Maxon SD-9 Clone

[duhvoodooman]

Here are a few pics of a pedal I'm building for Tone2TheBone based upon the excellent (just ask Mr. Renman!) Maxon SD-9 "Sonic Distortion" circuit. Since nobody seems to make a full kit, I had to go with a PCB from General Guitar Gadgets and then order all the required parts "a la carte" from Mouser and Pedal Parts Plus, based upon the bill of materials posted on the GGG website.

It's actually quite a simple circuit, using a dual opamp for the gain and the ubiquitous 1N914 silicon diode pair for signal clipping. The tone control is rather unusual vs. most OD/distortion pedals in that it contains both high and low boost/cut circuits to give a wider range of control. The PCB shot below shows how relatively simple this pedal circuit is. It has volume, tone and distortion (gain) controls, like many OD/distro boxes. The 3PDT switch is wired for true bypass.

Of course, I couldn't just build it stock now, could I? That twisted pair of wires coming off the PCB go to a DPDT toggle switching between the stock 1N914 clippers and a pair of red LED's for a "turbo" clipping mode. Flipping the switch to the LED's gives a louder, fatter and somewhat clearer distortion tone.

Also shown are photos of the assembled pedal, one from the top and the other a "gut shot". I labeled the latter to show 3 features:

1. That resistor hanging out there is just a 4.7 Kohm to reduce voltage through the power LED. The GGG board doesn't have a spot for the LED resistor, so that's where I attached it, to another resistor leg at the upper end of the +9V trace. It's then soldered to one leg of the LED, and the other leg is wired down to the 3PDT switch.
2. The familiar (to you TS aficionados, at least) JRC4558D opamp. I used an opamp socket on the board, so Tone can mix & match IC's to his little heart's content.
3. The clipper switch. You can see the pair of water-white red LED's at the bottom, and the pair of 1N914's is mostly obscured by the purple wire at the top of the switch. Those purple wires attach to the board where the 1N914's would normallly be located in a stock build.

BTW, I've dubbed the pedal "Sonic Tonic". A mock-up of the decaled enclosure is included below, to give an idea of what the finished pedal will look like.

More pics and comments re: how the pedal performs to follow....

 

[Robert]

Whoa, way cool! You da man VDM!

Sonic Tonic...

Now you will get many requests....

 

[tunghaichuan]

Love that color. Excellent work.

tung

 

[Tone2TheBone]

I love that Joker color scheme. Lime green and purple yeahhh. I can't wait to get my hands on this Voo.

 

[Spudman]

That looks cool and is way tempting to me too but...I wanted to ask you a question.

Why don't you put the AC jack at the top of the pedal? It's a PITA to get extra AC cable to make the reach to the lower right when all the other pedals have the jack at the top. It would make chaining AC to peals much easier.

 

[duhvoodooman]

Why don't you put the AC jack at the top of the pedal? It's a PITA to get extra AC cable to make the reach to the lower right when all the other pedals have the jack at the top. It would make chaining AC to peals much easier.

That could indeed be done. The issue is that I generally try to buy predrilled enclosures and they all come with the AC jack hole drilled on the side. I can purchase undrilled enclosures (I have to do this with the ZYS, because of its unique layout) and drill them myself, but that means a lot of extra time/effort measuring, marking & drilling, and time = money, as they say. I'd have to charge more, to make it worth that extra time. But it can definitely be done.

 

[duhvoodooman]

Decaled enclosure:

 

[Tone2TheBone]

You've got a good eye Voo. I could never align a waterslide as straight as that.

 

[duhvoodooman]

Pics of the finished "Sonic Tonic" SD-9 clone, inside and out:

Here's a link to a quick demo clip. Recorded with the UK'70's model of my AD30VT. Only additional effect, other than the SD-9, is a bit of reverb. The SD-9 is set to the "normal" (i.e. stock) clipping mode throughout.

http://www.box.net/shared/iz9ir72iyv​

The first half of the clip is recorded with my LP Std on the bridge pickup. The same chord sequence is played through 3 times:

• Clean
• SD-9, gain at 65%, tone 50% (mid-point)
• SD-9, gain at 65%, tone 65% (i.e. treble up, bass down a bit)

The first half ends with a single note sequence up in the middle of the neck, gain = 65%, tone = 50%.

The second half of the clip repeats this same series of 4 sequences, but played with my Xaviere XV870 Strat copy on the middle pickup. Same amp setup.

The apparent muddiness, most noticeable with the Strat chord sequences, is a function of the recording, not the actual pedal-guitar-amp output. It didn't sound muddy sitting here playing/recording it, so I apologize for that. I'm a better pedal builder than studio technician....or guitarist, for that matter! But I think you can get some idea of the big-bottomed roar this pedal puts out. Good midrange and tope-end definition for soloing, too. Very impressive pedal. Tone, ya done good pickin' out this one! :AOK: :dude: :rockon:

 

[Robert]

Hey, it was all because of me that Tone got interested in the SD-9! Right, Tone?

How exact of a copy is this to the Maxon SD-9 then?

 

[duhvoodooman]

Hey, it was all because of me that Tone got interested in the SD-9! Right, Tone?

Yup, that's right, Robert. It's all about you! :whatever:

How exact of a copy is this to the Maxon SD-9 then?

It's supposed to be identical to the vintage SD-9 circuit except for being true bypass, having pull-down resistors (prevent on-off "pop" but don't affect tone at all), and readily available pot values. And the "turbo" switch is my own modification. "Normal" is the stock SD-9 clipping mode.

 

[sunvalleylaw]

Another cool one! I wonder what that would sound with in combination with the v.2 Mouse, kinda like when I use the Bad Monkey and the DS-1 together.

 

[duhvoodooman]

I wonder what that would sound with in combination with the v.2 Mouse, kinda like when I use the Bad Monkey and the DS-1 together.

My personal experience is that running two high-gain pedals in series rarely sounds very good. At some point, all that gain & associated distortion & harmonics just become a chaotic sonic mess. But if you back off the gain oneither or both, who knows? Could be some useful tones there, I suppose....

 

[Tone2TheBone]

Good thing the post office is near my office cause I'll be checking it everyday until I get it!

 

[Tone2TheBone]

Just got my Sonic Tonic today. Messed with it some for lunch but I need to sit down and see what this sucker can do. Pedal was WELL PACKAGED Voo and looks absolutely killer. More to come.....

 

[Algonquin]

Looks like another beautifully built pedal DVM... everything looks incredibly neat and tidy!

Congrats Tone, I have no doubts you've got a keeper :AOK:

Awesome.

 

[Tone2TheBone]

Ok I seriously plan on posting another clip this time with my new Sonic Tonic - Maxon SD-9 clone that Duhvoodooman created for me. I'll also post more comments along with the vid. I've just been playing it all week and learning what it does. My discoveries need to be shared cause this is one hell of a pedal....again more to come....

 

[SuperSwede]

Ok I seriously plan on posting another clip this time with my new Sonic Tonic - Maxon SD-9 clone that Duhvoodooman created for me. I'll also post more comments along with the vid. I've just been playing it all week and learning what it does. My discoveries need to be shared cause this is one hell of a pedal....again more to come....

+1

I´m looking forward to hear (and watch?) the results!

 

[duhvoodooman]

VIDEO!! VIDEO!! VIDEO!! VIDEO!! VIDEO!! VIDEO!! VIDEO!! oke: :dude: :rockon:

 

[Tone2TheBone]

You asked for it...you got it...Toyota.

Actually more like Toy without the ota. In this case it's the brand spanking new Sonic Tonic video(s).

First vid is played with my Classic 50s Stratocaster. Amp used for both vids is my BillM modded Fender Blues Junior. Amp settings were...

reverb - 4
master volume - between 6 and 7
middle - 3
bass - 10
treble - between 8 and 9
preamp volume - 5

Knobs on the Blues Juniors go to 12.

Pedal settings for the Strat clip were...

level - 9:00
tone - 12:00
distortion - 9:00

I usually roll back my volume knobs on my guitars always so I had it rolled back to about 7 or so then increased them with a roll of the pinky finger at some parts. You can tell on the parts that get louder with more edge. Also disregard the comment at the beginning because I was actually using the neck and middle pickups and not just the middle. I switched up to the neck at the end.



Amp settings for the Les Paul vid were the same as the Strat.

Pedal settings were slightly different just added more gain...

level - 9:00
tone - 12:00
distortion - 12:00

Again my volume knob on the Les Paul was rolled back to give me that tight low end crunch. In fact I think I left it that way for the entire clip without turning it up. Turned up full you get this juicy hairy tone as the pedal implies on it's enclosure (Thanks Voodoo). Sustains for days and sounds mahvelous. This is truly a world class distortion unit and I am very pleased with the results. I purposely played the demo on my Blues Junior because I wanted people to hear how solid the amp sounds especially with this pedal. If I would have used the Marshall the effect might not have been as dramatic. It might have been misconstrued as just another crunchy Marshall vid.

Duhvoodooman was kind enough to supply a modification to the stock design by adding that mini toggle switch and set of LEDs for the "turbo" mode and I absolutely LOVE using that mode when the amp is already breaking up. Holy moley! Once again thank you Bob for creating these masterpieces!!!

 

[Robert]

Sounds awesome! On the first clip, it almost sounds like you are using a compressor pedal. Is that the video camera doing that or does the amp/pedal combination sound that compressed?

 

[duhvoodooman]

Wow, those sound great, Tone! Really liked both of 'em. Love the Marshall tone with the LP, and the Strat sounds really good, too. Especially liked how the high notes screamed when you really dug in. Guess you can get screaming solos with that amph--with the right pedal, of course!! :AOK: :dude: :rockon: :bravo:

 

[Tone2TheBone]

Sounds awesome! On the first clip, it almost sounds like you are using a compressor pedal. Is that the video camera doing that or does the amp/pedal combination sound that compressed?

Rob - It's gotta be the amp and the pedal combo. When pushed loud the Blues Junior's diminutive cabinet design slightly compresses your tone. The pedal is hitting it harder too. When played at lower apartment volumes it isn't as rich in tone. The Sonic Tonic just slays with this amp and you can guess how good it sounds on the Jubilee. I could have used more gain on the Strat clip but I wanted to show how good it is as an overdrive. As I mentioned I barely had the distortion knob set at 9:00 using the Strat and at 12:00 on the Les Paul clip. I can push the gain higher if I wanted to but this pedal has so much gain I don't really have to. It's especially more noticeable on the Les Paul. Anymore gain than 12:00 and it's over the top which can be a good thing! I wanted to show that you didn't really need all that much gain to make it sound cool. But if you want more it's got PLENTY.

Voo - I knew you'd appreciate the Les Paul clip. I think it shows how tight the bottom end can be and of course how much gain the pedal provides. I seldom ever turn it past noon unless I'm using the Goldtop with P90s. It's very versatile because you have so much leeway on how much distortion and tone you want. It's not a one trick pony at all and that "turbo" switch is the icing on the cake my friend. :beer:

 

[Algonquin]

Beautiful pedal buld DVM... and way to make it sing Tone :AOK:

 

[sunvalleylaw]

Tone, buddy, awesome clips! Thanks for posting. I like both sounds really well. I sure am a strat addict, and love that combo, but like that down and dirty LP sound too. It is nice to hear you again!

EDIT: Ok, I'll ask. Can you do one with the Jubilee too? I love that amph and would love to hear what the pedal does to it. :rockon:

 

[Tone2TheBone]

Tone, buddy, awesome clips! Thanks for posting. I like both sounds really well. I sure am a strat addict, and love that combo, but like that down and dirty LP sound too. It is nice to hear you again!

EDIT: Ok, I'll ask. Can you do one with the Jubilee too? I love that amph and would love to hear what the pedal does to it. :rockon:

Thanks. Sure I can do one with the Marshall. I think this time I'll do one in turbo LED mode with the amp already dirty. You gotta hear that combo. *whistles*