Just started my next project, which is cosmetically restoring a vintage Yamaha SK20 Symphonic Ensemble. Everything electrical works but the veneered particle board is crumbling apart, also there’s a couple cracked keys. I’ve wanted a string machine for some time, and this one has some history, being owned by a member of Vancouver local bands Black Mountain, and Destroyer.
I am an experienced woodworker and have Peruvian Walnut on the way, to replace the chasis/case. But what am I going to do with a key that’s held together with super glue? buy a 3D Resin Printer, obviously.
anyways, 40bf of walnut arrives at my work on thursday, in the meantime I can get printing (and sanding and buffing) all the keys. I think it’s going to look pretty slick when all is done, and may eventually do the tubbutec midi mod.
I’ll keep posting in this thread as I make progress. I don’t currently work Fridays, so instead I’m going in to the shop to force myself to work on this for 8 hours a week.
Great project! I’m only cursorily familiar with this board but i love a good stringer. I love divide down oscillators in general which i assume this uses. I’ll look up some details.
Gotta ask though, are you going to build an entire case out of walnut or do you have another project for it? 40bf seems like an awful lot. No judgement, I’m such a wood hoarder i built an addition on my garage to store it.
the price was so good on the walnut, even with delivery, that I kinda ordered maybe triple what I needed seriously it worked out to about $16CAD per BF.
the sk20 is cool. has a 7 voice string section, shared with a 7 voice poly synth section (different volume faders each. I believe they share VCAs, which is why its only 7 voice on the string, but also it has 7 VCAs for strings instead of one paraphonic one), and then theres ANOTHER 7 voice organ section, completely independent and you can do a split (so technically you’ve got 14 voices between the two). the synth section only has a paraphonic filter but I like the sound of it. obviously things sound great through some effects… oh, and it has a mix out, a string/poly out, seperate Organ out, and a Leslie out (dont think I’ll ever have a leslie haha). for something so simple its pretty versatile, and fun to play.
Oof. That’s relatable with the wood purchase. Grab it when the deal is hot.
That sk20 is really interesting. Not your typical stringer architecture at all. Most that I’ve used have been unlimited poly note generation by way of divide down oscillators but kept paraphonic with a single vca like a combo organ, at least for the string section. Now I’m all curious, i’ll look up some videos or something to see what it sounds like. I think this was a great era for yamaha in general, lots of really cool stuff that you don’t see recreated today.
First real success with printing a key (no distortion) as I learn about adding supports while printing and what does and doesn’t work. Hopefully they all work out in the next batch attempt. I can squeeze 4 whole tones on the print bed at a time.
Also, my walnut arrived and it looks gorgeous. Incredibly dark and of a tone similar to the faux veneer on the synth already, so there wont be a huge aesthetic change.
Hi, it looks like Syntaur has some replacement keys for around $12 each so you could possibly check with them to see if they have the one that you’re repairing.
Oh nice, I looked before but couldn’t find parts. If the 3D print doesn’t work like I want I’ll look into that (no inverse colours though). I also have a plan to machine ebony fader caps with white acrylic inlays on top and 3D printed grippy insert structures on the inside. Inspired by some some ebony guitar knobs I have that look amazing.
After a lot of Trial and Error I have come up with a reliable method of printing 7 whole tone keys (ie an octave) in a work day. I have 2 octaves of keys so far (lots of sanding and buffing ahead of me!), and should be done printing all the whole tones by end of thursday. On friday I’m coming in to the shop to get started on the woodworking.
Just Dry Assembled at the moment. The top mitre parts need a little adjustment.
Next step will be routing a panel window in the back for the power plug and fuse, and glueing up some pieces to make a fitted bottom. My hands are stained purple from the walnut, forgot that it does that.
Oh and I decided that I’m going to go with tapered wooden legs instead of buying a new keyboard stand.
I think it’ll be a couple weeks until I get another full day in, since we use a buddy system for safety and I don’t think anyone is going to be in for a few Fridays.
The veneer is 100% plastic, I can see the cross section. That’s why it has a grain texture to it, so I guess a step up from the paper stuff (more durable too), but not real wood veneer.
I’ve been considering the midi mod. I’m alright at soldering but removing and replacing the control ic makes me nervous. Maybe worth it to get a quote from my local shop (nightlife electronics).
Fader caps are a ways out, I still need to order some ebony turning blanks to machine them out of, but I’ll give you a shout when I get around to it!
UPDATE: took the day to work on this since I haven’t been able to get in on Fridays (no one here),
Anyways, lots done. The body/chassis is basically done. I purchased the legs, they were about the same price as a cheap stand, and is a nicer touch, they unscrew for transport or to put on a tall stand, but it sits at about piano height.
I’m glueing up the parts in chunks to make finishing easier. Some things need some tweaking and little hand touches.
While I waited for glue to dry I sanded and buffed an additional 18 keys. Not pictured but the other day I printed a test of the white Sharp key model, and it looks like I got one or two dimensions off, so I need to tweak the model.
I’ve only spent two full work days on this now, not including lunch and coffee breaks, or the hours I spent reverse engineering the keys…
Okay haven’t been able to come in on Fridays because work is slow, and no one else has been there (buddy system for safety). Long story short, we’ve been on a quasi 4 day work week for over a year now. I’ve been using a vacation day every other week to even out my paycheques, but I’m running low. I think I need one more 8 hour day of taking care of fine details before I can start spray finishing.
So not much progress, but I think I’ve got the sharp key design down (maybe one more tweak needed). The ones in the picture haven’t been sanded or buffed, but look pretty cool.
seriously it worked out to about $16CAD per BF.
