DX7
TX802
Speakers
Yahama MS101 II Monitor Speaker
16 - 300 Ohm Headphone amplifier
Roland Cube 15x
MyAmp
Radio_Shack_277-1008
PAM8610 Stereo PCB + Small Speakers
Voice of the Theater
Yamaha YST-SW315 Amplified Sub Woofer
7.1 Surround Sound
Theremin
Linnstrument
Yamaha CSF-TA Guitar
DATS V3 Audio Test System
Related
Korg M-20 Mini
Korg SQ-1
Pocket Operators by Teenage Engineering
Gecho Loopsynth
DIY Synthesizer
Home Theater - 7.1 Surround Sound
Pneumatic Operated Instruments
Links
Yamaha DX7 II Analog Music Synthesizer
In addition to equal temperament tuning there were other tuning built in:
Pythagorean
Werckmeister
Kirnberger
Vallotti & Young
1/4 Shifted equal
1/4 Tone
1/8 Tone
Patents
3577084 (Google) Computer Sound Generator May 4 1971 Singer-General Precision 327/107; 84/659; 327/134; 341/147; 377/51; 377/112; 984/389; 984/DIG1
3696201 (Google) Digital Organ System 84/648; 84/659; 84/660; 984/382; 984/DIG1 (Wurlitzer) -
4018121 (Google) Method of synthesizing a musical sound Filed: May 2, 1975, Pub: April 19, 1977 John M. Chowning 84/696; 84/101; 84/659; 984/309; 984/324; 984/389; 984/DIG1 - Basis of the Yamaha DX-7 Synthesizer.
Patents calling 4018121 -
4813326 Method and apparatus for synthesizing music tones with high harmonic content, Yamaha, Filed: Jul 16, 1984, Pub: - Fig 22 block diagram of an operator
4922795 Tone signal forming device, Yamaha, Filed: Nov 17, 1987 -
5025702 Electronic musical instrument employing time-sharing frequency modulation and variable control of harmonics,Yamaha, Filed: Jul 3, 1975, Jun 25, 1991 - FM synth (filed a month after Chowning)
5191161 Electronic musical instrument including waveshape memory and modifiable address control, Yamaha, Filed: Jul 3, 1975, Pub: Mar 2, 1993 - variable color with same pitch from table entries.
YouTube
John Chowning, Computer Music, DX7 & FM Discovery, 56:57 -
00:00 - Cold Open 00:42 - intro 02:27 - Read to Discovery 06:15 - Stanford & Early Electronic Music - The Digital Computer as a Musical Instrument Matthews 14:26 - Discovering FM Synthesis 19:25 - The FM Enlightenment 23:14 - Yamaha DX7 31:09 - Synclavier VS Yamaha 36:02 - FM Made Simple 43:04 - The Power of Timbre - MaxMSP "Max" 51:09 - Where are we now?
DX-7 II + add on: Grey Matter E!
I had one of these synthesizers. After adding on a small PCB (Grey Matter E! ?, YouTube, Link to one of sale) the capabilities were greatly increased and not only could it be controlled by my Radio Shack Color Computer it also could remember an arrangement. I think it had a complex rendition of "The Entertainer" built-in. If you know the maker and/or model number of this add on board let me know.
Wave of the Future - History of Chowning's development.
With the introduction of micro controllers and home computers the age of digital sampling (Wiki) allowed the production of sound that matched that of an actual instrument. The samples could be played back at different speeds and modified using the same signal processing methods used for analog music synthesizers. So analog synths fell out of favor and the digital synths took over.
But in the late 1990s an interest in analog synths came back. Part of this is related to the availability of Eurorack (Wiki: Doepfer_A-100)modules, most of which are reasonably priced. PAiA (home, Wiki) has been making low cost music synth modules since 1967 and still offers them.
Yamaha TX802
Is a keyless rack mount box version of the DX7. Requires external MIDI controller.
YouTube: Yamaha TX802 Demo - Yamaha TX802 - A few performance patches -
Dave Benson's DX7 Page - many documents
YouTube, cellarseer: Yamaha TX802 Service Mode - walks through the 8+9+On mode.
YouTube: Yamaha TX802 - A few performance patches, 11:37, 2015 -
Fig 1
Hold number pad 8 and 9 while turning on power.
Firmware V1.0 22-APR-87
Fig 2 Op Sys chip in upper right
just below TX802, marked: XB223 [8]
New chip marked: TX802, XB224 OS V 1.5
-------My ERROR------
I installed the V1.5 chip at the top left, but it should have been
installed in the upper left.
Fig 3 with Ver 1.5 op sys:
The top LCD row is all black dots.
-------My ERROR------
Speakers
Yahama MS101 II Monitor Speaker
Got this to go with the Korg M-20, but also used it with the Yamaha DX-7 (borrowed) and TX802.
Fig 1
Fig 2
MyAmp
eBay search term: "MyAMP" or "Retro Replica Guitar Amplifier High Fidelity/My Amp Audio Portable Speaker K2E9" Under $25 inc shipping.
This is a hand held unit that can be powered either by three AA batteries or by a USB-A to USB-A cable that's included. It's a mono amp, but comes with a stereo 3.5mm - stereo 3.5mm cable.
I got this as an alternative to the Radio Shack 277-1008.
The box has the word "Bluetooth" but that's marketing hype. Also note the brown and Black wires from the USB socket to the main board means that only DC from the USB is supported, not audio.
The speaker seems much more substantial than what I remember of the Radio Shack 277-1008, so this may sound better.
Input Connector:
100k Ohms Left to ground
100k Ohms Right to ground
20k Ohms Left to Right
Fig 1 This is very small, fits in hand.
Fig 2
Radio Shack 277-1008 200 mW
I'm hoping to use this "MyAmp" as a replacement for the Radio Shack 277-1008.
Note The new version 277-1008 has a Positive center 9VDC input. It runs on 9V (battery or external wall wart) and has 3.5mm input and ext speaker/headphones output jacks.
The prior 277-1008 Micro-Sonic unit runs only on a 9VDC battery (no external 9VDC input). Also there is no headphone/speaker output. (See: Radio Museum: Microsonic)
A similar unit was the Telephone Hearing Assist Amplifier Archer 43-229 that ran on a single 1.5 V "N" cell.
K4CHE - Knock Off BC-611 - Schematic of the 277-1008C -
16 - 300 Ohm Headphone Amplifier
eBay title: Portable HiFi Headphone Amplifier Amp 3.5mm Headset Amplifier Two-Stage GAIN - less than $15 including shipping.
Comes with USB-A to USB-C charging cable and double ended 3.5mm stereo plug cable, i.e. cell phone to amp input.
Roland Cube 15x
Found this on eBay for a good price. Poor packaging, but these seem to be made to take a beating and keep on ticking.
First saw this in video: juzzie smith one man band, 5:49 - I'm guessing he is using a car battery and an inverter to get the 120 VAC to power a pair of these amplified speakers.
Roland Support - manual
Fig 1 Styrofoam peanuts (crushed) and popped
air pillows inside box, should have used bubble wrap.
See Packing for shipment.
Fig 2 Front
Fig 3 Back Controls are for Guitar effects (Wiki)
PAM8610 Stereo PCB + Small Speakers
I started by looking at the PCBs based on the PAM8403 (datasheet.pdf) These are nice and run from 5.0 VDC max, or 3ea Alkaline batteries or a single 18650 cell. Some come with a volume pot built-in. There is also a PAM8406 and PAM8610
For lowest harmonic distortion many of the PAM amplifiers like 8 Ohm speakers better than 4 Ohm speakers, but the 4 Ohm speakers offer twice the power.
Model
On
Order
# Chan
Watt/chan
Vmax
PAM8008
2
3
5.5
PAM8012
1
3
5.5
PAM8013
1
3
5.5
PAM8019
2
3
5.5
PAM8302A
large holes on left
for mounting PCB
or 3.5mm terminal block
4
1
2.5
5.5
PAM8945
1
3
5.2
PAM8304
1
3
6.0
PAM8403: Obsolete
2
2
3
5.0
PAM8406 2
2
5
5.5
PAM8610: obsolete
2
2
10
12
PAM8106
2
15
15
50k pot + knob
10
2.5" 4 Ohm
10-20W
Spkr
4
4" 8 Ohm 10W Spkr
3.3" 8 Ohm, 30 Watt (50W Max) Visaton FR 8 M
100 - 20,000 Hz
Parameters
Speakers from Marlin P. Jones
Item #
Description
Mfg
14618 SP 4 Ohm Mini Speaker- 2" 4 Ohm, 400 - 8k
Gento P/N ZSP99023A 33056 SP 8 Ohm Mini Speaker, 3W, 2in. - 2" 8 Ohm 3W
33055 SP 4 Ohm, 3W, 2in. Mini Speaker- 2" 4 Ohm 3W
35607 SP 2-3/8" 8 Ohm MINI SPEAKER - 2-3/8" 8 Ohm 20W
Onkyo 580213-1001 36939 SP Pack of 6 - Multi Sized Micro Speakers Speaker small horn - 8 Ohm 1W
HiFi Audio Design: Measurement - Calculators -
Theremin (Wiki) (my Geek Stuff page)
He's the father of electronic music. That's to say he made the first electronic music instrument. Moog (Wiki) designed a number of Theremins starting in high school. The Beach Boys (Wiki) used a Tannerin (Wiki) (easier to use than the Theremin), for Good Vibrations. PAiA and Korg make Theremins.
TED Talks: Pamelia Kurstin plays the theremin - her's is a left handed unit, i.e. she uses her left hand for pitch control. She makes the point that when playing you must keep your body very still, even to the point of not breathing during a low note.
The problem is most people can not move their hand to a fixed position in 3D space and hold it there, so it's a difficult instrument to master.
Linnstrument
This introduced me to expressive music controllers. Each key is sensitive for pressure (Z axis), pitch bend (x axis) and a third parameter like filter setting (y axis) allowing for very nuanced performance.
There are a number of other expressive controllers such as:
The Eigenharp family of instruments (Wiki) from EigenLabs - patent 8934088 Sound-creation interface - uses a custom switch that has variable outputs for x, y and z based on modulating a light beam or using a breath controller.
These allow performing electronic instruments with the same expression as actual instruments, fantastic!
Roger Linn - LinnStrument Introduction, 8:45 -
Yamaha CSF-TA Guitar
At first glance this appears to be an acoustic guitar. But it has an internal DSP based (Wiki) processor that adds special effects then used a force actuator to shake the sound board so it acts as a loudspeaker.
7812243 Stringed instrument with embedded DSP modeling for modeling acoustic stringed instruments, Peter J. Celi,Michel A. Doidic, Marcus Ryle, Yamaha Guitar Group Inc, 2010-10-12 - The actuator might make use of
Magnetostrictive material, i.e. be something like the Sound Bug.
DATS V3 Audio Test System
Made by Dayton Audio - DATS Ver 3 - DMK-1 Delta Mass Scale and Weight Kit for DATS.
This is a two terminal audio test system. One of it's strong suits is measuring precise Thiele/Small parameters (Wiki).
1869178 Sound translating device, Albert L Thuras, Bell Labs, 1932-07-26, - closed box with port - Shows an electrical equivalent circuit of mechanical speaker and enclosure.
I have a book that goes into this that I purchased to learn more about Sonobuoys. Also see GR Sound Equipment.
Related
Korg MS-20 Mini Synthesizer
While looking for an analog music synthesizer that might be used with the Linnstrument came across the 1978 MS-20 (Wiki) and the modern MS-20 Mini version that includes MIDI (Wiki).
Note that the M-20 is a monophonic (one note at a time) synth and so is not suitable for use with the Linnstrument.
Korg SQ-1 Analog Sequencer
Pocket Operators
by Teenage Engineering PO-16 Factory "lead synthesizer for keys melodies. sequencer with parameter locks, play styles and punch-in effects. pocket operators are small, ultra portable music devices." - User Guide - pdf -
Fig 1
Very capable device, but has a steep learning curve.
YouTube TE: pocket operator tutorials (9 videos) PO-16 Factory, 8:07 -
Note there are LEDs above each button 2 and 12 are on in this photo.
YouTube: Teenage Engineering : Field System:
Teenage Engineering: TP-7 Recorder, CM-15 Mike, TX-6 Mixer, Field Accordion bag - Son Wu -
Book: Push Turn Move -
YouTube: Teenage Engineering Pocket Operator PO-16 Factory - Demo & Tutorial, 10:54 -
PO-14 Plays Any Note! (Works on PO-16 Too), 8:56 -
Using PO-16 FACTORY from Teenage Engineering , complete in depth guide tutorial, 32:37 -
Gecho Loopsynth
DIY Synthesizer
Home Theater - 7.1 Surround Sound
Sound Powered Telephones & Early Loudspeakers
Audio
Pneumatic Operated Instruments
The Player Piano (Wiki)
Patents by Kenneth B. Caulkins related to this topic.
eBay: user: kenquienenquien -
Ragtime Automated Music - Catalog.pdf
Links
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Page created 22 June 2003.