Search found 26 matches

by stefanv
Fri Oct 23, 2015 9:05 pm
Forum: PAiA Jabber
Topic: Chord EGG 2015
Replies: 23
Views: 79376

Chord EGG 2015 - Tone Generator

Rather than wait until I'm done to write up my notes, I'll do that as I go along, and share the images in this forum. This evening, I completed the tone generator portion. Instead of a top-octave chip, it uses eight separate op-amp oscillators, built around a pair of TL074 quad op-amps. Here is the ...
by stefanv
Fri Oct 16, 2015 12:30 pm
Forum: PAiA Jabber
Topic: Chord EGG 2015
Replies: 23
Views: 79376

Re: Chord Egg 2015

Time for another update. I've finished a circuit board layout (I'll be using stripboard), and have started making the board. It's 2.7 x 7.7 inches. How does that compare to the original? My eventual plan after playing with it for a while is to make it into an alarm clock, using the Chord Egg sounds ...
by stefanv
Fri Jul 03, 2015 3:33 pm
Forum: PAiA Jabber
Topic: Chord EGG 2015
Replies: 23
Views: 79376

Re: Chord Egg 2015

I happened to have a pair of LM3900 chips, so I decided to breadboard the Chord Egg oscillators to see what their actual periods and duty cycle are. Here's what I found: First, the chord randomizer oscillators. According to the Design Analysis in the manual, these two oscillators should have a perio...
by stefanv
Tue Jun 23, 2015 7:27 pm
Forum: PAiA Jabber
Topic: Chord EGG 2015
Replies: 23
Views: 79376

Re: Chord Egg 2015

Just wanted to update everyone (anyone?) on the progress. I've got the basic design completed (schematics only at this point, no layouts), but I'm slightly stuck on the filters. I'm not all that familiar with current-feedback op-amps like the 3900, but it was easy to redesign all the time interval g...
by stefanv
Mon Apr 27, 2015 8:58 am
Forum: PAiA Jabber
Topic: Chord EGG 2015
Replies: 23
Views: 79376

Chord EGG 2015

I've recently become intrigued by the Chord EGG, and have in mind to design a new version not requiring any hard-to-get parts. I've already got the design pretty much fully formed in my head, and half of it down on paper (hint: it still uses only 5 chips like the original, but all 5 will be the same...
by stefanv
Mon Apr 16, 2012 12:26 pm
Forum: PAiA Jabber
Topic: Paia Proteus 1 knobs.
Replies: 6
Views: 20909

Re: Paia Proteus 1 knobs.

Do you know if these are the same knobs as the ones used on the Stringz'n'Thingz? If so, I have a bunch of those since I completely transplanted my Stringz and used very different knobs on it.
by stefanv
Sat Apr 07, 2012 11:40 am
Forum: PAiA Jabber
Topic: Stringz'n'Thingz Noise Reduction
Replies: 0
Views: 12780

Stringz'n'Thingz Noise Reduction

About two years ago, I posted a thread about my project to rejuvenate and expand an old PAiA Stringz'n'Thingz string synthesizer. The project went well, but in recent times the various unintended noises that it made started to annoy me, so I spent a few weeks tracking down some gremlins, and improvi...
by stefanv
Fri Oct 08, 2010 12:49 pm
Forum: PAiA Jabber
Topic: New member, with a vintage PAiA Stringz'n'Thingz
Replies: 11
Views: 45723

Re: New member, with a vintage PAiA Stringz'n'Thingz

Cool. I just went to look at it, and it took me a long time to find it. Is it just me, or do others find Keyboard's web site really difficult to navigate?
by stefanv
Wed Sep 01, 2010 7:59 pm
Forum: PAiA Jabber
Topic: New member, with a vintage PAiA Stringz'n'Thingz
Replies: 11
Views: 45723

Re: New member, with a vintage PAiA Stringz'n'Thingz

Thanks toneman!

I just picked up the September issue of Keyboard Magazine, which has Devo on the front cover, and a quarter-page blurb on page 11 about my project, complete with a link to my article!
by stefanv
Mon Jul 05, 2010 11:55 am
Forum: PAiA Jabber
Topic: New member, with a vintage PAiA Stringz'n'Thingz
Replies: 11
Views: 45723

It's Done!

About a week ago, I completed my Stringz'n'Thingz rejuvenation and expansion project. It certainly took longer than I'd planned, but it's finally done! What I ended up with is: 44-key Yamaha keyboard (7 additional notes) in a new case. Octave-switchable crystal-controlled master oscillator. Separate...