Boss SD-1 "Bleed Fix" easier fix solved?

[soupbone]

Me and a friend were working on a easier way to do the "Bleed Fix" mod for the Boss Super Overdive.I just need some confirmation that this will work?Here's the schematic; http://www.hobby-hour.com/electronics/s/schematics/boss-sd1-super-overdrive.gif  Here's what we did;You take R1 (10k) out and solder the brown wire coming from pad 3 to the bottom hole of R1.The brown wire is glued to the input jack.You take a 10k resistor and solder one end to the brown wire,and the other end of the resistor to the input jack sleeve(ground).Here's some pic's of what it looks like; http://s1143.beta.photobucket.com/user/soupbone71/library/Boss%20SD-1%20Bleed%20Fix?page=1  Not hearing any background noise coming through now.Fixed?Possibly? 

[slacker]

I must be missing something, as far as I can see if you do what you say you shouldn't get any sound at all. If you take out R1 how does the signal get from the input jack to the first transistor?

[soupbone]

I must be missing something, as far as I can see if you do what you say you shouldn't get any sound at all. If you take out R1 how does the signal get from the input jack to the first transistor?

I don't really know!lol The pedal works fine after the mod though.No more bleed through that i can tell.R1 is a 10k resistor.Just solder a 10k resistor(the same value resistor as R1) to the brown wire,where it's glued to the input jack(you have to cut it).The other end of the resistor goes to the "ring",not the "sleeve"( i think?) on the input jack.The other end of the brown wire that was de-soldered from pad 3 on the pcb,To the bottom of where the resistor was taken out.(i.e. right above the .047 cap.) Don't know if that helps or not!

[soupbone]

Here's some more gutshot's of the "Modded SD-1" and an Un-Modded SD-1". http://s1143.beta.photobucket.com/user/soupbone71/library/Boss%20Super%20Overdrive%20Modded%20and%20Un-Modded%20pics?page=1  I feel like an idiot about which is the tip,ring and sleeve on this boss input jack!   The Un-Modded pic,the brown wire coming from pad 3 on the pcb,is going to the bottom lug on the jack.The lug right above that one has a black wire going to the battery snap,and a yellow wire going to pad 10.The lug closest to the chassis has one black wire coming from it going to pad 16 on the pcb.Just need some help identifying those 3!

[soupbone]

Here's some more gutshot's of the "Modded SD-1" and an Un-Modded SD-1". http://s1143.beta.photobucket.com/user/soupbone71/library/Boss%20Super%20Overdrive%20Modded%20and%20Un-Modded%20pics?page=1  I feel like an idiot about which is the tip,ring and sleeve on this boss input jack!  The Un-Modded pic,the brown wire coming from pad 3 on the pcb,is going to the bottom lug on the jack.The lug right above that one has a black wire going to the battery snap,and a yellow wire going to pad 10.The lug closest to the chassis has one black wire coming from it going to pad 16 on the pcb.Just need some help identifying those 3!

crap

[soupbone]

Anybody?

[soupbone]

Ok,My  friend  that  knows  way  more  than  i  do  at  electronics  showed  me  using  a  guitar cord and  a  meter  how  to  figure  out  which  was  the  tip,ring,and  sleeve.So,The  brown  wire  coming   from  the  tip  needs  to  be  cut.Solder  one  end  of  a  10k  resitor  to  the  end  of  the  brown  wire.Solder  the  other  end  of  the  resitor  to  the  tip  of  the  input  jack.Read  some  of  the  earlier  comments  on  how  to  do  the  other  part.My  electronics  buddy  said  it  makes  total  sense.He  told  me  how,but  i  went  way  over  my  head. lol  So,Do  you  peoples  think  this  will  work?

[slacker]

Any chance you can draw your changes on the schematic? I still can't understand what you're actually doing.

[rosssurf]

I am wanting to fix the bleed in mine as well. Still following this to see.   Bump

[soupbone]

Any chance you can draw your changes on the schematic? I still can't understand what you're actually doing.

[soupbone]

Never got a concrete answer to if this will work?There's some pic's I posted of the mod close to the top of the page.Sorry for posting one my old thread.

[Quackzed]

ok, so it seems like what you did is to take the 10k that is between the input jack 3 and c1 and remove it, moving the brown wire to the other side of r1, so it goes from input 3 to c1 without the 10k, then use the 10k to go between the in jack 3 and ground. this puts 10k to ground at the input.not sure but it could fix any bleed if the bleed is coming from the input.not sure why there would be bleedthrough at all tho...

[soupbone]

ok, so it seems like what you did is to take the 10k that is between the input jack 3 and c1 and remove it, moving the brown wire to the other side of r1, so it goes from input 3 to c1 without the 10k, then use the 10k to go between the in jack 3 and ground. this puts 10k to ground at the input.not sure but it could fix any bleed if the bleed is coming from the input.not sure why there would be bleedthrough at all tho...

So,in your estimation,this will work?Thanks for your help!

[shredgd]

Soupbone, it is still not clear wether you added a 10k resistor from signal to ground at the input of the pedal (but this would eat a lot of signal, so I guess you just messed up words between "tip" and "sleeve"), or you simply "exteriorized" the 10k resistor from the board to "flying". In the latter case, I really doubt that can be helpful.

HOWEVER, this well known issue of the SD-1 has already been SOLVED exactly 9 years ago (!!) by ANALOGGURU.
You can read here (http://www.diystompboxes.com/smfforum/index.php?topic=23903.0) the thread I started that long time ago, where I put down in words all the dozens of experiments and substitutions I tried in vain, before concluding we probably are/were experiencing a layout issue and, most of all, before analogguru posted a schematic of his really clever solution (page 3 of the thread). Now, that schematic appears to be no longer available, but in the subsequent posts I put it down in words for another person, so here you have it (quoting myself):

"You need an SK30A jfet, a 0.1u (=100n) cap and a 1n4148 diode.
Obviously, you have to solder your new components to the top side of the board, because you won't be able to close your pedal anymore if you work on the traces side...!
Watching the front (the flat side) of the jfet, the three legs pointing downwards are named (from left to right) S, G and D (Source, Gate and Drain, respectively).
Yuo have to solder S to D4's cathode (the side with the black ring), G to your new 1n4148's anode (the side without the black ring) and D to one side of the cap.
The other side of the cap must be soldered to the point where R5 and R6 "look each other" (they are connected together at that side, so it doesn't matter if you solder to R5's or R6's leg, choose one!).
Solder the cathode (again, the side with the black ring) of your new 1n4148 to the cathode of D8.
Done!"

This mod takes advantage of the existing switching circuit of the pedal and adds another function to it: lowering the gain of the overdrive to unity while bypassed (you might in fact have noticed that the bleed-through is more evident with the gain of the pedal left at max). By doing so, you don't get any hearable bleed-through (as any eventual bleed would be a clean signal, which we don't care about).

Hope this helps!

Giulio

[soupbone]

Soupbone, it is still not clear wether you added a 10k resistor from signal to ground at the input of the pedal (but this would eat a lot of signal, so I guess you just messed up words between "tip" and "sleeve"), or you simply "exteriorized" the 10k resistor from the board to "flying". In the latter case, I really doubt that can be helpful.

HOWEVER, this well known issue of the SD-1 has already been SOLVED exactly 9 years ago (!!) by ANALOGGURU.
You can read here (http://www.diystompboxes.com/smfforum/index.php?topic=23903.0) the thread I started that long time ago, where I put down in words all the dozens of experiments and substitutions I tried in vain, before concluding we probably are/were experiencing a layout issue and, most of all, before analogguru posted a schematic of his really clever solution (page 3 of the thread). Now, that schematic appears to be no longer available, but in the subsequent posts I put it down in words for another person, so here you have it (quoting myself):
"You need an SK30A jfet, a 0.1u (=100n) cap and a 1n4148 diode.
Obviously, you have to solder your new components to the top side of the board, because you won't be able to close your pedal anymore if you work on the traces side...!
Watching the front (the flat side) of the jfet, the three legs pointing downwards are named (from left to right) S, G and D (Source, Gate and Drain, respectively).
Yuo have to solder S to D4's cathode (the side with the black ring), G to your new 1n4148's anode (the side without the black ring) and D to one side of the cap.
The other side of the cap must be soldered to the point where R5 and R6 "look each other" (they are connected together at that side, so it doesn't matter if you solder to R5's or R6's leg, choose one!).
Solder the cathode (again, the side with the black ring) of your new 1n4148 to the cathode of D8.
Done!"

This mod takes advantage of the existing switching circuit of the pedal and adds another function to it: lowering the gain of the overdrive to unity while bypassed (you might in fact have noticed that the bleed-through is more evident with the gain of the pedal left at max). By doing so, you don't get any hearable bleed-through (as any eventual bleed would be a clean signal, which we don't care about).

Hope this helps!

Giulio

Thanks!I also found a "Bleed Fix Mod" by Brian Wampler(Indyguitarist) He used  J201+.1uf+1N4148.I've never tried it,so not sure if it works or not?Thank you for your help!-s.b.

[wampcat1]

Here's a diagram of it in case anyone is interested. Super simple mod. http://brianwampler.com/downloads/boss-sd1-bleed-fix.pdf

[rosscocean]

Did anyone ever get to the bottom of this? Other than the wampler/ old analog man mod that involves the floating fet?

[Groovenut]

Did anyone ever get to the bottom of this? Other than the wampler/ old analog man mod that involves the floating fet?

You can try this one. It only adds one new part to the original circuit. Though myself I would put the source towards R3 instead of towards the cap, since it's the source voltage that the Vgs references for turn off. YMMV

[rosscocean]

I'm not sure what you mean by "this one"?

[Groovenut]

Did anyone ever get to the bottom of this? Other than the wampler/ old analog man mod that involves the floating fet?

You can try this one. It only adds one new part to the original circuit. Though myself I would put the source towards R3 instead of towards the cap, since it's the source voltage that the Vgs references for turn off. YMMV

Oops!

My apologies.... forgot the link

Here you go!

https://sites.google.com/site/cctsim/home/boss-sd-1-bleed-fix