Shin-Ei Fuzz-Wah - Univox/Unicord Super Fuzz - Pedal assembly (3/4)

The Fuzz-Wah was mounted on a 1590B Hammond enclosure, with two NKK M2012SS1W01 SPDT ON-ON switches, two Alpha RV16AF-10-20R1-A100K 16 mm A100K potentiometers, one Alpha RV16AF-10-20R1-A50K 16 mm A50K potentiometer, one Neutrik NMJ6HCD2 1/4'' Stereo phone jack as input connector, one Neutrik NMJ4HCD2 1/4'' Mono phone jack as output connector, one Alpha SF17020F-0302-21R-L 3PDT foot pushbutton switch, one Switchcraft 722A 2 mm DC power jack, one 5 mm blue LED, one 5mm LED bezel chrome, one 9V battery snap, and three black flute knobs with line indicator.

I buy most of the electronics at Mouser website, but some of the accessories are difficult to find, so there is an excellent German website specialized in pedals kits, components and accessories called Musikding.

It's quite hard to pack PCB, pots, jacks, battery and switches on a 1590B enclosure, so in order to design, plan and place all the different components I create a three view drawing with all the components on Inkscape. Inkscape allows copying an image from a pdf datasheet  convert it into a vectorial drawing,with the powerful Trace Bitmap tool, edit and delete lines or points, scale it and group all the lines into a single component that then can be moved and properly placed. This allows getting a better idea on how everything is going to fit in and avoid having troubles and discovering too late that a component does not properly fit. See the picture below. This is extremely useful, specially in this case, where it's extremely challenging to place three knobs and pots, two toggle switches and one foot push button switch on the faceplate. We have to be sure that everything fits in a there is enough place to add the faceplate design:

Fig 1. Inkscape three view pedal mechanical drawing

I also use Inkscape to design the faceplate. I create numbered knob dials, symbols, shapes, texts and drills as a group of lines that I can later reuse. In this case I used Aeroplane Flies High font for the Rezzonics and Rezz Fuzz v2 labels:

I did a simple design in blue and printed it on a transparent sheet. I decided rather not paint the enclosure but sand and polish the aluminum to leave it's natural metallic color and glue the transparent sheet with the faceplate design in blue. In order to better protect the laser printer blue ink, I printed the design in reverse, Inkscape allows easily reversing or flipping the design.

Water sanding to finer grains and polishing is quite a tedious work but the final chrome-like result is quite nice. Afterwards, holes are made using a multi-drill bit, I recommend using this type of drill for better results.

I used a repositionable adhesive spray to glue the transparent sheet. Faceplate shape is cut and adjusted to the enclosure after water sanding and polishing. Adhesive is applied to the transparent sheet and leave for 2 minutes to let evaporate and reduce the number of bubbles, then is firmly applied using a clean cloth with outwards movements, avoiding formation of bubbles and taking care that the faceplace keeps aligned with the borders and does not slides out of the enclosure faceplate.

The little defects, shades, and bubbles, disappeared as the adhesive dried out.

The Fuzz-Wah pedal finished. Knobs are Main volume or Level, Fuzz Gain, Wah frequency, Wah off-on switch and tone cut off-on switch. Footswitch is a true bypass.

The pedal finished and powered-on.

Tube Simulator - Practical Implementation - Chassis, face plate (3/4)

Face plate design

For the face plate design I used Inkscape. Inkscape is a free vector graphics editor and design tool for professional and amateur use. There are lots of tutorials, videos and materials for fast and easy learning. Cool free fonts can be found in the internet. It is important to install the fonts in the computer used for design but also in the computer used for printing, otherwise default fonts will be selected.
I wanted a simple design with a cool, coloured background but that could match well with the natural aluminium colour of the rest of the box, so I used a kind of steel or aluminum grey and then I used a liquid effect.
This is the result:

It's important to have the right dimensions that correspond with the placement of the potentiometers, switches, jacks and other components in the PCB layout. Since the board was mounted on standoffs in the base plate, the height of PCB and standoffs has to be considered.

The design can be very easily flipped horizontally before printing. I printed the design in A3 printing transparencies used for presentation slides with a laser printer. Since the design is printed flipped in the A3 transparent sheet, the ink stays in the side that has to be glued to the enclosure, which helps protecting the ink from scratching if it were exposed outside.

Cut out front and rear face plates from the transparent sheets and verify that everything is in the right place. You can actually see the effect of not installing the proper fonts in the computer used for printing.

Front face plate placed in position (not glued yet):

Rear face plate placed in position (not glued yet)

Chassis assembly

Before fixing the face plate to the chassis, holes must be drilled in the chassis.
Instead of using regular metal drills I recommend using a multi-drill bit and of course a drill support, a much higher precision of drilling is obtained.

Not flipped design can be printed in a regular paper, placed in position and with a hammer and a punch tool the center of the holes to be drilled can be marked.

Once the holes have been drilled, chassis cover must be put in place because very often components are not perfectly aligned or they don't have the exact diameter, so the holes must be adjusted with a file.

Once printed, the design is cut out with some scissors and fixed to the chassis faceplate using transparent glue in spray:

Aluminum chassis must be perfectly clean with no traces of dust, grease or fingerprints. Some acetone can be used for cleaning it.
The glue must dry for 2 or 3 minutes before applying to the chassis, it must be positioned carefully and properly aligned trying to avoid that bubbles form between the face plate and the chassis. Use a clean cloth and apply some force to stick the face plate to the chassis.
Once the face plate is in place, a cutter can be used to remove the face plate in those areas corresponding to the holes.

Now the chassis is fixed to the PCB and base plate, inserting the front components in their holes that were previously verified. rear components are soldered with wires to the board. Nuts are added to potentiometers, switches and jacks with black plastic spacing washers.
Insert the rubber buttons with the potentiometers completely turned anti-clockwise and the dials pointing at 0, and the job is done!!

Front view of finished chassis:

Rear view of the finished chassis

The Tube Simulator is finished, now is the time to plug it and see how it sounds!!
But wait I need a cabinet speaker to plug my Tube Simulator amplifier...