crackle NOT okay

[nightingale]

Man those BS170's are sensitive!
My SHO clone went down on stage on the night of the 10th. I left it plugged in after sound check [forgot the -9v was hooked up to the output jack]. I plugged the input back in and there and no more SHO?

I had a sketchy feeling about the SHO blowing the mosfets, so I had a friend bring one of his lpb2 clones to the show just in case. good thing!

ry

[the_random_hero]

Did you use the Zener to protect the BS170? That's apparently meant to stop frying the mosfets, I haven't fried mine yet so I can't comment

[Paul Marossy]

Just for the record, my "SHO" work-alike only has a little bit of crackle when I turn the knob. It uses a BS170. 

[blanik]

Did you use the Zener to protect the BS170? That's apparently meant to stop frying the mosfets, I haven't fried mine yet so I can't comment

there was two SHO designs (for what info i could get from Z's website and forum) the early one was unprotected and would blow their BS170 just by looking at them the wrong way... and they had an extra 170 taped inside the enclosure for that purpose... and how to differenciate the old from the new? the old one had the output jack switching the power, on the new design it's the input jack that's switching the power on... like all the other pedals...

then they changed the design a little bit to give more protection to the 170 but i don't see any zenners in all the schems floating around on the net...?

R. 

[the_random_hero]

Did you use the Zener to protect the BS170? That's apparently meant to stop frying the mosfets, I haven't fried mine yet so I can't comment

there was two SHO designs (for what info i could get from Z's website and forum) the early one was unprotected and would blow their BS170 just by looking at them the wrong way... and they had an extra 170 taped inside the enclosure for that purpose... and how to differenciate the old from the new? the old one had the output jack switching the power, on the new design it's the input jack that's switching the power on... like all the other pedals...

then they changed the design a little bit to give more protection to the 170 but i don't see any zenners in all the schems floating around on the net...?

R. 

In one of the schematics I built my pedal off (which Zvex has said was wrong, but it sounds pretty damn good to me), there is a 9.1 Zener between the signal-side of the 10M resistor and the source of the BS170 - I think this is the newer version. The other schematic is missing the Zener, but the output jack is switching the power.

[freddd]

I've built the one with the 1N4148/914's in it. Which one is it supposed to be!?

[nightingale]

No,
My SHO work-alike does not have the protection zener. I plan to pick up a genuine zvex SHO sooner than later. [mostly because I like the aesthetics]. For now I might look into trying Jacks mosfet boost, or add the zener from Jacks mosfet boost. I will just keep this one around for a backup.

I really dig the sound of these mosfet type boosters. I keep mine on "full time". Just like it says on the zvex site: it really seems to bring the best out of my American vintage 62 strat pickups!

take it easiest,
ry

[blanik]

No,
My SHO work-alike does not have the protection zener. I plan to pick up a genuine zvex SHO sooner than later. [mostly because I like the aesthetics]. For now I might look into trying Jacks mosfet boost, or add the zener from Jacks mosfet boost. I will just keep this one around for a backup.

I really dig the sound of these mosfet type boosters. I keep mine on "full time". Just like it says on the zvex site: it really seems to bring the best out of my American vintage 62 strat pickups!

take it easiest,
ry

i'm always thorn between using it before the other pedals or at the end.. and what about my old unbuffered wah, should i put the SHO after (i'll lose the high impedence input of the SHO when using the wah)

how does it sound when you drive other pedals hard with a SHO, they must distort like crazy...??

[jlullo]

why is it that the protection diode is a zener and not just a regular diode?

[spudulike]

The zener clamps the gate voltage to no more than the zener rating (eg 9V1). Google for zener principles (sometimes called avalanche diodes which is a pretty good description).

[bean]

I built one a while back in a tiny box. Originally, it had a trim inside for use as a master volume, but I ended up taking it out. Still, I like the plain vanilla Mosfet Booster as well or maybe even better. To me, they are quite different sounding.

[petemoore]

  I bet I'd love the SHO sound, most seem to.
  Sfars boosters, I have them all before/after and during...
  One up front for general boost soundings and driving Fuzzes, now Omega.
  Two compressors in the middle [both boost-a plenty also], I like them comps too, and they seem to help out Octaves and Phasers, and Fuzzes etc. in a compy way. The OS is close to stock, NE553x opamp, the Dyna is 'breathed on', and can dip the signal a good bit.
  The last pedal is an IRF510 booster type, what I ended up with after reading mosfet boosters update at GEO while studying a schematic Gus drew, building a couple and diddling with S/D values, 4m7 input resistor.

[nightingale]

No,
My SHO work-alike does not have the protection zener. I plan to pick up a genuine zvex SHO sooner than later. [mostly because I like the aesthetics]. For now I might look into trying Jacks mosfet boost, or add the zener from Jacks mosfet boost. I will just keep this one around for a backup.

I really dig the sound of these mosfet type boosters. I keep mine on "full time". Just like it says on the zvex site: it really seems to bring the best out of my American vintage 62 strat pickups!

take it easiest,
ry

i'm always thorn between using it before the other pedals or at the end.. and what about my old unbuffered wah, should i put the SHO after (i'll lose the high impedence input of the SHO when using the wah)

how does it sound when you drive other pedals hard with a SHO, they must distort like crazy...??

I use my mosfet boost at the end of my pedal line[before my amp].
I only use 2 pedals live. [russsian bmp clone->mosfet type boost] Most of the time I go for a sparkley clean sound with a ton of fender reverb. Through the true bypass switching on the muff clone, the SHO type booster is connected directly to my PU's. Every now and then when I switch on the muff clone for a psyched out lead, I am not worried about the loading of the pickups. So the last position works better for me. If i was to stick a wah in there, I would put it after the booster.  I keep my tuner out of the line until I tune. [usually one time per set]. I don't like the way my fuzzztone sounds with the tuner inline?

hope this helps,
ry

[spudulike]

So its ok to discuss ZVex schematics now ?

[MartyMart]

So its ok to discuss ZVex schematics now ?

Hugh , seems like it's OK with the "SHO" but I'm not sure about anything else !!!

[Auke Haarsma]

well, I'm not sure about that MM.

There used to be a thread (posted Feb 1 2007) where Mr Vex commented on debugging a SHO, he gave some vague tips on where to debug. I think that triggered some to believe SHO is ok to discuss now. However... that thread is locked/gone/off limits... url of that thread:

http://www.diystompboxes.com/smfforum/index.php?topic=53931.0

Anywayz, the SHO is becoming a common DIY pedal imho.

[Paul Marossy]

So its ok to discuss ZVex schematics now ?

Discussing is one thing. Posting schematics is another. 

[smnm]

So its ok to discuss ZVex schematics now ?

Surely the SHO is ok to discuss because it's whole evolution is documented in a series of messages between Z, Jack and others, on an earlier version of this forum archived in text-only at musique.com - I was looking at it the other day, but can't find it now...

[markm]

So its ok to discuss ZVex schematics now ?

Surely the SHO is ok to discuss because it's whole evolution is documented in a series of messages between Z, Jack and others, on an earlier version of this forum archived in text-only at musique.com - I was looking at it the other day, but can't find it now...

Afterall, legend has it that the SHO is the preamp of a vintage mixing console......if one has the schem for said console, don't you then have the SHO?

[blanik]

just finished mine! wow sounds cool! 

made it on a very small vero (5X13) i should have made the vero 6 rows and solder the pot directly on it...

i noticed a very slight hum when i turn down the volume on my guitar and this hum disseapear as soon as the guitar volume his maxed again... anyone noticed that?