out for flying leads; safety glass are actually not over-precatious for this, although we generally just hold the lead with fingers to keep it from flying off.

4. Resistors and Diodes:

(picture is from a different kit)

Pre-bend the leads before inserting to keep from damaging the board and resistor (not doing this isn't the end of the world). First hold the resistor above it's position, then hold the lead with pliers next to where the bend should go and then fold over the lead. You can also wing it with fingers. Another benefit of using pliers is that you prevent the joint between the resistor body and lead from being stressed. Resistors and most other components should be inserted as far as possible; this means lying flat for resisitor. It's convention to install resistors so their code can be read left to right in the same direction as the silk screen (tolerance band on the right).

5. Installing Pots, Switches, LEDs and Audio Jacks:
First break off the anti-rotation tab with pliers, then install like the following picture shows:
Install the LED holers from the outside, then press the LEDs into them from the inside until they snap in place. This can be surprisingly tricky. Try to keep the holder as far in as possible while pushing the LED through from the other side (this is hard because you'll be trying to get the LED to go past where you finger is pushing on the holder). Lots of wiggling will help more than lots of force. Sometimes you may have to bend out the holder legs a bit with a screw driver to loosen it up a bit.

Before wiring, it's a good idea to tighten everything down to reduce the risk of breaking solder joints later when tightening things.

6. Wiring up all the components to the board:

Once you have all the components in place, we recommend pre-cutting and stripping a bunch of wires that are about 15" long. This may seem excessive, but it's very helpful to have some room to route wires. And, in case anything goes awry, there will be enough slack to cut off some of the wire. Small gauge (24+) colored wire is highly recommended along with some zip ties.

First loop the wire through and bend it to hold it in place, then heat the joint from one side and apply soder to the other. Again, it will help to put a bit of solder between the iron tip and connection to act as a heat bridge.

Use the following wiring diagram to connect everything:


Click for larger version.

A couple tips and notes. The circuit board has lots of extra holes if you follow the above wiring diagram. This is because we wired all of the grounds together on the case, each LED, POT and many other components have their own ground return hole on the PCB, also. We did this in case someone was making their own case and wiring together the grounds wasn't feasible for some reason.

As an example, STEP 4 is shown up close both on the panel and the PCB. The 1/8" jacks don't need a ground connection, they're only there to make a connection, not pass a signal.

Note that the reset jack has been wired differently than the other jacks. It takes advantage of the "switching" nature of the jack. When a plug isn't present, the signal is shorted to ground. Also, the hold switch has the wires connected to the top two pins as opposed to the bottom two, like the rest of the switches.

Finally solder wires to the battery holder, attach the standoffs to the pcb and screw together the case. Add knobs and you're done.