SHO not loud?

[Milotic]

Hi

I just finished a SHO clone using the schematics from DIYstomboxes.
http://www.diystompboxes.com/smfforum/index.php?topic=82566.0


I got it wired up and plugged it into the amp.  All is good, but there is a huge volume drop when turned on, even with the crackle knob to the max.
I checked the tracks for any shorts, but cant find any shorts.
I used all the parts listed there, except for the Rev. Audio pot.  Instead i used a 5k Linear pot.

Voltages:

Q1, BS170
D=4.5
G=0.40
S=0

D1 1N914
A=0.40
K=9.35

D2 1N914
A=0
K=0.40

Not 100% sure if the diodes died because of soldering, since i got lazy and didn't use a socket.

Kind Regards.

[Jhouse]

Someone correct me if I'm wrong, but the voltages don't look screwed up. Try replacing the pot with a reverse audio and check your wiring to see if any signal is being shorted to ground or is incorrectly wired.

[Milotic]

Would a 10K Lin with a 10K resistor wired the 1st and 3rd lug be suffice?

[Jhouse]

I think that will work. Try it out and see what happens.

[jacobyjd]

Are all your connections wired correctly? Unless the pot is bad, it's unlikely that changing taper will make it louder. This thing should be stupidly loud at max volume. Bad switch connection, perhaps?

[Milotic]

I 'can't' see anything wrong, but sure its probably a very small lead splatter.  I'll probably have to check with a multimeter tomorrow..

[petemoore]

  Not that those voltage readings don't look ballpark, but don't mosfets have a turn on voltage that varies among units.
  Since the V's don't look necessarily odd, try the audio probe.
  See if signal's even getting to the gate, and how loud is the drain in comparison.

[WGTP]

Remember Mosfets are easy to fry, especially in the winter months, because of static electricity.  That is why there are protective diodes.  Have you tried a different BS170? 

[Milotic]

Hey guys, i just swapped the BS170 and it started to work properly.

Thanks Petermoore and WGTP

[juansolo]

Check out the later revision SHO with the 9.1V Zener diode, supposedly it offers more protection than the 2 signal diodes.
I've got a old revision build and its easy to blow the mosfet, seems like it happens when the effect is on while the input cable is inserted or removed.

[ayayay!]

Yeah, maybe try a buffered compressor like a CS-3, then the volume pedal, then the rest of your pedals. 

[WGTP]

Cold beer, Bikinis, Hot sounds and Mosfets.  Summer projects.  Some folks use an LED instead of the zener diode.