Another Dual Soft clip Distortion

[WGTP]

http://aronnelson.com/gallery/WGTP/Infinion?full=1

Latest dual soft clip distortion on the breadboard.  Uses Joe Davidson's soft clip diodes and John Green's Mosfets.  Hope someone will try it for some feedback.  It's pretty smooth.   

[MartyMart]

Looks interesting , wish I has time right now ... but .....

Cheers,

MM.

[Arn C.]

Howdy!
    Circuit looks great!
  What IC did you use and also what mosfets did you use?

Thanks!
Arn C.

[dano12]

http://aronnelson.com/gallery/WGTP/Infinion?full=1

Latest dual soft clip distortion on the breadboard.  Uses Joe Davidson's soft clip diodes and John Green's Mosfets.  Hope someone will try it for some feedback.  It's pretty smooth.   

Arghh! I just got my rat design finalized and you have to come along with more interesting stuff I think I'll need a bit of time to wrap my head around the schematic, especially what is happening around the 1N4818s.

[WGTP]

http://www.diystompboxes.com/analogalchemy/misc/softclip.html

Here is the soft clip diode info, and below is the Mosfet info. 

http://www.elixant.com/~stompbox/smfforum/index.php?topic=38581.0

Supertex has some Mosfets that have the desired characteristics, I'm sure other brands do to. 

Last night I changed the resistors in the feedback loops to 1M.  That made it "Bark" with more authority.  The Mosfets are different than the normal diodes in that you can use rediculas levels of gain and it still stays smooth.  Having them after the diode distortion seems to add a compression effect.

The op amp is a 2262 from TI with the battery running around 7-8v.   

[Arn C.]

Thanks WGTP!!!!!!!

   So, the Mosfet used could be 2n7000?   I have some of those(fingers crossed)


Arn C.

[brett]

Hi
Wow.  This looks very interesting.

Just a suggestion: for the final high cut, make the resistance and cap values larger, because otherwise the cut will depend on the chip used.  Chips vay in output impedance by about as much as the 1k resistor that you are using.  Alternatively, you could nominate a particular chip that must be used, or suggest one with middle-of-the-range output impedance.  TL072s are really popular, and have a nice, consistent, low Zout of about 150 ohms.

cheers

[markm]

I like it.
Worth checking out for sure. 

[searoad]

looks really killer!!

can you kindly record some clips with 3-mode switched?

[WGTP]

If I could stop working on distortions, I could/would learn how to to make clips.   

Interesting point about the treble cut.  A 10K could be used there by adjusting the values of the low and high roll off.  I hadn't thought about the output impedence varying that much.  My SS PV amp is pretty dark, so I don't use much treble cut, but other amps might need it.

2N7000/BS170/BS250 will work and appear to have a lower threshold than the IRC520 that has been referenced.  The issue is getting a low enough clipping threshold that the op amp doesn't start breaking up.  That is why I use rail to rail, although I can't say I have tried the standard ones that much with Mosfets.

Most of the part values can be tweaked for different amp/guitar/speaker/room/etc. preferences.  Definitely experiment with the Bass Boost values.  It really helps with small open back cabinet amps, just don't push them to hard.  The bass boost is really a treble/midrange cut and reduces the output.  For SS amps that isn't a problem.

Last night I went back to 100K in the second feedback loop and found that preferable.  Dropped the gain for that stage from 1000 to 100.  With 1M in there, it was a little un-natural sounding, too much compression and rolled off to many highs.  As John Green has said, the Mosfets are "Darker" than typical diodes.