Picture of Robot Voice Modulator
This is a simple to build device that converts your own human voice into a superior robot voice. It also includes a number of sweet features like an audio-in jack so that you can plug in all of your favorite instruments, microphones and music players, a vibrato mode and awesome pitch shifting buttons. It can be shifted two whole octaves in either direction. This provides for endless hours of fun (at the expense of everyone around you).

To here some crazy robot and pitch shifting action check out the file posted below.
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Step 1: Go get stuff

Picture of Go get stuff
You will need:

- And IKEA clock body
- An adjustable fluorescent desk lamp
- A HT8950 voice modulator
- An 18-pin socket
- 4 SPST buttons
- Condenser mic
- Parts for the circuit (see next step for details)
- Wire
- 2 1/8" audio jacks
- A power source
- Misc hardware

Step 2: The circuit

Picture of The circuit
Breadboard the "HT8950 with a Transistor Output Stage and a 6V Power Supply" circuit found in the official data sheet minus the transistor output stage. Instead, wire that to an audio out jack.

Then solder the circuit onto a PCB, temporarily omitting things like the microphone, audio jacks and switches. This will be added later.

You can test to make sure the board works by adding extra hookup wires for the audio jacks and microphone and connecting them through a breadboard.

Step 3: Get bendy arm

Picture of Get bendy arm
Take apart your fluorescent desk lamp and remove the nifty bend arm.

Don't remove the lamp wire from inside the arm. You will need this to hook up your microphone. Therefore, don't trim it too close.

Leave the mounting bracket still attached at the bottom of the arm.

Step 4: Bracket stencil

Picture of Bracket stencil
Cut out a bracket stencil using the attached file.

If you happen to have an awesome Epilog laser cutter like we do at Instructables than you can use that to cut out the pattern onto a piece of tape. If you don't, an Exacto knife will do.

Place this pattern onto what you feel will be the back edge of the robot voice machine.

Drill out all of the holes with a power drill.
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SIR can we have a copy of your circuit diagram of this project

Bmrshoot4 months ago
Building a transformer costume for my son, will this make his voice sound like a transformer....iron hide specifically.
gluvit1 year ago
Good stuff
LoSkana1 year ago
Ehm... the data sheet is now not available ^^
The chip and the Datasheet is available at
JSWheeler1 year ago
The "data sheet" link is giving me an error.
synthdust2 years ago
Looks like he has two different circuits on that bread board. That little 8 pin IC is missing from the strip board... I think.
*perf board.
is this expensive?????????
Darn I dont have one of those chips. Mabey Marvin will loan me his space modulator, and I can use that...
Akash.C.A3 years ago
Where is the circuit diagram......?
I´m trying to build the Voice Modulator and I´ll thank you if you tell me which microphone did you use.
Thanks a lot
randofo (author)  gbarbadillo villanueva3 years ago
Could you work this into a synth oscillator?
I don't see why not, just replace the micro phone with the synths output.
And don't forget to hook the black wire of the mic to ground.

Ps. Did you make your own synth?
monsterman4 years ago
do yo remove the 200 ohm pot
oweng40004 years ago
That mp3 was hilarious
Volgon4 years ago
Where did you get the chip from? i checked all the usual places (radioshack, amazon, Frys) and i cant find it anywhere.
randofo (author)  Volgon4 years ago
Ebay. I got 10 for about $20.
Malccc4 years ago
hey,thank you very much!Im gonna give it a try~!
youn_link4 years ago
Can you pass the diagram circuit?
srmousse4 years ago
You get points for functionality and style!!! =)
mdnahid944 years ago
Please give me circuit diagram. Becoz I can try this.....
tinsolder4 years ago
if you'r too lazy to breadboard etc... check out for a Velleman mini-kit (MK171). Its also funny to bend it. and you can also use it for a stomp box.
SinAmos4 years ago
A HT8950 voice modulator chip. :( I thought you were going to do it electronically/mechanically.
codyduncan4 years ago
 What's going on on that board?  I see an extra IC and what looks like a transistor.

I'm thinking your "they can figure it out" scheme may not be the best policy.  I am trying to build this right now, but I am trying to avoid building it and finding that it doesn't work without  this or that extra component.

If you did add extra parts (it looks as though you did) what were they for?
SGplayer5 years ago
Foaly75 years ago
How big is this thing?
randofo (author)  Foaly75 years ago
About the size of a wall clock or stuffed owl. The circuit is pretty small. The casing can be miniaturized.
Foaly7 randofo5 years ago
Ok, and can you make the microphone attached to a cord that can be ran up, say, a jacket sleeve? I suppose you could, but how?
RPisces5 years ago
I have that same laptop lol
helios125 years ago
How much did all the parts cost?
~BINGO~ That's exactly -eh, what I was looking at... Now as I read through the threads (how could I miss it...?) it's all clear now. Thanks
you have a transistor; not listed in your 'to get' list... Wold be nice to know~
randofo (author)  Arnoldofingo5 years ago
No I don't. Maybe you are looking at the 7805 voltage regulator.
bgirlrox175 years ago
I love the idea
amplex5 years ago
i bought 3 off ebay for <$10 less than a year ago. ive had one sitting on a breadboard for 8 months and still havent put it on perfboard, even though this is a really cool bendable 8bit modulator =( maybe ill finally do it today
sourcery5 years ago
Maybe you could download DIY Layout Creator and draw a nice circuit diagram for this circuit. It would be easier to follow instructions that way ;)
randofo (author)  sourcery5 years ago
I normally include schematics, but didn't see much point in redrawing something that could be found on the data sheet. There are only a few minor changes which are easy to figure out (such as the SPDT toggle switch between the mic and audio in and the audio out jack instead of the amplifier stage).
Ok, it was just a suggestion... I have started to use the program (DIY Layout Creator), and it is quite useful for experiment board projects :) Now I just need to find the HT8950 chip in Sweden :)
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