Elektor Vocoder, part 1
Upon stumbling across the documentation for Elektor Vocoder circa 1999, this very complex piece of diy made it to my to-do list immediately. I knew I just had to complete one some day! The project took it’s first step forward when around august 2003 I found a Tandberg TR2075 stereo amplifier in the dumpster. The casing, made almost entirely of thick clear plexi glass, was just something I could not pass up on. Its size and style just made me think of just one thing, the Elektor Vocoder. Bring it on then! I decided that since the casing is all dumpster material, maybe the electronics could also be built using as much recycled parts as possible. Make it a real Vocode-A-Trash Deluxe ™!
As the design is rather old (circa 1980), the first issue prior to etching any boards was to check the combined parts list for obscure/obsolete items. The only difficult ones were the Siemens connectors used to interface all the boards together through the backplane. Despite extensive searching, I didn’t come across suppliers or matching replacements either. Lucky for me, there were plenty of excess 3×32-pin DIN41612 bus/backplane connectors at work waiting to be binned; these were easy enough to modify to match the pin spacing on the boards (verifying against paper prints ftw!). The second issue were the etching masks for the boards. The scans floating around in the net were piss-poor quality jpgs and thus cleaning them up took quite a while. Nonetheless, the editing needed to be done so I’d get my hands on some real boards and see how the whole structure would fit the casing. CAD, now wtf is that.
These two things out of the way, I immediately broke the zero budget concept and bought the first batch of photosensitive PCBs for etching. Surprisingly enough, sourcing these from a dumpster might’ve proved a bit too much of a challenge even to myself ;)
With the casing cleared for modding and the first set of boards out of the way, it’s time for a christmas break..
Present Day Update: Little did I know that opting to use as much recycled parts as possible would turn this project into the lengthiest one to date. It’s not like I had a single clue about the time required to come across as many parts as this project requires. I knew I had to buy some of the parts (like the photosensitive boards) but was initially aiming for too a high recyling percent. Eventually, just to be able to bag the project some day, I ended up buying a bit more parts than what I originally planned.