Aliab posted images along with schematics of the latest voice bending project which involves a simple transistor preamp and an simple Octave Up circuit found on DIYStompBoxes.com.
The two separate circuits were then connected together and crammed inside of a gas mask canister, definatelly not for the weak of heart or breath.
Sound sample is located here.
How could you modify this to work in the more common M-17 gas mask?
you could probably fabricate some custom PCB’s for each component to reduce the size and then house one in each side of the mask. i’ve never handled an M-17, but from what i’ve looked at online, it seems to have a lot more room in the muzzle than my mask. this would probably give you more options in terms of placing the components.
Don;t forget, you could jput the microphone in, and have the wire come out into an external box/strapped on device.
Here is a link to the sound clip: http://asiliveandbreathe.net/gasmask.html
Sounds like shit
What are the specs for the transformer on the octave up? I cant read the handwriting, sorry
Another way to do this but a little more complicated is to use 2 chips.
A (NE602AN balanced modulator) and a (Icl8038 sinewave function generator).
A small preamp feed the mic into the NE602AN.
A sinewave from the ICL8038 14 pin dip is fed into the NE602AN 8 pin dip.
The 2 signals heterodyne causing a phase shift in the voice.
You can ajust for any sound you want by changing the freq from the ICL8038.
There was another better chip i tinkered with back in 1992 made by sterling electronics.
It was an all in one chip all it required was a 4.00 Mhz color burst crystal from a color tv to work and a final amp (LM386) 8 pin dip.
It had an 8 bit DAC built right into it and could it change your voice.
The chip reqired a split power supply of 5+ volts for digital in and analog in.
If i find the part number i’ll post it here.
That chip would be your best bet.
Output voice was SMOOOOOOOTH not scratchy.
Interesting thanks for the info Ezight. Let me know if you locate the chip ID.
Ok found it.This the link to a small site with a pdf on it.
Ive opened it and it is clean using AntiVir PE Classic.
http://www.chipdocs.com/pndecoder/datasheets/OKI/MSM6322.html
This is the chip i played with in 92,it was highly ahead of it’s time back then.
Ever watch those shows where they mask a persons voice?
This was the cats meow as far as voice changers.
You need experience soldering surface mount IC’s.
The pins are very very close togeather.
Might want to use a sewing needle iron for it.
But with this and a little audio amp like a lm386 you can have alot of fun.
The chip has all you need except for clock (the 4 Mhz colorburst crystal from an old TV or you can buy one for 99 cents at RadioShaft ,—-lol.
The MSM6322 was quite a chip, i hear alot of the high end voice changers sold on the web ready to go have this chip in it.
Back when i was messing with it it was for companies that made Radio station and studio consoles.
You know (studio ) special effects consoles for Movie studios and whatnot.
Anyway have fun.
The mixer i mentioned above can do really weird stuff like double sideband effects that be used for audio encryption. not to secure though it’s been around for like 40 years.
Either way makes for some interesting effects, Have fun.
Wow, real-time pitch control thats serious fun waiting to be had. I wonder if the same technology was used in the Rapman because that has a pitch shifter. Give the OKI – Casio partnership I would not be surprised.
I haven’t found these chips for same anywhere yet, but thats not to say that there are no boxes of them waiting in storage at some Chinese factory.
Check this out http://cba.sakura.ne.jp/kit01/kit_074.htm , voice changing kit from Japan with the chip. Thanks for the info Ezight!
On that first circuit i mentioned (Ne602an) That a gilbert cell mixer.
It takes 2 signals -your voice- and a tone (Sinewave)
and makes the sum and the difference of the 2.
you end up with what sounds like sideband on a CB radio.
A tweak of the sinewave generator your voice goes up or down.
I might add that the SA602AN was it’s replacement.
It rejected the OSC more so you did not have to lowpass or high pass the output of the mixer (it was better).
Any hoo.
If you have one of those new FRS radios that have the encryption option.
Well lets just say tha SA602AN and the NE602AN can —well cough—(undue that sqibly duck quacking gibberish you hear when 2 FRS radios are um(Running in that mode)
Its really old technology they use to do that.
When they first came out was was shocked that they were using
(Double sideband) to talk private with.
Being they are FM and they used that gimmick shocked me.
All you need to undue that is a mixer NE602an,a sine wave generator or another radio of the same caliber.
Anyway………….You will all learn cool junk while playing with theese 4 chips i mentioned.
PS
read the tech specs and get the PDF files on each chip.
They have example circuits to go by and if your good at it, it’s no problem breadboarding and taking it finished product.
it’s all gone now…
Use a Ring Modulator