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[Stan]

I have just found a DIY sound system that was published in a long gone magazine. The circuit was published way back in 1992 and you had to draw all the art work; make your own P C B;  drill out all the holes; source all the components and then solder them into the board. If you were lucky you got some type of sound or total silence and on the odd occasion a puff of smoke followed by a burning smell. The circuit in the picture is a multi cylinder diesel and if you manged to get one working you felt the bees knees! The process of making the circuit board involved some very strong chemicals, an etching tank and a U V light box which have all now gone to the tip. Along with sound systems various other circuits were published such as flashing lights, amplifiers and fog horns to name a few. I will see if I have any more home built units and post
some more pictures.


Stan. then. Now [size=78%]  [/size]

[john44]

That’s a blast from the past Stan.  Thank goodness for micro electronics, and actual engine recordings being available.
I never had a burnout on any of my diy circuits 


John

[ddmckee54]

I see the 555's that allowed you to generate several different frequencies, what were you using for a mixer and/or amplifier to drive the speaker?


I don't remember a 555 being able to source enough power to drive a speaker. (But that integrated circuits course WAS over 30+ years ago.)

 
Don

[Stan]

Sorry the unit was connected to external amp. One thing for certain next stop for them the tip. These circuits are are 29 years old hitec then scrap now.




Stan

[ddmckee54]

Stan:


I know what you mean.


For fun I was working on the design for a model railroad digital command control system at about that same time.  As you say high-tech then, pitifully crude now.  It would have worked though, it was based on lab-work we did in that same integrated circuits course.


Don

[Stan]

Hi Don 29 years ago there was nothing else has you know. Maybe in 30 years time even less the units we use today will be crude just like the picture above. It is quite possible in 30 years I will not be about around to compare ha ha .


Stan

[malcolmfrary]

For home made ones I think a tipping point was around 2002 when Maplin started selling sound recording chips which let you store a sample of a recording and play it back.  Of course, shortly after they were found to be useful, they discontinued them as was Maplin's unfortunate habit.  But there also appeared greeting card chips.  A fraction of the size and cost of the ISD series of chips, and already mounted on their own board, just needing an amplifier to drive a speaker and something to switch them on.


The 555s were amazingly versatile, and did have a 200mA output pin, but it was just switched on or off, not really an audio source.  The on-off nature of the outputs needed a conditioning circuit to turn it into a useful waveform ready for amplifying, which is what I suspect most of the bits on Stans board were doing.

[C-3PO]

Then...





Now -

On my desk under development - 32bit 96khz digital stereo DAC loveliness



C-3PO

[Plastic - RIP]

I see the 555's that allowed you to generate several different frequencies, what were you using for a mixer and/or amplifier to drive the speaker?
I don't remember a 555 being able to source enough power to drive a speaker. (But that integrated circuits course WAS over 30+ years ago.)
Don

Some versions of the 555 could deliver about 1A - plenty to drive a speaker directly.

[C-3PO]

Sound thingy has become a bit of an obsession...





C-3PO

[Martin (Admin)]

 .... is it waterproof yet?   

[C-3PO]

 .... is it waterproof yet?   

Hmmmm - however it does make the hairs on the back of your neck stand up - just awesome, full on, rich sound.....

I never realised that playing by numbers could be so much fun... - the snippet of the sound file below is 82,000 lines long

C-3PO

Code: [Select]

5249 4646 1c30 1400 5741 5645 666d 7420
1000 0000 0100 0100 2256 0000 44ac 0000
0200 1000 6461 7461 f82f 1400 1000 1000
1000 1000 1000 1000 1100 0f00 1000 0f00
0f00 0e00 1000 0f00 0f00 0f00 0f00 1100
0f00 1000 0e00 0f00 0f00 1100 1100 1000
0d00 0d00 0f00 1200 1200 0f00 0e00 0f00
1000 1000 0f00 1000 0f00 0f00 0f00 0e00
1000 1000 0f00 0e00 0f00 1000 1000 1000
1000 1000 1000 1000 1000 1000 1200 1100
1200 1100 1100 1100 1200 1100 1100 1100
1100 1000 1100 1000 1100 1000 1100 1100
1100 1100 1000 1100 1100 1200 1100 1100
1100 1200 1000 1200 1000 1100 1000 1000
1100 1100 1100 1000 1000 1100 1100 1100
1000 1100 1100 1100 1100 1100 1000 1000
0f00 1000 0f00 1100 1000 1000 1100 1100
1000 1100 1000 1000 0f00 1000 0f00 1100
1000 1000 1000 1000 0f00 0f00 0f00 1000
1000 1000 0f00 1000 1100 1000 0f00 0e00
0e00 0e00 0f00 0f00 0f00 1000 1000 0f00
0f00 1000 0f00 1000 1000 0f00 1000 0f00
1000 1000 1000 1000 0f00 0f00 0f00 1000
0f00 0e00 1100 1000 1000 1100 0f00 1000
1000 1000 1100 0f00 1000 1000 0f00 0f00
1000 0f00 1000 0f00 1000 0f00 0f00 1000
1000 1100 1100 1000 1000 1200 1200 1100
1100 1000 1200 1100 1000 1200 1200 1100
1100 1100 1200 1300 1200 1300 1100 1000
1300 1500 1400 1100 0e00 0f00 1200 1400
1300 1100 1100 1100 1100 1100 1200 1200
1100 1100 1200 1100 1200 1200 1200 1100
1000 1100 1200 1100 1000 1100 1000 1100
1000 1100 1100 1100 1000 1100 1000 1100
1100 1000 1100 1000 1100 1100 1000 1000
1100 1100 1100 1100 1000 1100 1000 1000
1000 1000 1000 1000 1000 1000 0f00 1000
1000 1100 1000 1100 1000 0f00 1000 1000
1000 1000 1000 1000 1000 1000 1000 1000
1000 1200 1100 1000 1100 1100 1000 1100
1100 1000 1000 0f00 1100 1100 1100 1000
0f00 1000 0f00 1100 1000 1000 1000 1000
0f00 1000 1100 1100 0f00 1000 1100 1100
1100 1100 1100 1000 1100 1100 1000 1100
1100 1000 1000 1000 0f00 1000 0f00 1000
1000 1000 0f00 1000 0f00 0e00 1000 1100
1000 1000 1000 1000 0f00 1100 1000 1000
1000 1000 0f00 1000 0f00 1000 0f00 1000
1000 1000 1000 1000 1000 1000 1000 1000
1100 1100 1000 1000 0f00 1100 1100 1100

[ddmckee54]

I'm not that fluent in hexadecimal, what's it say?


Don

[C-3PO]

"Work in progress"

Sounds way better on my desk - single engine proportional sound

A fair bit of DSP work required to create a decent start and stop sound...

https://soundcloud.com/user-477761400/a-1

and first attempt at twin engine - sorry about the ending :)

https://soundcloud.com/user-477761400/model-boat-twin-engine

Regards
C-3PO