Author Topic: crackle NOT okay  (Read 17905 times)

Stratomaster

crackle NOT okay
« on: May 10, 2007, 02:00:23 PM »
Howdy,
    So I built a clone of a pedal that will probably get me flamed.  The problem is bad enough that I'll take my chances.  I call it my Fo'(faux) Sho'.  Anyway, there are a few settings on the dial that are just filled with static.  It's not just while I turn the knob; it's at stationary positions as well.  This is very annoying.  It only happens at the higher levels in the rotation.  I like it overall, but this problem makes it very hard to want to keep it on the board.  Any suggestions?  If not, I'll probably just build me a mosfet boost or something.  I like having something to pummel the amp at the end of my chain.  Thanks in advance for any help.

Mark Hammer

Re: crackle NOT okay
« Reply #1 on: May 10, 2007, 02:26:01 PM »
I have no idea about the particulars of what you have built or if this is the source of the problem described, but if it uses a pot as a variable resistor, rather than voltage divider, make sure you are using all 3 lugs by linking/shunting the wiper with the appropriate outside lug.  This is a known best practice for reducing the risk of jittery pots and less than perfect wipers.

EDIT: And just so you know, the flaming will not result from cloning something for your personal use (that originally came from an old Neve console from what I understand).  Frowns begin when the information is posted publically and as much as declares that THIS is the necessary and sufficient information to perfectly reproduce commercial product X.  Litigation begins when home-builds magically appear on e-bay or in stores trying to pass themselves off as the original or identical to the original.  You haven't done either so relax.  No one would come down on you if you made your own Mickey Mouse plush toy or Rolls Royce for personal either.
« Last Edit: May 10, 2007, 02:31:10 PM by Mark Hammer »

Stratomaster

Re: crackle NOT okay
« Reply #2 on: May 10, 2007, 02:28:44 PM »
Did that... still noisy.  Maybe this is a sign I shouldn't be messing with this. lol

blanik

Re: crackle NOT okay
« Reply #3 on: May 10, 2007, 02:29:16 PM »
i know BS 170 are very fragile to static (the old sho had the switching jack on the output and it was stated everywhere on Z's site to bypass the effect (off) before removing the jack from the output... (hell, on the older SHO's zach even put an extra transistor in the enclosure for that reason...)

this has later been changed to a regular input switching jack with some mods to the circuit to make it more BS170 friendly...

it depends on wich layout your using and how you wired it...

Gus

Re: crackle NOT okay
« Reply #4 on: May 10, 2007, 02:37:02 PM »
The real shos I have played with crackled very little and only when the knob was turned

So something is wrong with your build not the circuit Have you tried a REAL SHO?.

could be oscillations bad battery(yes some cheap batterys have bad inside connections that can cause problems)

flux around the gate

  A good pot is needed because any DC on a wiper will cause crackle.  I would try another pot first.

less words with information
« Last Edit: May 10, 2007, 02:40:33 PM by Gus »

blanik

Re: crackle NOT okay
« Reply #5 on: May 10, 2007, 02:47:08 PM »
and also note that the pots usually found in vex's stuff are the mini square (soldered directly on the board)  enclosed pots (meaning that dirt or flux or anything can't get in...)

blanik

Re: crackle NOT okay
« Reply #6 on: May 10, 2007, 02:49:03 PM »
double post...
« Last Edit: May 10, 2007, 02:51:47 PM by blanik »

Stratomaster

Re: crackle NOT okay
« Reply #7 on: May 10, 2007, 03:44:38 PM »
Wow! Thanks for all the awesome info.  I've tried a new pot (2K) and it worked perfectly.  There's boost right from the get-go (which I like, the 5k in the schematic doesn't do much for the first 1/2 turn).  I guess I just had a bad pot.  Thanks for not flaming me!  For those of you that have both pedals, how would you compare it to the mosfest boost?  I have a MicroAmp that I like, but I prefer my clone.  Just checking out opinions.
« Last Edit: May 10, 2007, 03:48:18 PM by Stratomaster »

spudulike

Re: crackle NOT okay
« Reply #8 on: May 10, 2007, 03:51:34 PM »
If you got the schematic from a certain japanese website, then the 1M resistors around the mosfet should actually be 10M.

markm

Re: crackle NOT okay
« Reply #9 on: May 10, 2007, 03:56:29 PM »
The SHO circuit is a Favorite of mine!  8)

ambulancevoice

Re: crackle NOT okay
« Reply #10 on: May 11, 2007, 06:13:57 AM »
vintage booster!
Open Your Mouth, Heres Your Money

markm

Re: crackle NOT okay
« Reply #11 on: May 11, 2007, 06:53:32 AM »

Meanderthal

Re: crackle NOT okay
« Reply #12 on: May 11, 2007, 09:41:36 AM »
 LOL! A MOSFET as a tophat! Gotta love it! ;D
I am not responsible for your imagination.

blanik

Re: crackle NOT okay
« Reply #13 on: May 11, 2007, 12:38:14 PM »
vintage booster? is that your SHO or a different circuit? looking at the knobs it looks like a SHO with a master volume on the output...  :D

markm

Re: crackle NOT okay
« Reply #14 on: May 11, 2007, 12:43:41 PM »
vintage booster? is that your SHO or a different circuit? looking at the knobs it looks like a SHO with a master volume on the output...  :D

Yes sir.
SHO with a Master.
Like I said, a real Favorite circuit.  :icon_cool:

ulysses

Re: crackle NOT okay
« Reply #15 on: May 11, 2007, 08:59:32 PM »
There's boost right from the get-go (which I like, the 5k in the schematic doesn't do much for the first 1/2 turn).

you were prob using an audio taper pot. you need to use a reverese audio taper pot - or at least a linear pot - otherwise the first half of the turn will do very little.

cheers
ulysses

blanik

Re: crackle NOT okay
« Reply #16 on: May 11, 2007, 09:20:14 PM »
vintage booster? is that your SHO or a different circuit? looking at the knobs it looks like a SHO with a master volume on the output...  :D

Yes sir.
SHO with a Master.
Like I said, a real Favorite circuit.  :icon_cool:

for the master volume, did you use a 100k pot instead of the 100k resistor at the output? (like the second stage of the super-duper? and if so, are you able to get some kind of clipping going?)

R.

the_random_hero

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Re: crackle NOT okay
« Reply #17 on: May 12, 2007, 08:20:38 AM »
I *cough* built *cough* a SHO (I'm calling it the Stiffy :) ) and it's pretty crackle free. I used the 2N7000 FET instead of the BS170. As I only have a crap amp to test it on, I can't say how good it would sound compared to the original, but it does sound rather nice. Really brings the cleans out in the neck position.
Completed Projects - Modded DS1, The Stiffy, Toaster Ruby, Octobooster Mk. II, Pedal Power Supply

markm

Re: crackle NOT okay
« Reply #18 on: May 12, 2007, 08:55:52 AM »
I *cough* built *cough* a SHO (I'm calling it the Stiffy :) )

 :icon_lol:

markm

Re: crackle NOT okay
« Reply #19 on: May 12, 2007, 12:50:36 PM »
vintage booster? is that your SHO or a different circuit? looking at the knobs it looks like a SHO with a master volume on the output...  :D

Yes sir.
SHO with a Master.
Like I said, a real Favorite circuit.  :icon_cool:

for the master volume, did you use a 100k pot instead of the 100k resistor at the output? (like the second stage of the super-duper? and if so, are you able to get some kind of clipping going?)

R.

The pot was 50K audio.
I would say some slight clipping......more of a "sheen" to the tone actually.
It's a real nice build.