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Thursday, December 24, 2015

Homemade Darth Vader Voice Changer 2.0 (work in progress)

Introduction

The last couple of weeks I worked on a homemade voice modulator that is easy and cheap to built. First I'd like to mimic the Darth Vader Voice Changer, but with the press of a button it can be changed to robot or helium kind of voice effects. Last week I've steadily continued my work. The project has two main parts, the electronics and the case.

Electronic circuit

For the project I choose the HT8950A voice modulator from Holtek as the heart of the circuit. It is cheap, versatile and easy to work with. I previously had the voice modulator working. I only had to amplify the signal which seemed simple enough. Well, that turned out to be a bit more troublesome than expected. After connecting the LM386 to the circuit and powering it up an annoying hiss was introduced. After some experimenting I figured that the breadboard was to blame and decided to copy the circuit to another breadboard. Although on the new breadboard the hiss appeared somewhat reduced but it was still at an unacceptable level. Even when I removed the input signal from the LM386 the hiss continued. I connected the HT8950A with a audio-jack to an external amp. I wanted to make sure that the hiss was coming from the LM386. With the external amp the hiss was gone. The fact that I had hiss without an input signal indicated that the supplied voltage wasn't clean.  To clean it up I placed a small capacitor (10nF) from pin 6 (V+) to ground and voila the hiss was gone (see schematics below). It took me some time but I'm almost ready to finish this circuit and solder it to perfboard.

Two (almost identical circuits) with the Holtek HT8950A voice modulator and the LM386 amplifier. Both circuits gave a hiss which was unacceptable. Eventually a simple 10uF capacitor from pin 6 to ground did the trick for me. 
Schematics of the Darth Vader voice changer. I was able to eliminate all the hiss and noise from the LM386.

Printing the case.

I decided previously to make a T-slot plywood case for the Voice Changer but I'm not satisfied with the result. First I made a beginners mistake with the tab width. It was chosen poorly resulting in fragile edges of the case. Also I discovered that a T-slot case is not the best choice for this project. The case needs to be sturdy and the T-slot isn't. I'm afraid it will fall apart when in use. Therefore I'll made a regular finger joint that will be glued together. This new case was much better. Gone are the fragile edges and I'm confident that glued together it will be very sturdy.

Laser cut case made out of plywood. I first used a T-slot type of case but made a beginners mistake with the tab width and positioning. As a consequence the edges become very fragile. The front of the case has engravings for the positioning of large controls of the voice changer. These controls on the front will we dummies just to mimic the look of a Darth Vader voice changer. The actual controls will be on the side of the box.
Laser cut case with regular finger joint. This attempt is much better.

14 comments:

  1. I have a kylo ten voice changer.
    It doesn't sound the best and I want to fix it somehow.
    Here's the link to my product

    http://vi.raptor.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=181874233215&category=2622&pm=1&ds=0&t=1461685677244

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    Replies
    1. I think the Kylo Ren voice can be done with the HT8950A (just a one step higher pitch than Darth Vader). I suggest you swap current the electronics board for the DIY board shown above provided you have enough space. You do need to have some experience with electronics. Alternatively you could buy the MK171 Velleman kit which is easy to assemble and contains the HT8950A chip.

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    2. If I'm going to buy another voice changer (HT8950A) (MK171 Velleman kit)
      These have to work. I can't buy something that won't work.

      But anyways,
      Mr. Eric
      Can you check out this video on youtube . This man made an AWESOME!! KYlo ren voice changer. He's going to make a follow up vid on how he did it but I want to know now.
      Here's the link.

      https://youtu.be/6JfLOIlGqHU

      This is the best one out there and I want to make one just like his. Do you know how he did it? Also,
      I'm a noon when it comes to voice changers. Id like to learn about how they work. And buy the best one for a kylo ten voice.

      Thank you

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    3. He basically upgraded the crappy toy helmet by replacing the machinery with new parts. He said it cost about 50$ worth of new material.

      I want to know how he did it so much.

      I'm also thinking about a general grevious voice changer too.

      Delete
    4. Hi Ron, I've seen the YouTube video and it sound pretty convincing. Jinx117 tells that he removed the microphone, speaker and logic board (I assume the're all crap) and inserted new components. Unfortunately he doesn't tell which components he used. I dropped a comment and hopefully we get a reply.

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  2. Ron if you want to learn about voice changers and eventually make them I'll advice to first follow a practical electronics course. If you already have forget my advice but if you haven't Make Electronics (http://www.makershed.com/products/make-electronics-2ed) from Charles Platt is a excellent start.

    ReplyDelete
    Replies
    1. I'll definitely look into it.

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    2. https://learn.adafruit.com/wave-shield-voice-changer

      Thinking of getting this product

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    3. Can't argue with that, Adafruit makes first class products and their project descriptions are excellent. I'll take a good look at this project myself.

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  3. Sir, if I may ask.
    In the schematics above I see a potentiometer labeled 250. Is it 250 ohms or 250K ohms?

    ReplyDelete
  4. hy im new to electronics and i was wondering if that is the final scheme on the project and wanted to know if those were all the parts i need so i can buy them.
    Thank you

    ReplyDelete
    Replies
    1. Apologies for my late reply. It has been rather hectic the last couple of weeks. Anyway I've written an overview of this project that can be found at http://eribuijs.blogspot.nl/2016/01/darth-vader-chest-box-finished.html. This blog post also contains the latest schematics. Most components are generic and can be bought online or at your local electronics shop. The one exception is the HT8950A chip. This chip can be bought from Alibaba or EBay.Good luck.

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