i want to build a modified sho

[stopstopsmile]

or a variation on the booster
i like the sound of the sho but
its a bit bright and can be harsh
i also don't like the voltage crackle
but i like how simple the design
how can i tweak out that circuit
to make it still have the sparkle and
boost and tightness but get rid of the harsh?
and get rid of the voltage bias crackle?

I have played with some of the other boosts out there
and the sho gets closest for me but not quite.
i like the boost in the box of rocks more but i know
thats a modded sho, so any hints or pointers
or a schematic to get me started on this?

[zyxwyvu]

You can try the AMZ Mosfet Booster. It is very similar to the SHO, and does not crackle like the SHO. If it is too bright, you can try decreasing R3 to decrease the input impedance.

[stopstopsmile]

i have played with the orman booster, it doesnt get the sparkle like the sho.  It seemed a tad bland.  How can I modify it slightly to give me more sparkle and have a nice tight clear tone with nice bass? 

[blanik]

my SHO isn't too bright if i don't put it first in the chain, i put it after a buffered tuner and it minimizes the brightness a little, but then it also kind of defeat the purpose of it...lol

[stopstopsmile]

also ormans layout that i used seemed a bit large
i like the very compact idea of the sho as you can build
it up and throw it in a guitar. 

[jonathan perez]

do you plan on throwing it in a guitar?

[stopstopsmile]

yes i do

[markm]

It is next to impossible to eliminate the crackle from that circuit so therefore, it MUST be "Okay".
One thing you can do is set the Gain with a Trimmer and hook up a Master Volume to the output ala the "ViagraTone" in my Gallery. 

Have a look;
http://www.aronnelson.com/gallery/v/MarkMs-Gallery/album15/album76/ViagraTone_II_LAYOUT.jpg.html

[JHS]

I would use the old SHO-circuit as a base, the new circuit sounds a bit harsher and thinner but therefore it's more neutral.
You can subs the 10M for 4,7/3,3 or 2,2M, for a more BOR-boost sound, with 1M it will sound like the Landgraff D-boost.

Further finetuning of the tone can be done by altering the I/O caps and a 47n across the power supply will give stronger highs if needed.
Different types of C (MKP, MKT, MKS, MKH and multilayer ceramic) produce slightly different tone nuances.

The crackle knob is something to live with and the reason for the typical SHO-sound.

Step through 4 -5 BS170, to fetch a good one, they stray a lot and some can sound really harsh, others are more mellow sounding and National S. sound a bit different than Fairchild BS170.

JHS

[markm]

The crackle knob is something to live with and the reason for the typical SHO-sound.

Step through 4 -5 BS170, to fetch a good one, they stray a lot and some can sound really harsh, others are more mellow sounding and National S. sound a bit different than Fairchild BS170.

JHS

Two VERY good points!
I agree! 

[the_random_hero]

I replaced the BS170 with a J201. It sounds rather nice to my ears, I think I even like it more than stock.

[stopstopsmile]

can someone send me a really tight layout for the sho?

[markm]

can someone send me a really tight layout for the sho?

I kinda thought the layout I posted was small? 

[stopstopsmile]

mark, i am sorry i clicked on what you put up there but i didn't know exactly what was for, I thought you were saying it was just for a gain control.  Sorry.

I am new to this. 

I had a quick thought, how could I modify the orman mosfet into a cleaner kind of landgraff boost type and does anyone have a super small layout.

The reason I ask is, i want to fit it in a guitar.  And I just remember that the sho I had went through mosfets like mad.  Always burning up.  Whereas the orman from what I read doesnt crackle and doesn't burn up mosfets.

thanks guys

[markm]

Have a look;

http://www.aronnelson.com/gallery/v/MarkMs-Gallery/album15/album76/MosfetBooster_LAYOUT.gif.html

This here may actually be a better choice for what you are trying to accomplish;

http://www.aronnelson.com/gallery/v/MarkMs-Gallery/album15/album76/Gus_Boost_LAYOUT.gif.html

[ubersam]

I replaced the BS170 with a J201. It sounds rather nice to my ears, I think I even like it more than stock.

Isn't BS170 a MOSFET and the J201 a JFET? Did the J201 just drop in to the circuit without any changes to the biasing?

[Dave_B]

And I just remember that the sho I had went through mosfets like mad.  Always burning up. 

Do you recall if the SHO had the zener across the BS170?  I'm guessing it didn't from your circumstances.

Anyone notice how hard it is to get SOT-23 BS170's in small quantities?

[JHS]

You can replace the BS170 with nearly any NPN BJT w/o rebiasing, but I would drop the Zener or other diode protection. A FET will work too, but maybe be the 5,1k must be altered to set the correct BIAS for the FET.

Nearly every modern Mosfet has a internal protection diode, so you can drop the zener in most cases, but the zener has an audible influence on the sound.

A simple FET-Boost with a following BJT-boosterstage is also fine, the FET generates the "sound" and the BJT-Stage adds the volume swing.

JHS