DIY - Elektor Vocoder - General Build Thread

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: Kent, luketeaford, Joe., lisa

Post Reply
User avatar
Fitchie
Wiggling with Experience
Posts: 337
Joined: Sun Aug 30, 2015 1:49 pm

Re: DIY - Elektor Vocoder - General Build Thread

Post by Fitchie » Thu Oct 01, 2020 3:20 am

nologin wrote:
Wed Apr 29, 2020 2:27 pm
Hello, there are 2 resistors that i don't see in the BOM. R42 on the switching board and R36 on the highpass board.
Please download the confirmed BOM here:
http://www.vocoder.eu/vocoder-bom.xlsx

User avatar
Fitchie
Wiggling with Experience
Posts: 337
Joined: Sun Aug 30, 2015 1:49 pm

Re: DIY - Elektor Vocoder - General Build Thread

Post by Fitchie » Thu Oct 01, 2020 3:32 am

bluestang wrote:
Sat Apr 25, 2020 5:36 pm
Is the kit still available for purchase?
I have put together a new batch of 10 kits.
All 10 kits are available now and can be ordered at http://vocoder.eu/online-shop.html still at the old price.

First in first out...

User avatar
zephyrin
Common Wiggler
Posts: 67
Joined: Sun Apr 17, 2016 2:15 am
Location: Lausanne

Re: DIY - Elektor Vocoder - General Build Thread

Post by zephyrin » Thu Oct 01, 2020 7:17 am

Finaly I have fixed all my issue with filter board:
For one I have a bad wiring, for an other the swith of the mini jack is alway open, for an other I m certainly a bad solder but I don't found where.
I have change all restor and capacitor of the carrier's filter fixed the issue.
For the high pass filter i have used 33nf film capacitor instead of 33PF ceramic .

All filter works fine but that I have say for me it's impossible to see the signal at the pin 6 of 741 I m using an hardware scope ( Owon SDS7072E 70 MHz)

User avatar
Fitchie
Wiggling with Experience
Posts: 337
Joined: Sun Aug 30, 2015 1:49 pm

Re: DIY - Elektor Vocoder - General Build Thread

Post by Fitchie » Fri Oct 02, 2020 8:42 am

I made a simulation of what you should "see" on the oscilloscope when probing the outputs of the OpAmps.

FilterPrinciple.jpg

And these are real scope images where you see the audio input signal in blue and the envolope (output A9 - pin 6 of LM741) in yellow.

Envelope.jpg

So if you don't see anything on A9, that simply means the specific filter doesn't work.
You do not have the required permissions to view the files attached to this post.
Last edited by Fitchie on Fri Oct 02, 2020 4:38 pm, edited 1 time in total.

User avatar
elmegil
Super Deluxe Wiggler
Posts: 3007
Joined: Sun Apr 29, 2012 2:57 pm
Location: Chicago

Re: DIY - Elektor Vocoder - General Build Thread

Post by elmegil » Fri Oct 02, 2020 9:42 am

@Fitchie, those images don't appear to be working right now?

User avatar
Fitchie
Wiggling with Experience
Posts: 337
Joined: Sun Aug 30, 2015 1:49 pm

Re: DIY - Elektor Vocoder - General Build Thread

Post by Fitchie » Fri Oct 02, 2020 4:21 pm

elmegil wrote:
Fri Oct 02, 2020 9:42 am
@Fitchie, those images don't appear to be working right now?
Mmm... Strange... I can see them clearly.

Try these links:
http://www.vocoder.eu/docs/FilterPrinciple.jpg
http://www.vocoder.eu/docs/Envelope.jpg

User avatar
elmegil
Super Deluxe Wiggler
Posts: 3007
Joined: Sun Apr 29, 2012 2:57 pm
Location: Chicago

Re: DIY - Elektor Vocoder - General Build Thread

Post by elmegil » Fri Oct 02, 2020 4:26 pm

Fitchie wrote:
Fri Oct 02, 2020 4:21 pm
elmegil wrote:
Fri Oct 02, 2020 9:42 am
@Fitchie, those images don't appear to be working right now?
Mmm... Strange... I can see them clearly.

Try these links:
http://www.vocoder.eu/docs/FilterPrinciple.jpg
http://www.vocoder.eu/docs/Envelope.jpg

I suspect it may be something about permissions somewhere along the way? The links do work fine. But here on Muff's this is what I see:
Screen Shot 2020-10-02 at Oct 2 4.24.28PM.png
You do not have the required permissions to view the files attached to this post.

User avatar
Fitchie
Wiggling with Experience
Posts: 337
Joined: Sun Aug 30, 2015 1:49 pm

Re: DIY - Elektor Vocoder - General Build Thread

Post by Fitchie » Fri Oct 02, 2020 4:39 pm

elmegil wrote:
Fri Oct 02, 2020 4:26 pm
I suspect it may be something about permissions somewhere along the way?

Original message edited.
Can you see the pictures now?

User avatar
elmegil
Super Deluxe Wiggler
Posts: 3007
Joined: Sun Apr 29, 2012 2:57 pm
Location: Chicago

Re: DIY - Elektor Vocoder - General Build Thread

Post by elmegil » Fri Oct 02, 2020 4:42 pm

Fitchie wrote:
Fri Oct 02, 2020 4:39 pm
elmegil wrote:
Fri Oct 02, 2020 4:26 pm
I suspect it may be something about permissions somewhere along the way?

Original message edited.
Can you see the pictures now?
yes, thank you!

User avatar
zephyrin
Common Wiggler
Posts: 67
Joined: Sun Apr 17, 2016 2:15 am
Location: Lausanne

Re: DIY - Elektor Vocoder - General Build Thread

Post by zephyrin » Thu Oct 08, 2020 10:20 am

All Filter board work because I have a signal on the output of the vocoder with the frequency that the voice signal. I don't know why I don't see the signal perhaps there somethings to set in my shop ...


Now I have a trouble with voider/devoiser section but I don't know how debug this.

I have try to inject in the voice input a sinus signal and change the frequencies to scoop it on A B C of the Detecting interface board , but I don't know if it's a good way ?

One the Switching module board the led don't light.

User avatar
zephyrin
Common Wiggler
Posts: 67
Joined: Sun Apr 17, 2016 2:15 am
Location: Lausanne

Re: DIY - Elektor Vocoder - General Build Thread

Post by zephyrin » Wed Oct 21, 2020 3:50 am

No one can help me with the Detecting interface and the Switching module ?

RadekTymecki
Common Wiggler
Posts: 65
Joined: Fri Apr 12, 2013 4:38 am

Re: DIY - Elektor Vocoder - General Build Thread

Post by RadekTymecki » Tue Oct 27, 2020 3:37 pm

Just a question... Are there any mouser bom so I could order all (or most) required parts in one shot?

User avatar
elmegil
Super Deluxe Wiggler
Posts: 3007
Joined: Sun Apr 29, 2012 2:57 pm
Location: Chicago

Re: DIY - Elektor Vocoder - General Build Thread

Post by elmegil » Tue Oct 27, 2020 5:32 pm

RadekTymecki wrote:
Tue Oct 27, 2020 3:37 pm
Just a question... Are there any mouser bom so I could order all (or most) required parts in one shot?
I posted my mouser BOMs on Sat Jan 12, 2019 11:36 pm. On this thread :).

PS: definitely not all the parts.

User avatar
Fitchie
Wiggling with Experience
Posts: 337
Joined: Sun Aug 30, 2015 1:49 pm

Re: DIY - Elektor Vocoder - General Build Thread

Post by Fitchie » Sun Nov 01, 2020 9:47 am

zephyrin wrote:
Wed Oct 21, 2020 3:50 am
No one can help me with the Detecting interface and the Switching module ?
First try to have a working vocoder in the 'basic configuration' without the voiced/unvoiced option enabled.

To use the vocoder in the 'basic configuration', connect pin G + pin H and on top of that also pin I + pin J. These connections can be made either by wire on the foreseen pins at the right side of the backplane, either by bridging both solder jumpers at the backside of the backplane.

See also here:
http://vocoder.eu/jumper-settings.html

Once the vocoder is fully operational, you can remove the jumper or solder bridge etween pin I + pin J to enable the vocoder in 'sibilance mode'.

First check the clock & noise generator, instructions here:
http://vocoder.eu/noise-generator-test.html

Then perform the switching interface adjustment, instructions here:
http://vocoder.eu/switching-interface.html

User avatar
Fitchie
Wiggling with Experience
Posts: 337
Joined: Sun Aug 30, 2015 1:49 pm

Re: DIY - Elektor Vocoder - General Build Thread

Post by Fitchie » Wed Nov 04, 2020 10:28 am

zephyrin wrote:
Wed Oct 21, 2020 3:50 am
No one can help me with the Detecting interface and the Switching module ?
Another suggestion:
Instead of using your oscilloscope, try some spectrum analyzing software on your computer and connect the input of your audio card to the opamp whose signal you want to inspect.

Software example for OSX:
https://dogparksoftware.com/iSpectrum.html

Software example for Windows:
https://trueaudio.com/rta_abt1.htm

This filter behaviour picture was made by adding noise to the input and probing the output of each filter:
FIlter behaviour.jpg
You do not have the required permissions to view the files attached to this post.

User avatar
Fitchie
Wiggling with Experience
Posts: 337
Joined: Sun Aug 30, 2015 1:49 pm

Re: DIY - Elektor Vocoder - General Build Thread

Post by Fitchie » Fri Nov 06, 2020 3:09 am

Good morning everyone,

I have noticed that the installation and adjustment of the vocoder is a bit complicated for a number of builders.
That is why I am expanding the Assembly & adjustment section with more detailed steps and many more pictures.

If you follow these steps (do not proceed if you encounter a problem), everyone should be able to build the project successfully.

The renewed and expanded section is available here:
http://www.vocoder.eu/assembling-adjustment.html

On a regular basis the corresponding sections are expanded with additional photos and scope dumps.

User avatar
Fitchie
Wiggling with Experience
Posts: 337
Joined: Sun Aug 30, 2015 1:49 pm

Re: DIY - Elektor Vocoder - General Build Thread

Post by Fitchie » Sat Nov 07, 2020 4:03 am

New sections available:

User avatar
zephyrin
Common Wiggler
Posts: 67
Joined: Sun Apr 17, 2016 2:15 am
Location: Lausanne

Re: DIY - Elektor Vocoder - General Build Thread

Post by zephyrin » Sun Nov 08, 2020 5:00 am

Hi Fetchie what do you used for this screen, hardware or soft spectrum analyser ?

Image

User avatar
Fitchie
Wiggling with Experience
Posts: 337
Joined: Sun Aug 30, 2015 1:49 pm

Re: DIY - Elektor Vocoder - General Build Thread

Post by Fitchie » Sun Nov 08, 2020 7:04 am

zephyrin wrote:
Sun Nov 08, 2020 5:00 am
Hi Fetchie what do you used for this screen, hardware or soft spectrum analyser ?
This software:
https://trueaudio.com/rta_abt1.htm

A little more in detail:
  • The spectrum analysis was made in different 10 parts. White noise was presented at the input of the vocoder, an analysis was made of both the carrier output (IC1 pin 7) and the voice output (IC1 pin 1) on each band filter. That's why you see 2 lines per filter.
  • Afterwards, the 10 x 2 images were placed on top of each other, the software has a function to do this in an easy way.
  • The minor differences in peak amplitude are caused by component tolerances. As can be seen, the filters provide a nicely regular division of the audio spectrum.
  • The high pass filter comes in a little too early, but that has already been solved by slightly changing the corresponding capacitor values.
  • The 50 hz hum is also nice to see, it stays neatly below -100 db.

All credits for this analysis are in favour of Boogie.


Schematics:
-
Vocoder Spectrum Analysing.png
You do not have the required permissions to view the files attached to this post.

User avatar
zephyrin
Common Wiggler
Posts: 67
Joined: Sun Apr 17, 2016 2:15 am
Location: Lausanne

Re: DIY - Elektor Vocoder - General Build Thread

Post by zephyrin » Sun Nov 08, 2020 9:06 am

Thank you for your answer Fitchie
what version do you used the Level 4 ?
I have try the free version with a Maya sound card (limited to 20 Khz ) , I have juste a barre graphe not a nice graphics like you.

distapro
Learning to Wiggle
Posts: 2
Joined: Sun Oct 21, 2018 3:15 pm
Location: Belgium

Re: DIY - Elektor Vocoder - General Build Thread

Post by distapro » Sun Nov 08, 2020 10:43 am

Hi,
I began to build this project a while go but I had to put it aside for a while. Recently I started to continue to work on this project again so I went to the web site vocoder.eu.
I was amazed to find the updated information and specially the latest additions. On the website I found a treasure on information that helped me to get on track again.

I think with the information on the website (www.vocoder.eu) it should be possible for an electronics hobbyist, even with moderate experience, to get the job done. It's a lot of soldering and calibration can be challenging if you're not that experienced, but it's not impossible.
The documentation on the website is really fantastically done. Good overview and clear explications of how to do it right, looks and feels very professional.
I ‘m using the suggested parts from the BOM and found al the answers on this website up to now.
Congratulation great work Fitchie. :tu: :tu:

User avatar
Fitchie
Wiggling with Experience
Posts: 337
Joined: Sun Aug 30, 2015 1:49 pm

Re: DIY - Elektor Vocoder - General Build Thread

Post by Fitchie » Sun Nov 08, 2020 1:51 pm

zephyrin wrote:
Sun Nov 08, 2020 9:06 am
what version do you used the Level 4 ?
The $ 99,95 version, I thinks it's level 4.

By the way, Elektor used to make a similar montage in the 80's, old fashioned with negatives and a CRT spectrum analyser.
:love:

Enjoy;
-
Elektor Original Spectrum.png
You do not have the required permissions to view the files attached to this post.

User avatar
zephyrin
Common Wiggler
Posts: 67
Joined: Sun Apr 17, 2016 2:15 am
Location: Lausanne

Re: DIY - Elektor Vocoder - General Build Thread

Post by zephyrin » Sun Nov 08, 2020 2:17 pm

I think to that you have level 4.
I m just buy it, I must wait for having the key because the key is generated manualy.

I have changing C1-C8 for several board because with the scope the V RMs was too different between the carrier output (IC1 pin 7) and the voice output (IC1 pin 1).
The capa are grey color and comes from Tayda

I have swapping them by green Capa, I have selected the same value by pair (C2-C6 C1-C5 C4-C8 C3-C7) ,the result is better.
Each capa has a value close to the ideal value, the difference is less than 5%

I have also notice that different CA3080 influenced the output voltage.
I have try SMD CA3080 and they are not good for the vocoder, when pot of the board is fully to the left, there remains a residual voltage at the output .

User avatar
Fitchie
Wiggling with Experience
Posts: 337
Joined: Sun Aug 30, 2015 1:49 pm

Re: DIY - Elektor Vocoder - General Build Thread

Post by Fitchie » Sun Nov 08, 2020 2:50 pm

zephyrin wrote:
Sun Nov 08, 2020 2:17 pm
The capa are grey color and comes from Tayda.
The capacitors used on the spectrum analysis are all from TDK. Not the cheapest, but I am satisfied with the result.
In another prototype KEMET's & Panasonc's are used.


zephyrin wrote:
Sun Nov 08, 2020 2:17 pm
I have also notice that different CA3080 influenced the output voltage.
I've used some of them randomly with no significant issues, but in one of the prototypes I've built the 741's were picky.


zephyrin wrote:
Sun Nov 08, 2020 2:17 pm
I have try SMD CA3080 and they are not good for the vocoder, when pot of the board is fully to the left, there remains a residual voltage at the output.
The less residual voltage, the better.
But I have to admit that I don't always get it all sorted out completely.

User avatar
zephyrin
Common Wiggler
Posts: 67
Joined: Sun Apr 17, 2016 2:15 am
Location: Lausanne

Re: DIY - Elektor Vocoder - General Build Thread

Post by zephyrin » Mon Nov 09, 2020 2:40 am

Fitchie how do you check the signal? Do you used a scope probe ? Do you have made electronic hardware for protecting your sound card ?

Post Reply

Return to “Music Tech DIY”