electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links
Forum with support of Syndicator RSS
 FAQFAQ   CalendarCalendar   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   LinksLinks
 RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in  Chat RoomChat Room 
 Forum index » DIY Hardware and Software » The layout factory
Low parts count zener-inductor waveshaper/modulator
Post new topic   Reply to topic
Page 1 of 1 [16 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
cslammy



Joined: Apr 27, 2018
Posts: 206
Location: USA
Audio files: 1

PostPosted: Thu Oct 11, 2018 12:28 pm    Post subject: Low parts count zener-inductor waveshaper/modulator Reply with quote  Mark this post and the followings unread

Hi there, was messing around on the bench and stumbled on the schemo below. Output goes from a cheap distortion pedal sound to reasonably good balanced modulator effects depending on what you put in.

Stripboarded in about 5 minutes. this is like 8 parts, super super simple.

Anyone else have variations or know of this design in the wild. hard to believe it's new, but for me it was a complete accident. Then again I almost never use inductors for anything except power so new for me anyway.

BTW variation for this design and more detail on my blog:
http://audiodiwhy.blogspot.com/2018/10/discovery-by-accident-super-low-parts.html


8 parts.PNG
 Description:
 Filesize:  1.12 MB
 Viewed:  643 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

8 parts.PNG



_________________
Visit my AUDIODIWHY blog and website
Back to top
View user's profile Send private message Visit poster's website
gabbagabi



Joined: Nov 29, 2008
Posts: 651
Location: Berlin by n8
Audio files: 23

PostPosted: Fri Oct 12, 2018 12:45 pm    Post subject: Reply with quote  Mark this post and the followings unread

any chance to see some scope-shots Input-vs-output?
would be nice, just to get more sense out of it.
Back to top
View user's profile Send private message
cslammy



Joined: Apr 27, 2018
Posts: 206
Location: USA
Audio files: 1

PostPosted: Fri Oct 12, 2018 12:48 pm    Post subject: Reply with quote  Mark this post and the followings unread

I was going to do another blog entry with before and after WAV files, but doing scope shots as well is a great idea. I'll do that too. Thanks for the suggestion.
_________________
Visit my AUDIODIWHY blog and website
Back to top
View user's profile Send private message Visit poster's website
gabbagabi



Joined: Nov 29, 2008
Posts: 651
Location: Berlin by n8
Audio files: 23

PostPosted: Fri Oct 12, 2018 11:59 pm    Post subject: Reply with quote  Mark this post and the followings unread

u could also just open the wav in a audioeditor and screenshot the waveforms there, but Scopies are somehow more elegant.

i understood that it is acting like a RM?
can u may run a test where u feed in the same sine in both signal and carrier in?
This is a special task for an RM, it acts then as a frequenzy-doubler, cos it is performing sinĀ²

the other standard test would be sin&saw, the frequenzy of the one should be an uneven multiply of the other eg 1khz/3khz or 1khz/5khz 1/7 .....
this is to see how it is performig the phase inversion when the carrier is going thru zero, means that the saw is running backward then

Posted Image, might have been reduced in size. Click Image to view fullscreen.

cheers, gabi
Back to top
View user's profile Send private message
cslammy



Joined: Apr 27, 2018
Posts: 206
Location: USA
Audio files: 1

PostPosted: Sun Oct 14, 2018 12:04 pm    Post subject: Reply with quote  Mark this post and the followings unread

g.gabba wrote:

i understood that it is acting like a RM?


Posted Image, might have been reduced in size. Click Image to view fullscreen.

cheers, gabi


Hi Gabi:
Not quite; I am saying that to my ears it can, sometimes, sound a bit like an RM.

I don't think this circuit could ever truly be an RM--you'd need at least 2 transformers for that right?

What I think is happening here is that any beat frequencies between the sine waves or whatever source material you feed in get emphasized by this simple circuit, causing things to sound "metallic" at times; maybe a bit like an RM in play when it's not.

If time permits I will post sound samples (including a few scope shots) in my blog. In the meantime, again, if anyone can turn me onto other zener/inductor based synth distortion units, I'd really like to see what real EE's (which means, not me!!) have come up with. Very Happy

Thanks.

_________________
Visit my AUDIODIWHY blog and website
Back to top
View user's profile Send private message Visit poster's website
AlanP



Joined: Mar 11, 2014
Posts: 746
Location: New Zealand
Audio files: 41

PostPosted: Mon Oct 15, 2018 12:09 am    Post subject: Reply with quote  Mark this post and the followings unread

http://www.madbeanpedals.com/projects/Retrograde/docs/Retrograde.pdf

The Tychobrahe Octavia uses a tranformer. (Schematic is on the last page.)
Back to top
View user's profile Send private message
PHOBoS



Joined: Jan 14, 2010
Posts: 5591
Location: Moon Base
Audio files: 705

PostPosted: Mon Oct 15, 2018 4:42 am    Post subject: Reply with quote  Mark this post and the followings unread

just a quick note: I am not so sure if that zenerdiode across the inputs is such a great idea, as it pretty much
shorts them when the voltage on input 2 is lower than the voltage on input 1.

_________________
"My perf, it's full of holes!"
http://phobos.000space.com/
SoundCloud BandCamp MixCloud Stickney Synthyards Captain Collider Twitch YouTube
Back to top
View user's profile Send private message Visit poster's website AIM Address Yahoo Messenger MSN Messenger
cslammy



Joined: Apr 27, 2018
Posts: 206
Location: USA
Audio files: 1

PostPosted: Mon Oct 15, 2018 9:30 am    Post subject: Reply with quote  Mark this post and the followings unread

PHOBoS wrote:
just a quick note: I am not so sure if that zenerdiode across the inputs is such a great idea, as it pretty much
shorts them when the voltage on input 2 is lower than the voltage on input 1.



Thanks Phobos, for final design I will buffer the inputs.

_________________
Visit my AUDIODIWHY blog and website
Back to top
View user's profile Send private message Visit poster's website
cslammy



Joined: Apr 27, 2018
Posts: 206
Location: USA
Audio files: 1

PostPosted: Mon Oct 15, 2018 9:31 am    Post subject: Reply with quote  Mark this post and the followings unread

AlanP wrote:
http://www.madbeanpedals.com/projects/Retrograde/docs/Retrograde.pdf

The Tychobrahe Octavia uses a tranformer. (Schematic is on the last page.)


Thanks AlanP!

_________________
Visit my AUDIODIWHY blog and website
Back to top
View user's profile Send private message Visit poster's website
gabbagabi



Joined: Nov 29, 2008
Posts: 651
Location: Berlin by n8
Audio files: 23

PostPosted: Tue Oct 16, 2018 2:33 am    Post subject: Reply with quote  Mark this post and the followings unread

dont worry about it is a RM or not Cool
it would just be nice to see how it is behaving
Back to top
View user's profile Send private message
cslammy



Joined: Apr 27, 2018
Posts: 206
Location: USA
Audio files: 1

PostPosted: Fri Oct 19, 2018 2:18 pm    Post subject: Reply with quote  Mark this post and the followings unread

OK Blog post is done. Sound demo, scope photos.

I might create a PCB if there is interest.

http://audiodiwhy.blogspot.com/2018/10/zener-synth-distortion-alive-and.html

Comments appreciated. Phobos: I only buffered one of 2 inputs, seems OK to me, what do you think?

_________________
Visit my AUDIODIWHY blog and website
Back to top
View user's profile Send private message Visit poster's website
gabbagabi



Joined: Nov 29, 2008
Posts: 651
Location: Berlin by n8
Audio files: 23

PostPosted: Sat Oct 20, 2018 4:21 am    Post subject: Reply with quote  Mark this post and the followings unread

cool! Cool

very nice soundworks indeed, 2:35 is of course my favrorite, but also the low amplitude sine part, those little extra noises, nice

cheers, gabi
Back to top
View user's profile Send private message
PHOBoS



Joined: Jan 14, 2010
Posts: 5591
Location: Moon Base
Audio files: 705

PostPosted: Sat Oct 20, 2018 9:32 am    Post subject: Reply with quote  Mark this post and the followings unread

I don't think a buffer is really necessary, but a good idea nontheless, as long as you have at least a resistor in series with one of the inputs
it should be good. For the "Son of Zener" I'd buffer the input connected to the transformer or you could buffer both for good measure.

Sounds pretty cool, not what I expected.
g.gabba wrote:
..2:35 is of course my favrorite..

yep Razz


Nice bees too Laughing ("Not the bees!")

_________________
"My perf, it's full of holes!"
http://phobos.000space.com/
SoundCloud BandCamp MixCloud Stickney Synthyards Captain Collider Twitch YouTube
Back to top
View user's profile Send private message Visit poster's website AIM Address Yahoo Messenger MSN Messenger
cslammy



Joined: Apr 27, 2018
Posts: 206
Location: USA
Audio files: 1

PostPosted: Sat Oct 20, 2018 12:27 pm    Post subject: Reply with quote  Mark this post and the followings unread

[quote="PHOBoS"] For the "Son of Zener" I'd buffer the input connected to the transformer or you could buffer both for good measure.

Resistance across the primary side of the transformer is only about 50 ohms so I agree, it's safe to buffer it. I ended up buffering both inputs.

Thanks.

_________________
Visit my AUDIODIWHY blog and website
Back to top
View user's profile Send private message Visit poster's website
Psynth



Joined: Jul 18, 2018
Posts: 34
Location: UK
Audio files: 8

PostPosted: Sun Oct 21, 2018 3:18 pm    Post subject: Reply with quote  Mark this post and the followings unread

Interesting circuit. I've played around with it in LTSpice, and it seems to behave like a cross between a ring mod and a logic gate. Basically the diodes, being zeners, can conduct in both directions, but with different threshold voltages (the zener voltage in the reverse direction, and the normal 0.7V diode forward drop in the other direction).

Putting in identical sine waves to both inputs results simply in the same frequency at the output. But putting in say 440Hz and 880Hz produces a sort of anharmonic series of diminishing amplitude, at 1320Hz, 1.76kHz, 2.2kHz etc.

It also seems, in spice at least, that the transformer is not essential for the operation of the circuit (though it may impart musical colour). The attached screenshot shows the transformer replaced with the two diodes feeding both + and - inputs of an opamp.

Not breadboarded yet though, so don't know what this would sound like in practice.

Peter


Screenshot 2018-10-21 23.16.39.png
 Description:
 Filesize:  89.39 KB
 Viewed:  398 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

Screenshot 2018-10-21 23.16.39.png


Back to top
View user's profile Send private message
Psynth



Joined: Jul 18, 2018
Posts: 34
Location: UK
Audio files: 8

PostPosted: Sun Nov 18, 2018 10:38 am    Post subject: Reply with quote  Mark this post and the followings unread

Got round to breadboarding this. Very good sounds from such a simple circuit. I've not used a transformer, and have added opamp buffers and an additional moderator input- which acts like a sort of VCA.

Schematic attached (for a dual version).

A quick sample is attached. This is just two sine waves, at 178 and 280 Hz. At about 20 secs I start to turn the 'mix' pot up, then play with the 'mod' pot and the 'offset' pot. At about 1.15 I put a triangle LFO into the 'mod' input. From 2.12 onwards, variously changing the sine wave frequencies, then from 2.50 swapping the LFO out for an audio frequency saw - from 3.30, this is controlled by a sequencer.

Peter


Zener modulator.png
 Description:
 Filesize:  22.77 KB
 Viewed:  335 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

Zener modulator.png



Zener demo.mp3
 Description:

Download
 Filename:  Zener demo.mp3
 Filesize:  3.63 MB
 Downloaded:  577 Time(s)

Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic
Page 1 of 1 [16 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software » The layout factory
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Forum with support of Syndicator RSS
Powered by phpBB © 2001, 2005 phpBB Group
Copyright © 2003 through 2009 by electro-music.com - Conditions Of Use