Music

Brooke Clarke 2003 - 2021

DX7
TX802
Speakers
    Yahama MS101 II Monitor Speaker
 
    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
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

The DX7 (Wiki) uses a very sophisticated analog mixing scheme to make very complex and pleasant to humans sounds.  It's probably the last of the analog electronic music instruments.

In addition to equal temperament tuning there were other tunings 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.

DX-7 II + add on

I had one of these synthesizers.  After adding on a small PCB (Grey Matter E! ?) 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.

Fig 1
Hold number pad 8 and 9 while turning on power.
Firmware V1.0 22-APR-87
Yamaha TX802
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.

Yamaha TX802
Fig 3 with Ver 1.5 op sys:
The top LCD row is all black dots.
-------My ERROR------
Yamaha TX802


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
Yahama MS101
                    II Monitor Speaker
Fig 2
Yahama MS101
                    II Monitor Speaker

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
MyAmp
Fig 2
MyAmp

Radio Shack 277-1008 200 mW

I'm hoping to use this 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.

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.

Fig 1 Styrofoam peanuts (crushed) and popped
air pillows inside box, should have used bubble wrap.
See Packing for shipment.
Roland Cube
                    15x Speaker
Fig 2 Front
Roland Cube
                    15x Speaker
Fig 3 Back  Controls are for Guitar effects (Wiki)
Roland Cube
                    15x Speaker

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 Audio
                    Amplifier
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
50k pot + knob
10



2.5" 4
                    Ohm 20W Speaker
2.5" 4 Ohm
10-20W
Spkr

4



4" 8 Ohm
                    10W Speaker
4" 8 Ohm 10W Spkr



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: MeasurementCalculators -

Theremin (Wiki) (my Geek Stuff page)

There is an interesting Video about Leon Theremin: Theremin: An Electronic Odyssey 1993 (IMDB, Netflix)
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!

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.

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
Pocket Operators
                    by Teenage Engineering PO-16 Factory

Very capable device, but has a steep learning curve.
Note there are LEDs above each button 2 and 12 are on in this photo.

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

Back to Brooke's: PRC68, Alphanumeric Index of web pagesProducts for Sale, Home page

Page created 22 June 2003.