Entrant:
GGBB/GordPedal:
Orange Smoothie CompressorThis compressor project started life as a desire to build an Orange Squeezer with modifications. As I searched for potential modifications and other improvements, I came across Mark Hammer's modified Orange Squeezer and decided to pursue his dual op-amp idea as well as the variable gain and brightness controls. Eventually the pedal would become much more like another of Mark's designs - the Tangerine Peeler, but a lot less complicated, and with a few enhancements, plus all the bells and whistles.
As much as I'd like to go into the details of this pedal's complicated evolution, I will spare you the gory details. Suffice it to say I had no idea that I would end up with such an amazing pedal when I set out to build myself a lowly OS. I really learned a lot doing this build. Two things stand out - I definitely need finer solder, and I probably need a smaller tip for my iron. All kidding aside, I'm glad I entered this contest because it really pushed me to be a better, smarter builder, and because I know I have improved on my past pedals.
Features:Side-chain Processing - The dual op-amp design allows compression to take place outside of the audio path.
Band-pass Compression Filtering - Toggle switch enables high pass filter on the compression signal to retain dynamics on low notes and bass-heavy chords.
Quiet Bias Supply with True Vref - Reduces AC noise from DC supplies - a common problem with stock Orange Squeezers.
Low Power Consumption - Circuit draw is about 4.5mA. Super-bright LED with 6.8K resistor draws about 1mA.
Variable Compression RatioAdjustable ThresholdAttack and Sustain ControlsActive Volume ControlBrightness ControlReverse Polarity Protection - Series 1N5817 Schottky.
Build Details:Compression Diode - BAT48 Schottky.
Capacitors - All electrolytics in the signal path are tantalum. All other caps are mica or film.
Op-amp - I tried many, including some exotic ones like the OPA2134, and a rare one (MC1458S), but the TL072 had the best balance of neutrality and low noise IMO.
Layout - Designed my own - all pots are board mounted - off-board connections are strategically placed for close proximity to connected item.
PCB - Etched my own - this was my first time. Toner transferred a component and connection guide on the reverse side.
Paint/Graphics - White enamel primer; orange enamel paint on sides and back only; colour laser printed waterslide decal on top with bubbly orange smoothie picture background; enamel clear coat (to make the decal transparent); water-based polyurethane top coat.
LED - It's orange!!!!!
Video:This is just a quick short low quality video demo to show it working live. The full demo is the MP3 file below.
Audio:http://soundcloud.com/ggbb-music/orange-smoothie-compressorPictures:
Schematic:
Layout:
PCB Transfer:
Screen Transfer:
Credits:Based on the Dan Armstrong Orange Squeezer from J.D. Sleep (generalguitargadgets.com) and the Tangerine Peeler by Mark Hammer (hammer.ampage.org). Threshold control idea by Mark Hammer. Brightness control by Jack Orman (muzique.com). Compression control by G. Tranter and 'free electron'. Attack control by G. Tranter from Mark Hammer and Jon Patton. Sustain control from Mark Hammer, Jon Patton and others. Thanks to R.G. Keen (geofex.com) for 'The Technology of the Orange Squeezer' and Aron Nelson (DIYStompboxes.com).
I am planning on putting together a build guide for this in case anyone is interested. The enclosure I used was a 1590N1 so the PCB is 2.4x1.6", but I also have a 1590B sized version of the layout and transfer - just PM me if you want it - I will post them somewhere eventually.
Good luck everyone - this is an amazing competition - I had a lot of fun building this pedal.
