MATRIXSYNTH

EMSA -- Electronic Music Studios of America

via David:

"Peter Forrest's post to AH about EMSA led me to do a little digging. I lived in Amherst, MA, years after EMSA but still love the area. Anyway, Everett Hafner's (owner of EMSA) daughter put up a page about him, including a seriously photo-laden picture of EMSA stuff"

Update: Be sure to check out the EMSA link below for all posts featuring EMSA - there are only a few including this one, however there is some fascinating history including the Ionic Performer.

Stribe 0.4a w/ 0.4g Max patch + DSI monosynth

YouTube via soundwidgets
"A mini-demo of the very basic Max patch I wrote for the Stribe. It's essentially a 'virtual stribe' that sends display messages to the Stribe, and receives sensor data from the touchstrips and displays that in rslider controls. You can actually play with the virtual stribe without a real Stribe, but it's just not the same."

Analog Synthesizers アナログシンセサイザー

video upload by kiewmission

"TOKYO GEIJUTSU DAIGAKU THE 120TH ANNIVERSARY
Buchla, MoogIII, ARP2500, Roland System 700 & 100M.
東京藝術大学　創立120周年企画
音響研究室アナログシンセサイザー展示"

Roland TR-606 "Drumatix" Analogue Drum Machine

YouTube via retrosound72

"short demo of the Roland TR-606 drum machine by RetroSound

The little sister of the Roland TR-808 drumcomputer. The TR-606 has analogue TR-808 like sounds and the typical LED step programming."

How to Repair a Poly-61

Click here for a website on how to repair the Korg Poly-61 via Michael.

"Welcome to my documentation of the odyssey repairing some Poly-61s, as i recently bought 3 of them with the intention to get at least 2 of them working perfectly. If you want to repair a Poly-61, i have to warn you - it is quite a lot of work to get it perfectly working again, if it has the full repertoire of usual problems of this synthesizer. First of all, if you don't want to do a full restoration, you should know a bit about the inner workings of the Poly-61. This is where i want to start. So let's have a look at the anatomy of the Korg Poly-61."

Update: unfortunately the link above is gone. I found the following from Really Nice Audio:

POLY61 RepairS video upload by Really Nice Audio

"By changing the switches and cleaning the keyboard contacts you can bring a synth back to its former glory."

Continuous Signal Processing: The Fourier Series

via AH regarding the following question:

"Does anyone know the formula for calculating the resulting harmonics the formula for calculating the resulting harmonics of a pulse wave when the pulse width is varied? In other words, a square wave (or pulse wave with 50% duty cycle) has only the odd-numbered harmonics present; how do you determine the harmonics present when the duty cycle is 25%, or any other value?"

Dave Manley followed up with a link to this site.
"This brings us to the last member of the Fourier transform family: the Fourier series. The time domain signal used in the Fourier series is periodic and continuous. Figure 13-10 shows several examples of continuous waveforms that repeat themselves from negative to positive infinity."

Update: also see this Synth Secrets article on Sound on Sound.

ARP Omni and Omni 2 Repair Page

On marksmart.net:
* Common failures on the ARP Omni and Omni 2
* 4075 Filter modification
* Power supply modification
* Imitating ARP string sounds
* ARP slider caps