DIY SHO

[BDuguay]

I have this "friend" who is completely nutty over the Zvex Super Hard On but, because he is not blessed with a limitless monetary supply, he cannot afford one.
He does however posess the skills and wherewithall to make one for himself. The problem is he's not sure which of the many projects to choose from that will give him the results he wants. He also doesn't want to do anything unethical in the eyes of his fellow DIY'ers
Please help me help my "friend".
Brian
a.k.a. Friend

[AL]

Go to the AMZ page http://www.muzique.com/  and build the Mosfet Boost located on the projects page or order the CD and build the mini-booster.


AL

[Samuel]

Yeah two MOSFET boosts or two LPBs side-chained would at least approximate the effect (before everyone comes in her shouting that the ZVEX pedal is not based on either of those designs....I'm sure it's not, but it sure looks like its two boosters chained end to end). Maybe a MOSfet into an LPB would work good for the distortion factor.

[BDuguay]

Okay, so my "friend" is actually me. I had a SHO that belonged to a friend of mine.... no really, a different friend... and he wanted me to install a DC jack. I had heard so much about these pedals that, as soon as I was finished working on it, I was very curious to test it out. Needless to say it impressed the hell out me. Even so, I never had the urge to open it back up and reverse engineer it. I still want one though.
Brian

[AL]

Jack's boosters are very well liked.  I have a Mosfet Boost on board now - it needs a few tweeks and will be ready to go.  Do a search and I think you'll find plenty of good reviews on the AMZ boosts.  You'll also have the shcem so you can fiddle with it until you get it where you want it - at a fraction of the cost.

AL

[Mark Hammer]

I've heard you play, Brian, and I've seen your rig.  Build the MosFet booster.  You'll be plenty happy with it.  Ten million ohms of input impedance can't be wrong!  (Just like 50 million Elvis fans)

For gigging purposes, note that since gain is set by a resistance to ground, it is a nobrainer to stick one in a 1590BB, with a master bypass stompswitch, a gain-amount-1 pot, gain-amount-2 pot, and a DPDT to switch which pot to ground plus an indicator LED.  Alternatively, since I can see few reasons why you'd ever want to take it *out* of circuit, drop the master bypass switch and have a basic-level pot and boost-level pot.

[petemoore]

Whew   :roll:

[BDuguay]

Say Mark, my curiosity is now officially piqued(sp?)
I think I know where you going with this... please splain more if you would.
Brian

[puretube]

no wonder ladies don`t show up in this forum
with thread titles like this one...

(LOL)

:lol:  :wink:

[Mark Hammer]

Okay, Lucy.  Looks like *I'm* the one with ess-plaining to do.

If you get the document from Jack's site (http://www.muzique.com/schem/mosfet.htm), you'll see that gain is set by the 5k pot (R6) to ground, just one variable resistance.  So, howzabout you have two pots (two, two, two pots in one!) where R6 is.  

The stompswitch would have to switch things in parallel (switching between them would have a pop, more audible with a bigger cap, and 100uf is more than big enough).  

If I understand these things, though, decreasing the resistance of R6 raises gain, so what you could do is simply stick a larger value (e.g., 47k) fixed resistor in there from the cap to ground to assure the 100uf cap drains off, and use the stompswitch to tie one pot or another to ground.  The pots are in parallel with that added fixed resistor, whether it is 47k or whatever.

Ultimately, no different than having an op-amp where you switch gain-setting resistors.  Somebody will, I hope, have something more intelligent to say about what reasonable resistance values would be.