Saturday, 29 November 2014

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.

1 comment:

  1. The article is much informative which i was searching for .Nice intro good explanation thanks for sharing.