Zvex Super Hard On

[frequencycentral]

"Newer SHO units have a diode protection circuit to keep the transistor from blowing"

So is that the 1n4148's in my layout?

........and why does the Sho have three 1/4 inch sockets?

[sevenisthenumber]

"Newer SHO units have a diode protection circuit to keep the transistor from blowing"

So is that the 1n4148's in my layout?

........and why does the Sho have three 1/4 inch sockets?

bump

[moose23]

"Newer SHO units have a diode protection circuit to keep the transistor from blowing"

So is that the 1n4148's in my layout?

........and why does the Sho have three 1/4 inch sockets?

There's a single 12V or 9.1V Zener protection diode in some of them. From the centre leg(control G) to ground. 12V in the SHO and two 9.1V in the Super dooper. The third 1/4 inch socket is a second output.

[krhnyc]

when you say center leg (control G), what do this mean? It seems like a simple fix, just need to know where to put it.

[frequencycentral]

To answer my own question.

The versions with the two diodes are the older version and it's easy to blow the mosfet by plugging in an input cable while its powered on.

ZVex modified the later ones with a 9.1v zener diode between source and gate, and removed the other two diodes. Zener cathode connected to the gate.

[BoxOfSnoo]

The versions with the two diodes are the older version and it's easy to blow the mosfet by plugging in an input cable while its powered on.

ZVex modified the later ones with a 9.1v zener diode between source and gate, and removed the other two diodes. Zener cathode connected to the gate.

Do you have a schematic for this so it will be a bit more clear?  I don't quite understand what changes to make...

[slacker]

Do you have a schematic for this so it will be a bit more clear? 

It's the same as how the zener diode is connected on this http://www.muzique.com/schem/mosfet.htm

[BoxOfSnoo]

And it's safe to get rid of the other two diodes entirely?  It's confusing me I guess 'cause it's location is fairly different.  I suppose electrically it's almost the same thing?

Edit: Looks like it!  I found a layout on the other site, looks very simple.  I gotta try this now.

[frequencycentral]

I notice some people use a lin pot instead of a rev log - any comments on that?

I also notice different pot values are used - does the value matter, as long as it's the same value as the drain resistor?

The version II seems preferable, ie a zener instead of the two 1n4148 - I also notice some people just use a LED instead of a zener - any LED? Comments on LED vs zener?

Thanks!

[soggybag]

I built one with a linear pot and all of the gain is bunch up at the end of the pot travel. Definitely use a reverse log pot.

The gain is roughly Rd divided by Rs.

I put an LED across the gate and source of the MosFET because the RunOffGroove guys did it. Hey if they jumped off a bridge I'd follow them, and often it would sound great. I was just copying the Peppermill: http://runoffgroove.com/peppermill.html There are some notes on this here.

[krhnyc]

I just built a SHO for a friend, using my super compact layout below. Nice boost, but it does indeed crackle like grandpa's 78's. Might seem like a daft question, but why not just ground the source, remove to resistor to ground at the output, and use a pot configured as a voltage divider at the output for a volume control? Or am I missing something?

Question, in  the pic showing parts layout, are they shown on the solder side or the component side? Hate to sound like a noob, but the pic is a little confusing.

[tiges_ tendres]

I just built a SHO for a friend, using my super compact layout below. Nice boost, but it does indeed crackle like grandpa's 78's. Might seem like a daft question, but why not just ground the source, remove to resistor to ground at the output, and use a pot configured as a voltage divider at the output for a volume control? Or am I missing something?

Question, in  the pic showing parts layout, are they shown on the solder side or the component side? Hate to sound like a noob, but the pic is a little confusing.

No the picture is fine.  The overlay when put on a pcb is correct.  When you flip it over, it matches the layout.  You put your parts in on the non copper side corresponding with how the graphic looks.

It's confusing, but that particular layout software allows you to do everything from the top side of the board.  Which is way less confusing than having to rotate everything in your head.

[therecordingart]

I can't get this layout to print at the right size for the life of me. What are the dimensions supposed to be? Do I have to scale it down?

[TimWaldvogel]

i gotta ask this cause i had a thread about this pedal awhile back and never really felt i got a straight answer.
i dont have the proper diodes. i only have 1N400x's and a a few 12v zener diodes. any way i can build this thing without frying it?

[slacker]

1N400Xs will do the job.

[frequencycentral]

i gotta ask this cause i had a thread about this pedal awhile back and never really felt i got a straight answer.
i dont have the proper diodes. i only have 1N400x's and a a few 12v zener diodes. any way i can build this thing without frying it?

......or use your 12v zener thus:

"Newer SHO units have a diode protection circuit to keep the transistor from blowing"

So is that the 1n4148's in my layout?

There's a single 12V or 9.1V Zener protection diode in some of them. From the centre leg(control G) to ground. 12V in the SHO and two 9.1V in the Super dooper.

[therecordingart]

Do I need to do anything special to get the your layout to print the correct size?

[quarara]

Do I need to do anything special to get the your layout to print the correct size?

http://www.diystompboxes.com/smfforum/index.php?topic=80316.0

[therecordingart]

Do I need to do anything special to get the your layout to print the correct size?

http://www.diystompboxes.com/smfforum/index.php?topic=80316.0

No access to Photoshop. I'll shoot someone a few bucks if you can get this to the correct size and put it in pdf form for me...or any way that it'll print correctly. I've been printing different sizes and trying to fit parts but can't get it right.

[quarara]

Do I need to do anything special to get the your layout to print the correct size?

http://www.diystompboxes.com/smfforum/index.php?topic=80316.0

No access to Photoshop. I'll shoot someone a few bucks if you can get this to the correct size and put it in pdf form for me...or any way that it'll print correctly. I've been printing different sizes and trying to fit parts but can't get it right.

If you don't have PS you can always download GIMP instead. It's freeware and really similar to PS. I would do you the scaling for free, but I'm not at home at this moment.