Ibanez - SD-9 Sonic Distortion

Dirk_Hendrik · Post by **Dirk_Hendrik** » 14 May 2009, 17:00

BTW,
no flame intended but?
Who's asking?

basuramail · Post by **basuramail** » 14 May 2009, 19:06

Hi Dirk, cool thread here, I'm new in this forum and I'm trying to make my old Ibanez SD9 a little bit louder. Effect off ist louder as effect on with max volume.

B.

Dirk_Hendrik · Post by **Dirk_Hendrik** » 15 May 2009, 14:29

Some continued stuff here:
viewtopic.php?f=13&t=5663

Crimson · Post by **Crimson** » 17 May 2009, 09:16

I thinks i've some problems with my SD9...
It reacts very well to clean up the guitar volume, it's very "dynamic sensitive", but to have a distorted sound i have to set the gain at maximun, and it has not much gain in that position.
The main mods that i've made are on the gain pot (i use a 1meg instead of 250k and 10k res instead of 33K...I think with the 1meg i should have more gain than the stock one), i remove output buffer (maybe this is the problem?) and i'm not using the second op amp on the Vbias...could also this be a problem?

Crim

EDIT: schematic with mods added

popstudioguitar · Post by **popstudioguitar** » 15 Jun 2009, 22:37

It's been a while that I didn't check on that thread and....wow !

I need to thank you all...I've taken my GGG SD9 out of the closet and with the mods/ajustments to the real schemo..it's pretty damn close to the original !

Yeeeehaawwwwwww !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

candletears7 · Post by **candletears7** » 08 Aug 2009, 10:57

I've just seen this excellent thread, and thought i would post a link to another thread I posted here at FSB regarding an sd9 project im attemtping.
Any help very much appreciated. My skills may be lacking a little, but I will attempt to breadboard Dirk's schematic

. If anyone could help a fella out with the info below that would be great.

viewtopic.php?f=10&t=6916

popstudioguitar · Post by **popstudioguitar** » 14 Aug 2009, 01:42

Hey Candletears...have a look here: https://www.freestompboxes.org/viewtopic ... &hilit=sd9

You'll find a complete project for SD9.

Haven't tried it yet but sure it pretty good !

candletears7 · Post by **candletears7** » 14 Aug 2009, 05:33

Thanks mate, but I was lucky enough to have a brand new Maxon SD9 given to me. Of course I'm going to crack it open and have a go at upgrading some caps or modding it somewhere along the lines of what Analogman does. I need to do some research on this, but I wouldn't mind getting some more headroom out of it volume wise, or incorporating the Vance mods on the GGG site. Any tips on this...?

flow · Post by **flow** » 29 Sep 2009, 18:17

I built an SD-9 clone on a veroboard some years ago according to GGG’s schematic, which happens to be almost identical to the schematic drawn by Jack Orman btw (no pulldown resistors in the later one). I used a 4558 opamp, a 3904 transistor, metal film resistors and some basic film capacitors. The sound wasn’t "muddy or fuzzy" at all. Bass response was very balanced and tight and note articulation was good. I prefer darker tones so the sound was a bit too trebley sounding to my taste. That wasn’t a surprise to me since I had read about it in some reviews. Look at the settings as used by Landau and Henderson btw – The toneknob is at zero!

Now if you look at the "unverified schematic" posted by analogguru you’ll see it’s almost identical to the Muzique schematic (feedback loop connected to ground in the first one). Of course there are the output buffer and "the other extra" like there are in almost every FET-switched pedal. Finally if you look at the schematic that Dirk has drawn you’ll see it’s almost identical to the abovementioned schematics (two electrolytic caps have different values).

My conclusion is that all of the abovementioned versions are "correct" Sonic Distortions even though there are some minor (version) differencies. This unnecessary mystery and "it-sounds-totally-different"-attitude irritates me. Or to mystify more: did you know that some early SD-9s have Ge clipping diodes?

I think I have to put this circuit on a prototyping board and give it a new try. So to speak and mainly, "ormanize" the tone section.

Dirk_Hendrik · Post by **Dirk_Hendrik** » 29 Sep 2009, 21:16

flow wrote:I built an SD-9 clone on a veroboard some years ago according to GGG’s schematic, which happens to be almost identical to the schematic drawn by Jack Orman btw (no pulldown resistors in the later one). I used a 4558 opamp, a 3904 transistor, metal film resistors and some basic film capacitors. The sound wasn’t "muddy or fuzzy" at all. Bass response was very balanced and tight and note articulation was good. I prefer darker tones so the sound was a bit too trebley sounding to my taste. That wasn’t a surprise to me since I had read about it in some reviews. Look at the settings as used by Landau and Henderson btw – The toneknob is at zero!

Now if you look at the "unverified schematic" posted by analogguru you’ll see it’s almost identical to the Muzique schematic (feedback loop connected to ground in the first one). Of course there are the output buffer and "the other extra" like there are in almost every FET-switched pedal. Finally if you look at the schematic that Dirk has drawn you’ll see it’s almost identical to the abovementioned schematics (two electrolytic caps have different values).

My conclusion is that all of the abovementioned versions are "correct" Sonic Distortions even though there are some minor (version) differencies. This unnecessary mystery and "it-sounds-totally-different"-attitude irritates me. Or to mystify more: did you know that some early SD-9s have Ge clipping diodes?

I think I have to put this circuit on a prototyping board and give it a new try. So to speak and mainly, "ormanize" the tone section.

Got a new job and celebrated that... I have to dive into this tomorrow

flow · Post by **flow** » 30 Sep 2009, 05:44

Here are the schematics and the pictures I was referring to:

GGG's schematic: http://www.generalguitargadgets.com/dia ... nic_sc.gif
Jack Orman's schematic (Muzique): http://www.muzique.com/schem/sonic.gif
Schematic posted by analogguru: http://www.aronnelson.com/gallery/main. ... ewsIndex=1
Dirk Hendrik's schematic: http://www.dirk-hendrik.com/temp/sd9_clone.pdf
Mike Landau's pedalboard: https://i242.photobucket.com/albums/ff2 ... CF1628.jpg
Scott Henderson's pedalboard: http://www.scotthenderson.net/pedalnew01.jpg

Keep in mind that I’m not going to argue how much the switching circuit and the output buffer affect to the sound. My premise is that the first three stages: input buffer, opamp stage and the tone section are the most important blocks soundwise.

Somebody just had to see and hear the forest, not only the trees

Dirk_Hendrik · Post by **Dirk_Hendrik** » 30 Sep 2009, 13:34

flow wrote: My conclusion is that all of the abovementioned versions are "correct" Sonic Distortions even though there are some minor (version) differencies. This unnecessary mystery and "it-sounds-totally-different"-attitude irritates me. Or to mystify more: did you know that some early SD-9s have Ge clipping diodes?

Back and sober

Regarding those clipping diodes, doable but the first time I hear about it. Do you have something which confirms that?

Then,
Yep. I agree with you on the the tonally-attitude-thing. Especially since often these differences are pretty minor and can be dismissed completely when using that pedal on stage.

But I do not agee with you on 2 points, being 2 caps that both dramatically influence the sound when altered in large proportions. The first one is the 0.22uF cap that goes to ground through a 470 ohm resistor from the inverting input of the first opamp. Changing this value will alter the bass response, Making it 100 times larger changes the bass response to a point where the pedal will become very muddy and unusable.

The other one is the 0.47uF coupling cap going from the drive to the clipping stage. Again, a multiplication of a factor 100 will give such a bass response the sound will be over-muddy.

But, where does that error come from?
In most cases a builder will use standard film caps at these positions. When doing large volumes it does become considerably cheaper using electrolytics. Since one sees an electrolytic at those positions and electrolytics usually imply "1uF or larger" I still have the opinion the JD Sleep, Silkebakken and the Orman schematic are wrong on these 2 caps untill proven otherwise. This otherwise means the cap as well as the soldering for that cap. When it's original and untouched I'll be amazed.

But,
How come there's 3 that say the same and one (mine) is different?
I just went in again and reverified again. I cannot say anything for the Silkebakken schem but I suspect the JD Sleep is based on the Orman schematic.

Somebody needs to inspect that forest, and cut out the dead wood occasionally

flow · Post by **flow** » 30 Sep 2009, 19:33

Dirk_Hendrik wrote: Regarding those clipping diodes, doable but the first time I hear about it. Do you have something which confirms that?

Well, my "source" is a an old school DIYer from a finnish discussion forum. He has built and reverse engineered pedals a long time before the birth of Internet so he’s very qualified. His SD-9 is from the early 80’s. I take the freedom to quote and translate a piece from his reply to me: "I haven’t measured the corner voltage of the diodes, but externally they look the same than the diodes in my MXR Dist+. They’re colourless and see-through and the cathode side is marked with a black circle. There aren’t any text or other markings on the diodes. Externally the diodes look totally different than the diodes in my original TS-9 (quite sure from ’82). So based on the external comparisons I suppose the diodes are germaniums (1N34). The corner voltage measurement would confirm the matter."

But I do not agee with you on 2 points, being 2 caps that both dramatically influence the sound when altered in large proportions. The first one is the 0.22uF cap that goes to ground through a 470 ohm resistor from the inverting input of the first opamp. Changing this value will alter the bass response, Making it 100 times larger changes the bass response to a point where the pedal will become very muddy and unusable.

The other one is the 0.47uF coupling cap going from the drive to the clipping stage. Again, a multiplication of a factor 100 will give such a bass response the sound will be over-muddy.

You have to look and analyze the filtering as an entirety, stage by stage, and not only stare at a single stage. This is a trap to which even some of the older and more experienced DIYers seem to fall into. With a 22 uF capacitor the corner frequency of the high pass filter is 15 Hz and after the opamp with a 47 uF capacitor the corresponding number is 1,5 Hz. If one stares at these numbers only things may seem "a bit" muddy. But that’s not the whole picture - The high pass filter side of the BMP-style tone stack "cuts the shit away" (a saying I’ve borrowed from an old sound engineer) below 867 Hz. This was of course only a rough analysis but you got the point.

And like I said before the real life experience was that "the bass response was very balanced and tight and note articulation good". I could even say that it is desirable that the clippers are getting more low frequencies but I won’t; it is a matter of taste

Somebody needs to inspect that forest, and cut out the dead wood occasionally

I appreciate your hard work so a hat tip to you mister forester! To me the dead standing trees are the salt and soul of a forest

clubsprint · Post by **clubsprint** » 12 Nov 2009, 12:18

umutgokcen wrote:I have an original SD9 so I thought I'd chime in. I had it modded by Analogman some years ago which reduced the mid-scoopiness and made the tone knob have more useful range. He doesn't really give much details on how he achieves that and at the time I didn't know anything about circuits so I'm afraid I can't tell you what he changed in there. The bottom line is it sounds really good!

Lately, I decided to try out a few different op-amp chips in the SD9 and the one I liked best turned out to be the TL072. It definitely sounds less compressed than the JRC4558, and that takes the pedal further away from Tube Screamer territory (which I prefer). I think the top end is also a bit clearer (but not harsher) with the TL072.

I had some samples of it on my computer so you can hear what I'm talking about. There are 3 files; one with drive turned down another with drive up, and then both together with a drum loop. I play a few bars with the clean sound in the beginning to give you some point of reference.

Does anyone have amy ideas what the Analogman modifications are.

Mark

clubsprint · Post by **clubsprint** » 01 Feb 2010, 07:30

I'm looking at building a clone of the SD-9 without the FET switching but I've got a dilemma. I gathered a few schematics
from the web but they all seem slightly different. Consequently I'm full of questions.
Firstly does dropping the buffer from the output stage make much difference and is it
going to effect it's interaction with other pedals?
I'll use the numbering scheme from the JD Sleep Schematic (ggg_maxxon_sonicdistortion_sd9.pdf). I tend to trust Dirk's schem as being the closest to the original (ibanez_sonic_distortion.pdf).
Why add a 2M2 R19 across the input.Wont this alter the sound of the pedal?
Should R7 be 33K or 3K3?
Should C5 be 1nF or 220pF
Should C3 be 220nF or 22uF
Is 470 correct for R5
Should C6 470nF or 47uF
One of the schems has modifications for Tone (C8 from 0.1uf to .047uF) and second part of opamp for "volume recovery".
Is this similar to the A/Man mods. Is this mod even desirable of necessary?

Schems at
http://clubsprint.250free.com/SD9/ibane ... icdist.pdf
http://clubsprint.250free.com/SD9/ibane ... ortion.pdf
http://clubsprint.250free.com/SD9/rdv_sd9_sc.gif
http://clubsprint.250free.com/SD9/sd_9.jpg
http://clubsprint.250free.com/SD9/ggg_m ... on_sd9.pdf

Regards
Mark

Dirk_Hendrik · Post by **Dirk_Hendrik** » 01 Feb 2010, 07:49

Take mine as correct and forget the others.

Also, do a search on this forum. There was plenty written around last april/may.

soulsonic · Post by **soulsonic** » 10 Jun 2010, 04:35

I have an Analogman modded SD-9 here that I need to repair for a friend. The bypass isn't working correctly. The "super" mod doesn't appear to be anything more than changing the resistor and cap of the high-pass filter side of the tone control from 6k8 and 27n to 27k and 100n.
Not much of a mod...

And the 220nF is definitely the value of the cap to ground in the feedback loop in this one, and it appears to be the stock tantalum. And the series cap before the clipping diodes is a 470n electrolytic, which also looks stock. The only difference I see from Dirk's schematic is that the output cap is 10uF instead of 1uF. That cap also looks stock, as it matches the other electros.

candletears7 · Post by **candletears7** » 12 Jun 2010, 08:22

Good on ya man! Thanks for that little tip.

I since sold the SD-9, but I may come back to a vero build. My breadboarding has come a long way and I could confidently build this circuit and futz about with the mids now.

extremist · Post by **extremist** » 23 Jun 2010, 19:48

Hello guys. I happen to have an original Maxon SD-9 here today. A friend of mine asked to build him a clone in a small light enclosure (B), because the original is just to heavy and he doesn't like the switch. His SD-9 sounds slightly different compared to my GGG SD-9 modded to Dirk Hendrik's specifications (220p -> 1000p, 47u -> 0.47, 22u -> .22, volume pot a50k -> b100k). It's louder and has more meat. It has some unknown diodes (unmarked, red with white band) and looks true bypass. All pots are linear: Level - 100k, Tone - 20k, Dist - 250k. Maybe i'll be able to trace it, but not sure of my skills. Here are the guts shots.

extremist · Post by **extremist** » 23 Jun 2010, 22:01

did some photoshoping

Ibanez - SD-9 Sonic Distortion [schematic]