CMOSerizer Distortion

[WGTP]

The ROG Mr. EQ meets a CMOS distortion.  Active and passive EQ versions.  Complimentary mosfets, open loops, 4049 madness/goodness.  Hotter than August/cooler than an ice burg...

http://www.aronnelson.com/gallery/main.php/v/WGTP/CMOSerizer.gif.html?g2_imageViewsIndex=1

[Brymus]

Sweet ,I have had that bookmarked since you mentioned it in my thread awhile back.
Do you mind if I try to incorporate part of it in my CMOS distorter I am working on ?

[Mark Hammer]

I noticed that the Emma Reezafratzitz has a control to vary the current to the V+ pin on the 4049.  This is a simpler version of what Charles R. Fischer implemented on this circuit here: http://www.generalguitargadgets.com/content/view/36/27/

Replace the 470R current-limiting resistor with 330R and a 1k pot/variable-resistance and tell me if you like what you get.

[WGTP]

It's not like I invented any of this, please feel free to use what you like.  ROG and STM deserve the credit.  

[Brymus]

I noticed that the Emma Reezafratzitz has a control to vary the current to the V+ pin on the 4049.  This is a simpler version of what Charles R. Fischer implemented on this circuit here: http://www.generalguitargadgets.com/content/view/36/27/

Replace the 470R current-limiting resistor with 330R and a 1k pot/variable-resistance and tell me if you like what you get.

Darnit this is what partially controls the gain in my design,if you read my CMOS gyrator thread you'll find I mentioned that.
In my design I use a pot to change the voltage from about 2V up to around 16V ,this dramatically effects the distortion and tone of the pedal.
From smooth/vintage to over the top...It also uses two sets of clippers shunted to ground on a switch.
It will kick your tube amp harder than a RM on steriods.
I use a 25K pot in a Pi filter set up,I think it probably works much better than the set up you mentioned,but I havent tried what you suggest.
I should of known I wasnt the only one to do this 

@WGPT,thanks I have been working on this off and on since last October/November a friend asked for a 3LD for X-Mas but I wasnt happy with the tone/noise - one mod led to another,ect ,ect then after breadboarding all the CMOS pedals I could find it turned into something kinda original.
Replacing the passive tone controls with active ones using the unused stages is all thats left before I am happy with it.
I should probably draw it up and let you smart folks help me finish it 
This is also the one that is going to use the LED clippers for eyes,but now everyone and their dog has done that(wont seem original anymore),thats what I get for being slow on the draw I guess.

[Brymus]

I should note at one point I asked DShwartz to help me but decided to try and figure it out on my own.
And sorry for hi jacking your thread WGTP

[Mark Hammer]

I should note that I have not tried out the current limiting myself, and neither am I in a position to comment on whether the use of an active and stable current-limiting device like the LM334Z that Fischer used presents any audible advantages over a simple variable resistance.  Worth exploring though.  Unfortunately, you can't ask Fischer, because he's deceased.  The EM Fuzz was his last effort, and published in Electronic Musician post-humously.

[WGTP]

Since this is on the bread board, I usually switch between a 470 and 1k resistor.  I started to draw it with a 1k trim pot.  It does have a big effect on the "character" of the thing.  There are so many possibilities.  Some times I add LED's in the FBL of the last distortion stage for something a litttle different.  

Also there are many others who have contributed to the CMOS distortion designs, including Mark, Frank Clarke, etc. clear back to the Tube Sounding Fuzz dude that got me started on this stuff 35 years ago.  Craig Anderton 

[dschwartz]

I should note at one point I asked DShwartz to help me but decided to try and figure it out on my own.
And sorry for hi jacking your thread WGTP

me? what? who? when?

[Brymus]

I should note at one point I asked DShwartz to help me but decided to try and figure it out on my own.
And sorry for hi jacking your thread WGTP

me? what? who? when?

Geez IDK when, it was months ago I know that,try looking through your PMs to see if its still there.
As you never answered the last one I sent you.

[Mark Hammer]

Just noticed this circuit too: http://runoffgroove.com/ubescreamer.html
It also suggests use of a variable resistance between the V+ pin and +9v.

[WGTP]

It seems that most of the CMOS circuits I have noticed lately are using a small resistor with 9v.

I totally forgot to mention that the boost sections can be turned on/off.  Also, Mr. EQ has a mid-boost section that I didn't use.  Check out the Mr. EQ schematic for details. 

[Nasse]

I think one IC juice demand is small enough so you can fire it from voltage divider or pot

[Lurco]

Just noticed this circuit too: http://runoffgroove.com/ubescreamer.html
It also suggests use of a variable resistance between the V+ pin and +9v.

and don`t forget the electrolytic from the IC pin to ground!

[Fuzz Aldryn]

I think one IC juice demand is small enough so you can fire it from voltage divider or pot

Yep, I used a 10k lin pot in my design with pretty pleasing results. From smooth more us sounding to tight brit sounds.

Cheers
Helge

[Brymus]

Well that settles it, I am definitely not the only one to do this voltage gain control set up.
Whats interesting at least to me is how I stumbled across it.
I was having issues with oscillations form my CMOS build and after searching the forums here the only remedy I could find were several posts saying the 4049 does not like anything but fresh 9V batteries.
Most posts were requests asking for help only to be answered by the OP that a fresh 9V solved the issue.
Well that didn't work for me but I took it as maybe my IC was a little different,and decided to use an adjustable 0-12V supply to see if more voltage equalled less oscillations.
Sure enough once I got up to just under 12V the oscillation stopped or at least moved to an inaudible frequency.
But then the problem was getting 12V in the pedal w/o a wart.
Reading data sheets showed the IC could take up to 20V so I started playing with more voltage and noticed the distortion got tighter and heavier the higher I went.
When I finally found adding the small value (I used 22n) cap at the V+ pin stopped the oscillations ( I can now run it as low as I want w/o any issues) I was hooked on the tone from the 12V or higher V+ was giving me.
Then the massive bread boarding began - Frank Clark's notes were a big help...
A little tweaking and I could get an almost clean sounding distortion at around 4-5V or less to a just over the top high gain sound 12V or higher.
I really don't consider it my design (more like my happy accident/discovery) since most of the changes were tweaks that sounded good,or borrowed from other CMOS builds.
I would highly recommend anyone doing a CMOS distorter to look at all the Hot Harmonic versions,and all the ROG CMOS versions,as well as the Craig Anderton design.
I found after trying all the different ones I was able to tweak mine in a way that was most pleasing to me.
But I really did think I had found something unique in the variable voltage as a gain control... Oh Well at least I did discover it on my own.

[edvard]

Have you seen this?
http://www.geofex.com/circuits/+9_to_33.htm

[WGTP]

IIRC Tim Escobedo (someone else to acknowledge) said to use a large electro across the + and - to minimize oscillation, so I have a 470uf and don't have problems until the battery starts getting down to less than 5v or so.  I mostly use the small resistor to make the battery last longer.  It has so much gain, it doesn't need higher voltage, but maybe I'll try a couple of 9v in series or even a new 9v.