Tsumara JD21 restoration
Moderator: Moderators
Re: Tsumara JD21 restoration
Most digital systems that feature more than a moderate number of user switches would organise them as a scanned matrix with each switch connecting together a unique combination of row and column.
With this sort of arrangement one could accommodate, for example, 64 switches with an 8 row by 8 column matrix. An explanation of this with a music tech relevant example can be found here. The examples show the columns being driven by microprocessor outputs with the rows as inputs.
John
Re: Tsumara JD21 restoration
It's also done for low res analog controls. In the past, I've used HEF4066 to do this.
- Folderol
Jedi Poster -
Posts: 18172 Joined: Sat Nov 15, 2008 12:00 am
Location: The Mudway Towns, UK
Contact:
Yes. I am that Linux nut {apparently now an 'elderly'}
Onwards and... err... sideways!
Onwards and... err... sideways!
Re: Tsumara JD21 restoration
I asked about this and they pointed out this example on eBay. (They reckon Adafruit are the best, relatively expensive but cheap ones sometimes have faulty pixels.)
Re: Tsumara JD21 restoration
Nice restoration! Though it seems a bit large, looks like he's holding a cyber dolphin
- resistorman
Frequent Poster - Posts: 2691 Joined: Sun Nov 22, 2015 12:00 am Location: Asheville NC
"The Best" piece of gear is subjective.
Re: Tsumara JD21 restoration
resistorman wrote: ↑Thu Oct 28, 2021 11:03 pm Nice restoration! Though it seems a bit large, looks like he's holding a cyber dolphin
Yes, I was a little surprised at how large it was as well
- Martin Walker
Moderator -
Posts: 20632 Joined: Wed Jan 13, 2010 8:44 am
Location: Cornwall, UK
Contact:
Re: Tsumara JD21 restoration
Martin Walker wrote: ↑Sat Oct 30, 2021 9:34 pmresistorman wrote: ↑Thu Oct 28, 2021 11:03 pm Nice restoration! Though it seems a bit large, looks like he's holding a cyber dolphin
Yes, I was a little surprised at how large it was as well
Maybe he's just very small?
- Drew Stephenson
Forum Aficionado -
Posts: 24563 Joined: Sun Jul 05, 2015 12:00 am
Location: York
Contact:
(The forumuser formerly known as Blinddrew)
Ignore the post count, I still have no idea what I'm doing...
https://drewstephenson.bandcamp.com/
Ignore the post count, I still have no idea what I'm doing...
https://drewstephenson.bandcamp.com/
Re: Tsumara JD21 restoration
I recently took possession of the revamped JD21. After spending a bit of time with it, I decided to replace the keys. I'm now a connoisseur of arcade-style buttons and nothing less than Sanwa silent will do. Having acquired an LED magnifying glass and fine-tipped soldering iron, I spent this morning swapping them out and wiring them up.
At an advanced level, electronics is like embroidery. Took a few goes to thread the 0.2mm copper wire through the ground connections, but all done now, and playing nicely. Demo next. I'm enjoying playing this with bass patches.
I was looking for a Japanese-themed strap on eBay just now, and made an ill-advised snap decision on a secondhand koi carp design. I partly blame Resistorman for this. Oh well. It is what it is.
At an advanced level, electronics is like embroidery. Took a few goes to thread the 0.2mm copper wire through the ground connections, but all done now, and playing nicely. Demo next. I'm enjoying playing this with bass patches.
resistorman wrote:cyber dolphin
I was looking for a Japanese-themed strap on eBay just now, and made an ill-advised snap decision on a secondhand koi carp design. I partly blame Resistorman for this. Oh well. It is what it is.
Re: Tsumara JD21 restoration
Fair enough. As long as I get to complain about the exchange rate and shipping for the Sanwa switches!
- resistorman
Frequent Poster - Posts: 2691 Joined: Sun Nov 22, 2015 12:00 am Location: Asheville NC
"The Best" piece of gear is subjective.