The contact bounce is easily filtered with a simple resistor and capacitor (RC) filter before the signal goes into the CMOS commutator circuit. The signal level preceding the filter network must be limited to twice the threshold voltage of the CMOS device. In this way no timing distortion will be in...

Re my e-mail to John R. Grant (95.12.30) and his reply. John, I believe there IS a fundamental difference between electric valves and electric "key-pushing" transducers: the former is a low- power control device, while the latter is designed to produce _big_ power (force x distance). In modern solen...

Hello Larry, I am impressed by the fact, that you built a device with a technique I became aware of ten years later. This could for sure be used to built a format free note roll reader. But I am still searching for a modern, "state of art" solution without mechanical parts. Neverless many thanks for...

-- [ From: Jack Kane * EMC.Ver #2.10P ] -- Does anyone know a source for the optical board (??) which people are using to read piano rolls? (Like the device used in the "Optiola".)

Mark Fontana has given us his roll-editing thesis proposal, and Jody has suggested a CO2 laser as the output device. I've always wondered if the system for those laser-cut greeting cards might be appropriate, ever since they appeared in stores ten or fifteen years ago. Anyone have a friend or relati...

I recall seeing an unrestored Soloelle system piano. The instrument was a Knabe upright made in the 1920's. I was expecting it to be an Ampico but it was more like a standard player. The Soloelle mechanism was an expression device built into the hammer rest rail. The rail was cut into approximately ...

Amica Ampico Article: Fifth and final installment of comments. 9. "Indeed, the Model B device is an amplifier; but it is not a true crescendo. This single amplifier affects the suction supply to both 'C' pouch regulators simultaneously." p 71, para 7. ANS: In the first place, Jeffrey isn't aware of ...

In a message dated 96-11-05 00:53:05 EST, you write: > Subject: Christmas Music Box > > I have seen the above mentioned device at our local discount store. It > is priced at $59.95 Dear Bob,¶ Thanks for the information. BTW, no one has said what tone production is present. That is, does it have a st...

My name is Bob Fitterman. I just joined the group and at Jody's suggestion I am writing this introduction. I have always had a passion for mechanical devices. I've accumulated a selected assortment of old office equipment and cameras. I played the piano from a young age and have a fond memory of my ...

I found instructions with both of my tracker bar cleaners. I'll para- phrase the instructions which appear on the Ampico box and on a sheet for the Kleernote device (same pump, different distributors). The Ampico box shows a patent date of April 16, 1918. [snip -- This is the same data as reported i...

The mention of Ed Freyer's roll perforator in last evenings MMD reminded me of the time I visited Ed some 20 or more years ago. I was very interested in perforators, just having understood the operation of the interposer, a device which is put between the punch and the cam when one wants to actuate ...

[ Dan Wilson discusses a different type of surge: static electricity [ charges (related to lightning) which discharge in a few microseconds. [ The "line conditioner" device handles slow surges which occur over a [ few milliseconds -- 1000-times the duration, but a bit less voltage! [ The protection ...

•I do sandblasting and the blower I use to supply air to my blasting hood is, I have been told, the suction device for the pneumatic systems used at drive-in bank teller windows to transport the document tubes. It is, I think, a motor-mounted regenerative-turbine which has identical intake and outle...

•After reading everything I could find about the key-bed lock on upright players, I found one reference which stated that the purpose of the device is to reduce wear at the key capstan. By turning the keys "off", the capstan does not "rub" on the felt at the bottom on the abstract, ergo less wear. ...

If you're going to make up your own suction unit, the Lamb Electric "Acustek" vacuum motor #116025-13 would be a good one to use. This is a two-stage by-pass device rated at 91.5 inches of water when sealed, and 102 cfm through a 2 inch orifice, continuous duty. "By-pass" means that the air used to ...

My interest in scanning music rolls goes back to 1973, when I built a "reader" for transferring music rolls to tape. The resulting tapes were used with a device called the IMI CC-3 Cassette Converter, which played Ampico instruments from cassettes. At that time, I did a number of experiments to dete...

This is a short collection of thoughts about Spencer Chase's questions about using a hand scanner to read piano rolls. The major issue that comes to mind when thinking about making an optical reader is to hold the device steady enough so that there is no movement or vibration to interfere with the r...

•For Sale. I've been asked to sell a friend's player piano. It's a very rare hand cranked Hupfeld. In America a similar device was sold as the "Pianotist" (see Bowers's Encyclopedia of Automatic Musical Instruments, p. 362, top, right side). It's in good condition. There also are approximately 20 ro...

•I got this message and thought that this might be of general interest : > Von: Damon E Atchison [SMTP:damon66@juno.com] > Gesendet am: Donnerstag, 15. Mai 1997 03:50 > An: Robert.Hopp@quercus-hopp.com > Betreff: the book mechanical music device. > > Hello, I am an owner of a '21 Beckwith player pia...

•Reg Smith wrote: > Has anyone had experience recovering the bellows on an "orchestral" type > cylinder music box I restore about 4 of these harmonium devices a year for James Brady in Indianapolis. I've written a article about restoration process on my web site. As far as leather for the bellows go...