My first mod! Boss SD-1

[fjdenigris]

Well, I modded an SD1 and it's cool! It sounds much better than stock, but I still like my Analog Man SD1 Silver modded one better. I have not opened it up to see what he did, I wanted to go by all the info here and see if I could pick and choose from the mods you all did to get one that I would like. I did compare it to another stock SD1 and it blows it away, but the AM one is much nicer sounding -more full and high fidelity sounding.

I used Mike's Silver modded one for general OD/rhythm work last night and had mine set for lower OD and as a boost into the other. Cascaded they sounded really good, it made the gig a lot of fun!! I had three people checking out my pedal board last night, and one guy who has an SD1 said he used it sparingly opting for his amp's gain channel for OD. He'll be sending it out to Analog Man now after recommending him. He loved the way mine sounded too, it was great to be able to say, "Yeah, I modded this one...."   Here's what I did (so far!):

Component #, original value, changed to:

- C2,  .018 > .1uf metal film
- C3,  .047 > .047uf metal film
- C6    - removed
- C7,  1/50 radial cap > 1uf metal film (box 105 type)
- C8,  .047 > .1uf metal film
- C10, 1/50 radial cap > 1uf metal film (box 105 type)
- R1,  10k > 10k carbon composition
- R2,  470k > 1m
- R7,  10k > 10k carbon composition
- R17, 100k > 10k carbon composition
- D4,  1N914? > 1N4001
- D5,  1N914? > 1N4001
- D6,  1N914? > 1N34A


Should any of the transistors need to be changed out, will that help with noise or fidelity at all?I imagine I'll have to get some sockets and try different opamps and diodes too.

I posted another thread in the "Schematics and Layouts thread", it seems like few people go over there. I wondered in the other thread if we could have a place to complie all of our mods for easiest viewing.
http://www.elixant.com/~stompbox/smfforum/index.php?topic=40181.0

[fjdenigris]

Bump?

[Khas Evets]

If your going for high fidelity, why are you using carbon comp resistors? I would have gone with metal film.

[fjdenigris]

Good question, mojo factor? I noticed that there was a post with Keeley's mod showing the blue metal film ones. Is there a difference between the blue ones and the brown ones?

[Melanhead]

SD-1s are great to Mod as they're so cheap! ... I bought 4 of 'em a while back and modded them all differently, sold 'em off though. ... I'm not really a believer in the carbon comp resistors though as all they seems to do is add noise ... although there are many opinions on 'em and to each his own.

as far as op-amps are concerned, I haven't heard much of a difference from the Burr Brown to the various 4558's available... I usually use the TI RC4558P because I have a bunch of 'em.

socket and try but don't expect night and day results.

[wampcat1]

SD-1s are great to Mod as they're so cheap! ... I bought 4 of 'em a while back and modded them all differently, sold 'em off though. ... I'm not really a believer in the carbon comp resistors though as all they seems to do is add noise ... although there are many opinions on 'em and to each his own.

as far as op-amps are concerned, I haven't heard much of a difference from the Burr Brown to the various 4558's available... I usually use the TI RC4558P because I have a bunch of 'em.

socket and try but don't expect night and day results.

Yep!
(We need a thumbs up icon  )

[fjdenigris]

I love modding too! I've built several pedals, but modding is fun and cheap! Let see, I've built the "Tweak-O", the Orange Squeezer and the Orange Sunshine. I've tried a few on a breadboard too. Fun stuff!!

I'll be building a Tube Screamer next, but what to mod next? Hmmm...

Oh yeah, it's addicting!! 

[Melanhead]

I love modding too! I've built several pedals, but modding is fun and cheap! Let see, I've built the "Tweak-O", the Orange Squeezer and the Orange Sunshine. I've tried a few on a breadboard too. Fun stuff!!

I'll be building a Tube Screamer next, but what to mod next? Hmmm...

Oh yeah, it's addicting!! 

It's addictive! ...

[Xavier]

I love modding too! I've built several pedals, but modding is fun and cheap! Let see, I've built the "Tweak-O", the Orange Squeezer and the Orange Sunshine. I've tried a few on a breadboard too. Fun stuff!!

I'll be building a Tube Screamer next, but what to mod next? Hmmm...

Oh yeah, it's addicting!! 

It's addictive! ...

Addictive you say? It's much, much worse than that . I also started modding and that is not satisfying anymore. Building (I should say cloning) is far more addictive. I guess the next step is designing my own effects, but that's a completely different story.

+1 on the opamps. I have an OPA2134 in my OD1 clone and I think I'm going back to the old 4558. I can't recall who said that the low slew rates sounded better, but I think some of the shrillness of my OD1 comes from the opamp. I've done severalt blind tests and until now I wasn't able to tell the dufference

[vanhansen]

I'd like to chime in and say, heck yeah it's addictive. I think I need to revisit my SD-1 though.  Ever since I acquired a MXR Wylde OD, that's all I've been using in front of my amp.  Either that or a booster.  It's one to make a circuit, it's another to mod it, or tweak it.  It is fun tweaking them, especially when there's something on the breadboard.

All my mods came from Fuzz Central.  I did the changes he had listed, except for the diode change.  Big improvement.  I do notice a change between the stock chip and the Burr Brown though.  The Burr Brown seemed to warm it up some.  Not so harsh anymore.

[Melanhead]

I love modding too! I've built several pedals, but modding is fun and cheap! Let see, I've built the "Tweak-O", the Orange Squeezer and the Orange Sunshine. I've tried a few on a breadboard too. Fun stuff!!

I'll be building a Tube Screamer next, but what to mod next? Hmmm...

Oh yeah, it's addicting!! 

It's addictive! ...

I guess the next step is designing my own effects, but that's a completely different story.

That's where I'm at if you read my other post ... it's not easy to get something a bit different 

[Xavier]

I agree, specially if all the "new" designs revolve around the "ideal" fuzz/boost/OD/dist pedal. I think everything has been said already and there's very little else to add, other than different diode combos either to ground or FB, and different opamps.

Being a big fan of chorus pedals, I'd like to design something in the lines of the old tri stereo chorus, but that would require far more knowledge than what I currently have.

Oh well, I'm drawing a vero layout for the Grandlaff Mydanic Odee . If there's more than 2 opamps involved I'm lost....

[Melanhead]

I agree, specially if all the "new" designs revolve around the "ideal" fuzz/boost/OD/dist pedal. I think everything has been said already and there's very little else to add, other than different diode combos either to ground or FB, and different opamps.

Being a big fan of chorus pedals, I'd like to design something in the lines of the old tri stereo chorus, but that would require far more knowledge than what I currently have.

Oh well, I'm drawing a vero layout for the Grandlaff Mydanic Odee . If there's more than 2 opamps involved I'm lost....

Yup! ... I'm with you there! ...

[fjdenigris]

It's like trying to invent a new mode of transportation, almost everything has been thought of already! You can improve on what we have, be innovative and totally rethink an effect, etc., but coming up with a totally new effect would to be a major breakthrough.

[wampcat1]

I agree, specially if all the "new" designs revolve around the "ideal" fuzz/boost/OD/dist pedal. I think everything has been said already and there's very little else to add, other than different diode combos either to ground or FB, and different opamps.

Being a big fan of chorus pedals, I'd like to design something in the lines of the old tri stereo chorus, but that would require far more knowledge than what I currently have.

Oh well, I'm drawing a vero layout for the Grandlaff Mydanic Odee . If there's more than 2 opamps involved I'm lost....

http://www.indyguitarist.com/torchy/Distortion_Overdrive/Tubescreamer/screamer.GIF

[Xavier]

I agree, specially if all the "new" designs revolve around the "ideal" fuzz/boost/OD/dist pedal. I think everything has been said already and there's very little else to add, other than different diode combos either to ground or FB, and different opamps.

Being a big fan of chorus pedals, I'd like to design something in the lines of the old tri stereo chorus, but that would require far more knowledge than what I currently have.

Oh well, I'm drawing a vero layout for the Grandlaff Mydanic Odee . If there's more than 2 opamps involved I'm lost....

http://www.indyguitarist.com/torchy/Distortion_Overdrive/Tubescreamer/screamer.GIF

I can't believe it's the same exact schematic, is it?

[Melanhead]

I agree, specially if all the "new" designs revolve around the "ideal" fuzz/boost/OD/dist pedal. I think everything has been said already and there's very little else to add, other than different diode combos either to ground or FB, and different opamps.

Being a big fan of chorus pedals, I'd like to design something in the lines of the old tri stereo chorus, but that would require far more knowledge than what I currently have.

Oh well, I'm drawing a vero layout for the Grandlaff Mydanic Odee . If there's more than 2 opamps involved I'm lost....

http://www.indyguitarist.com/torchy/Distortion_Overdrive/Tubescreamer/screamer.GIF

I can't believe it's the same exact schematic, is it?

Same layout basically with some values changed ...