zvex Sho distortion

[TimWaldvogel]

The zvex SHO has slot of output it seems, has anybody put diodes to ground after it with a volume control?

[soggybag]

There's a good idea. What about a MosFET BMP. Jack Orman made a JFet BMP.

[TimWaldvogel]

I am think a sho with asymmetrical sil 1n4001s as diodes and then a three knob tone stack followed by another SHO or tranisitor boost

[TimWaldvogel]

this is my idea, to my knowledge this is what i have translated the zvex SHO schematic to be onto perf.
the idea will be that the general sho will be providing the level boost to the clipping diodes just like an opamp would and after the output i added asymmetrical diodes to ground. i used silicon diodes so they would not distort as much cause the SHO prvides so grit as it is. and i was thinking about a marshall tonestack or fender. who knows.... anyways that would be passsive and suck volume so after the tone controls i would add something like another sho, mosfetboost, lpb-1 boost type circuit for the volume control with the 10uf dc blockage cap of course. anybody seem to hav any food for thought on this design?

[MarcoMike]

I wouldn't use a SHO for recovery, not in the usual configuration at leas... because you might want to lower the volume after the clipping stage... I'd go for something with a volume pot on the output... maybe without any other buffer stage... just like a D+, with mosfet in place of the opamp....

correct me if i'm wrong... but the signal out of the diodes could be as high as 2x diode forward voltage, so higher than 1V... that's kind of enough for tone stack, volume and everything...

[TimWaldvogel]

Well I am not entirely sure, I was contimplating a build before that replaced the first stage of a rog tonemender with a dist + circuit and after the tone stack they had a gain recovery stage. and whn you are dealing with the distortion plus it too is a large volume boost into the diodes and limited by a volume pot. But I just assumed after the advice they gave me, I may need a gain recovery stage after the 3 pot tone stack
 

[bipedal]

This idea isn't too far removed from the El-Pistolero project in the Layouts Gallery -- some component variations, different clipping diodes, but a basic mosfet boost as the core.

You might try socketing your clipping section so you can audition various diodes.  LEDs might make for an interesting clipping flavor here.

Please report back.

Jay

[MikeH]

Here's something MarkM did:  A mosfet boost with mosfet clipping.  Can't you just smell the mosfetty goodness?

http://www.aronnelson.com/gallery/main.php/v/MarkMs-Gallery/album15/album76/EL_Pistolero_LAYOUT.png.html

[soggybag]

El-Pistoleros is looking pretty cool. I love the MosFET with MosFET clipping. There's sort of a single mindedness going on here that makes me want to build this give it an enigmatic name and write glowing reviews all over the internet. Touting it's soft amp like clipping open spacious clarity of sound and the ultra high input impedance that will make you really hear your instrument for the first time.

interested buyers please PM me I'm taking pre-orders starting today.

[WGTP]

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

[gefi]

hello

I put a couple of 1N4148 and a tone control (the tone control Bigg Muff Pil BMP), works very well

[tiges_ tendres]

I think the picture is missing an output capacitor, no?

Also wouldnt you want your clipping diodes after the output cap?  Any time I put my diodes before the output cap, parts start to get hot!

[TimWaldvogel]

What are the characteristics of MOSFET clipping diodes lol? I really fell in love with any 1n400x's after I experiemented with different diodes in my dist +.
And I was wondering something, the the diodes in the zvex SHO stock circuit give it the overdrive it's known for? Maybe I should remove them in place of the diodes to ground? Or is it a voltage thing?

And thtbis correct yes, it was late last night, lol both gain stages would have electrolytic output caps. But is this a intreguing design? Unlike tHe clarity of the SHO alot

[oliphaunt]

The diode(s) in a standard SHO are static protection for the FET.

[TimWaldvogel]

Ooooooooooo ok sweet, I gotta breadboard this asap

[TimWaldvogel]

Well since I changed the voltage diodes in rthe beginning of the circuit will that hurt anything using 1n400x's instead of the stock ones??

[cpm]

Well since I changed the voltage diodes in rthe beginning of the circuit will that hurt anything using 1n400x's instead of the stock ones??

you know... they're there for protection

even bettter if you remove them and put the 9v zenner on the mosfet

[TimWaldvogel]

I am not so sure I know what you mean, aren't all diodes able to protect frOm voltages? I am just wondering why the silicon diodes would not be a smart thing

[soggybag]

I think newer versions of this uses a 9v zener from source to gate. There are some notes at Runoffgroove about using a red LED in place of a zener.

[cpm]

I am not so sure I know what you mean, aren't all diodes able to protect frOm voltages? I am just wondering why the silicon diodes would not be a smart thing

the diode pair to rails is a good protection for input not going farther than rails voltage,
but the 9v zenner does a better protection against electrostatic, IMO.

I think newer versions of this uses a 9v zener from source to gate. There are some notes at Runoffgroove about using a red LED in place of a zener.

i still cant see how a reversed LED will protect the gate, if it ever breaks down at 30v (or whatever it is common for leds) that can be enough to fry the mosfet already.