Boy Meets Synth

I do love a good stringer. Ive worked on a Yamaha SK20 and a Roland RS-09 and RS-101 . This time it’s a Korg Delta DL-50 Strings Synthesizer, a lovely machine from 1979. It came out as part of Korg’s series of three Greek letter-named polyphonic machines. There was the Sigma and Lambda, both of which were largely preset machines, and then the Delta, which arguably offered the most control (until the Trident came out in 1980 and blew it out of the water). The Delta is fully polyphonic, no mean feat then or now. Before you get too excited though, it’s basically just a glorified organ. It uses three divide-down oscillators to create all the notes (plus one more for high C). So yes, you can hold down all the keys at the same time but you’re limited to a square wave. A very nice square wave, it should be noted, but just that one waveform nonetheless. The sound is further divided into synth and string sections, the former of which is pushed through a variable filter (low or bandpass), ...

Summer vacation had arrived. I finally had time to do all the work on the Juno-106 that I needed to do. And there was still quite a bit that needed doing: new battery, new tact switches, rebuilding the sliders, cutting out fader dust covers, and doing something about those ugly buttons. Being a junior high school teacher, I had the whole summer off to get things done. Here’s how it went. Starting with the battery seemed like a good idea. Although the old one was still putting out a good amount of charge, I figured since I was ripping everything out I may as well get the module board out too. I unplugged the numerous amount of cables, got the board out, and swapped out the battery. No sweat. The next order of business was getting the panel board out from under the top of the synth to deal with all the things that needed addressing there. Out came the many cables running into the panel board, off popped the slider caps, and out slid the board from its slot under the panel. I pulled...

Although I love my Yamaha SK20 , as a string machine it honestly leaves a little to be desired. Sure, it has some nice strings but it’s more of an all-around 70s synth than a satisfyingly smooth stringer. For that, I needed a Solina. And because I’m just a humble junior high school English teacher I settled for a Roland RS-09. There are plenty of string machines that will do more than the RS-09 but where this thing excels is the ensemble effect. Four (count them! Four!) bucket brigade circuits work together to create a glorious, heavenly whirlpool of phasing sound. There are two speeds, slow and less slow, and they’re both luxurious. I could hold down a chord and listen to the cycling BBD magic all day. And if that wasn’t enough, the RS-09 has an external in so you can add a touch of heaven to any signal you want. You may remember that this is not my first dance with a Roland RS synth. While this one didn’t stink like my RS-101 it did have a number of other problems lurking belo...

I thought I’d take another crack at Stinky Boy a.k.a. my Yamaha SK20 Symphonic Ensemble . He’s been doing great but I still had some unfinished business to take care of. And truth be told, he still hadn’t completely given up his old synth smell. I dragged all 33 pounds (15 kg) of him down from the loft studio and popped him open. (I have to say, they really designed synths for ease of maintenance back in the day. Just a few screws and up pops the control panel. Even the keyboard is on hinges.) My plan was to rebuild the sliders, change the tact switches, redo the terrible dust covers I had put in temporarily last time, replace the strip of felt from the top of the keys, and address the smell. I recently finished refurbishing a Roland SH-09 (which I hope to write about soon) and part of that involved rebuilding the sliders. There were only 10 and it took all day, and it really didn’t make a huge amount of difference. So instead of spending a lot of time on the SK20’s 29(!) sliders, I ...

What is it with me and stinky stringers? After my debacle with a moldy Roland RS-101 you’d think I would have learned my lesson. But nope, here I am with another moldy string machine, this time a Yamaha SK20. Don’t worry if you’re afraid of more heartbreak though. This one has a happy ending. Released in 1980, the SK20 was part of a series of “symphonic ensembles,” machines that combined organ, string, and regular synthesizer functions. The SK20 was on the lower end of the range, lacking the solo (monophonic) synth of the SK30, but still fairly robust with five octaves and seven notes of polyphony. With its half-matte black metal front, rosewood grain end panels and wooden base, and yellow and gray buttons and sliders, it looks very of its time, when instruments were made to look like furniture and 33 pounds (15 kg) was considered light and compact . Although similar in appearance to the M-appended entries in the CS series, the SK units are less synthesizers than string machin...