We find that wiring a MFOS PCB to the front panel controls is both time consuming and often detracts from the overall finish. We are not able to alter the MFOS PCBs to make panel wiring easier so we approached the problem from a different angle. We chose to mount the front panel controls on a mini PCBs (breakout boards) that take the panel controls to a JST type XH socket into which is plugged a lead (not included with set but available separately). This lead is then dressed to the main MFOS PCB (or sometimes to other panel controls) and soldered into the respective pads. Many breakout boards have solderable jumpers for making common connections as well as thin tracks to cut where panel mounted resistors need to be connected inline with say a pot wiper. MFOS projects may require multiple breakout boards so we bundle these altogether and offer them in one ST Synth Panel Breakout PCB Set. The pack description will further describe the wiring colour code and what if any links need to be made or cut.
This method does have other advantages other than just time saving and appearance:
- Time saving
- Neater more professional appearance - improves resale value
- Takes care of common connections between panel components
- Has space to accommodate panel mounted resistors and capacitors
- Can improve reliability - have you tried soldering a diode, LED and a wire to one pin on a toggle switch on the 16-step sequencer?
- Makes fault finding easier
If you have any reservations about using connectors, then simply solder wires direct to the breakout boards. Takes longer but you still get all of the other advantages.
The boards are designed to fit our front panel component spacing so you will see references to pitch and whether it is in the 'x' or 'y' or both direction. At the time of writing, there was 30+ breakout boards developed for pots (using pot brackets), sockets (jack and banana), switches and LEDs. Whilst these will not take care of every panel component on over 40 MFOS projects, it will go a long way to achieving it. As we work through making up each MFOS project with these breakout boards, we will see where improvements can be made or even create more breakout boards to provide the best possible solution.
The panel PCBs can also be used with our YuSynth range. YuSynth PCBs are better laid out as regards panel wiring but can still take advantage of these breakout PCBs.
This pack contains the following breakout PCBs:
- 7210-703 x 2
- 7210-704 x 1
- 7210-757 x 1
- 7210-758 x 2
Whilst you can solder wires between the breakout PCBs and the main PCB, we do recommend using our JST cable assemblies. For the Noise Toaster, you will need the following:
- 7210-109 x 4
- 7210-112 x 2
See the Build Guide tab for wiring information on how to use these breakout PCBs with this module.
Whilst our breakout PCBs make the task of building a Noise Toaster easier, it still should only be undertaken if you have a reasonable understanding of assembling electronics and soldering. We have taken all reasonable effort to document this build below but should you find any errors, please let us know by posting on the FAQ tab, thank you.
- Assembled MFOS PCB #7210-071
- Front Panel #7210-571
- Back Panel #7210-871
- PCB Holder #7210-971
- 3-Way Pot PCB #7210-703 (2 reqd.)
- 4-Way Pot PCB #7210-704 (1 reqd.)
- 4-Way Toggle Switch PCB #7210-757 (1 reqd)
- 3-Way Toggle Switch PCB #7210-758 (2 reqd)
- 9-way Cable Assemble #7210-109 (3 reqd)
- 12-way Cable Assemble #7210-112 (3 reqd)
- 25mm spacers with an ID of 4mm #TBA (4 reqd)
- Bracket Kit #7210-181 (1 reqd for modular mounting or 2 if mounting in a hardwood case)
- PCB Mounting Fixing Kit #7210-182
- Pot mounting brackets #7300-000 (10 reqd)
- Additionally you will need our Switchcraft Jack Sockets #7212-200
Not all panel components use our breakout PCBs, some will require soldering direct but these will be described in the following guidelines.
Panel PCB Preparation
Firstly, make sure the solder bridges where specified are done before assembly as it is very difficult to solder G afterwards. There a few PCB track links to cut but these will be highlighted in the photos.
- Solder in JST headers noting that the slots in the socket housing point towards the top of the board on the pot
- Remove any anti-rotation lugs on the pots
- Insert pot into bracket and temporarily do up lock nut
- Insert pot with bracket into PCB and solder in position ensuring the pot bracket sits flat on PCB. Only solder the bracket lugs on the bottom of the board
- Repeat for remaining pots
- Remove pot nut
VCO Pot PCB requires bridge 'D' soldering
VCF Pot PCB requires R4 option track cutting using a sharp knife or dremel style tool.
On the front side of the VCF Pot PCB, solder in wire links between R1/R2, R7/R8 and an insulated wire between R3/R7 (not too short). Also solder in a 27k resistor in postion R4 (this is why the track underneath had to be cut)
Now for the LFO / AR Pot PCB. Cut option tracks R4 & R7
On the front side of the LFO / AR Pot PCB, solder in wire links for R1/R2, R5/R6, R8/R9 and an insulated wire between R6/R8 (again leaving a bit on the length). Now solder in the two 1N914 diodes noting the polarity in the photo below.
The 4-Way switch PCB requires a non-polarised capacitor soldering between pads X8 and one end of R9. Solder bridges L4 and L8
The remaining two toggle switch PCBs need no initial preparation. So you now have 6 breakout PCBs ready for populating.
Solder in the JST connectors noting their orientation.
Solder in the pots as per the General Instructions in the opening text in this guide.
Now assemble the front panel with the switches and socket. The picture below is the PCB holder arrangement for modular synths but if you are mounting the Noise Toaster in one of our hardwood cases, then fix the angle brackets as below but do not attach the PCB holder as per the second photo below. From this point, the photos will relate to the hardwood case arrangement which as it happens is also suitable for modular cabinets as well.
Onto the wiring, plug in the 9-way JST into the VCO pot PCB and dress the wiring as shown. Cut the green and grey wires as not needed. The table below summarises the wiring required and unless otherwise stated, these are references to the main MFOS PCB. Do not solder the wires to the MFOS PCB for this and the subsequent breakout boards just yet but refer back to the associated tables below when the instructions direct you to.
VCO Pot PCB (Don't cut any of these wire to the MFOS PCB short, leave at the supplied 300mm)
|4||Yellow||Wire to R10 on 4-Way Pot PCB|
|7||Blue||Gnd (pad just to the side of BP)|
Plug in the VCF Pot PCB cable. Cut red, green, blue and violet wires as not needed.
VCF Pot PCB
|1||Black||Wire to R7 on VCO Pot PCB|
|4||Yellow||Wire to R1 on VCO Pot PCB|
Plug in the 4-Way Pot PCB cable. Cut teh green, violet and grey wires.
4-Way Pot PCB
|2||Red||X9 on the 4-way toggle PCB|
|4||Yellow||X11 on the 4-way toggle PCB|
|7||Blue||R11 on the 4-way Toggle PCB|
Plug in the cable for the VCO toggle switch PCB. Cut the black, yellow and blue wires.
VCO Switch PCB
|2||Red||To X1 on the VCF toggle switch PCB|
|3||White||To R9 on the VCO Pot PCB|
|6||Green||To R2 on the 4-way Pot PCB|
|8||Violet||To R3 on the VCO Pot PCB|
Plug in the VCF switch PCB. Cut the yellow wire.
VCF SWitch PCB
|2||Red||To R6 on the VCF Pot PCB|
|3||White||To R6 on the VCO Pot PCB|
Plug in the 4-Way switch PCB. Cut the white, yellow, blue, violet and black (no.11, not no.1) wires.
4-Way switch PCB
|2||Red||To R12 on 4-Pot PCB|
|5||Orange||To R6 on VCO Pot PCB|
|9||Grey||To LED1 Cathode|
A few extra wires to run before we start to solder to the MFOS PCB.
- blue wire to the LED anode, the other end to X23
- yellow wire to the push button, the other end to X21
- green wire to the push button, the other end to pad X8 on the VCO switch PCB (not the VCF switch PCB as per the mistake in the photo below)
- orange wire to the jack socket pole, the other to X24
- violet wire to the switch contact, the other end to X27
- blue wire to R1 on the VCF pot PCB
Grouping the wires in readiness for soldering to the MFOS PCB
The next photo shows how the PCB holder can be made to lie flat through the use of another pair of Soundtronics angle brackets. For now, do not bolt the two pairs together.
We solder the wires from the top of the PCB which works juts fine using a fine tipped soldering iron. Using the wiring tables for each of the breakout PCBs described above, you can now solder the loomed wires to the MFOS PCB.
Taking each group of dressed wires, one lot at a time and soldering then to their respective pads.
All wires now soldered to the main MFOS PCB. Just two wires left for the power supply. The speaker wires have not yet been soldered to the PCB.
Notice the way in which the wiring has been dressed so as to make it easy to lift up the PCB holder in case you need to gain access to the controls behind in the future.The speaker wires are connected to X26 and the adjacent unmarked pad (next to C20).
Erratum - Note how the green wire from the push button is now correctly wired to X8 on the VCO switch PCB, above instructions correct so you should not have made the same mistake.
Notice how the two pairs of angle brackets are screwed together using M4 screwss.
Our hardwood case for housing the Noise Toaster complete with base ready cut out for the speaker and battery holder
The battery holder is held in place by using M3 countersunk screws and nuts. The speaker is simply glued in place using a few drops of super glue around the outer edge. Place a PP3 battery clip into the battery holder and solder the tails to the brown and grey wires - Red to grey and black to brown assuming you have used the same colours codes as we did. Test everything before final assembly.
Using a fine tipped pencil, mark where the case needs drilling for the panel mounting screws. Remove the panel and using a 1.5mm drill bit, drill the 4 holes to a depth of about 4-5mm. We recommend the use of our stainless steel No. 4 x 9.5mm self tapping screws with a Torx head.
Pop in a battery and you are ready to enjoy the wonderful sounds from the Noise Toaster. Our kits do not come with the knobs shown in the photo below but is supplied with a different type we use on single board synths and sound effects units.
If you do not get any white noise, try replacing Q5 with another 2N3904 as some have too high a Vbe value - trial and error.
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