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ChristoMephisto
Platinum Member
Canada
1288 Posts |
 Posted - 01/19/2008 : 21:35:32
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Has anyone seen this mod before?
http://www.erikhansen.net/?page_id=91
Spent about an hour last week coming up with the same thing
only to find it was posted not too long ago |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 01/20/2008 : 10:21:43
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Hi Christo
This was one of my rainy day winter projects(it's summer over here)
I have been thinking about this for a while, you beat me to it.
How does it sound?
BTW, I managed to get my hands on six UA3403 quad op-amps, 1979 week 34 or 39 stock ,
like the ones used in the original version A of the OD-1's
I believe Roland used the RCA versions, of the 3403, but it's all from the same era.
Regards Dr. Bob |
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 01/20/2008 : 16:30:42
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Haven't had a chance to try it. Need another SD-1 before I try it.
Learned my lesson last time I modded my SD-1, and missed the original sound from it. Got one thats 22 years old now, and love it.
On the look out for a new one, good thing their plentiful, and way less in cost than an original OD-1.
About time too, why were every other mod for a TS or a Foolsclone, why not mod it a good classic
Was thinking about what to do with the tone knob. Came up with changing it to a high band pass before the clipping at R4. Wiring up a 82k resistor and the 20k pot in series. Crank the Tone knob, and its the OD-1 sound, back it off for a tad less bass 338Hz -> 413Hz.
Six quad opamps?  That would make one heck of an OverDrive
I remember you telling me you won a OD-1a pedal, was it broken?
The SD-1 opamp could also be upgraded to a JRC4558D or others, lots on evilbay
For the curious, heres a link to some really clear internal shots of the classic OD-1 through time
http://eu11.stripper.jp/pulcino/blog/archives/cat_boss_od1.html
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 01/25/2008 : 18:34:57
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Got the new SD-1 the other day, a 2000 model. It was fun to play around with two SD-1s at once, and good to know my '85 MIJ sounded as good too, despite the age.
The mod took about an hour and needed only two new comps. The rest get switched around. Even tho I could of done tons of mods on this, I wanted to start with the attempt at the classic OD-1 dual opamp sound.
It first when I turned it on, I was really impressed the sound (and the fact I didn't screw up the pedal)
Obviously there is less bass due to the rc corner, but this has a nice softened bottom end. Really visible overall next to a real SD1 regardless how much you twist the Tone knob. Going to keep it on my board for a bit and play with it some more.
Wondering about R14 on the SD-1, should it be jumpered too? |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 01/26/2008 : 02:59:47
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quote:
Originally posted by ChristoMephisto
Haven't had a chance to try it. Need another SD-1 before I try it.
Learned my lesson last time I modded my SD-1, and missed the original sound from it. Got one thats 22 years old now, and love it.
On the look out for a new one, good thing their plentiful, and way less in cost than an original OD-1.
About time too, why were every other mod for a TS or a Foolsclone, why not mod it a good classic
Was thinking about what to do with the tone knob. Came up with changing it to a high band pass before the clipping at R4. Wiring up a 82k resistor and the 20k pot in series. Crank the Tone knob, and its the OD-1 sound, back it off for a tad less bass 338Hz -> 413Hz.
Six quad opamps? That would make one heck of an OverDrive
I remember you telling me you won a OD-1a pedal, was it broken?
The SD-1 opamp could also be upgraded to a JRC4558D or others, lots on evilbay
For the curious, heres a link to some really clear internal shots of the classic OD-1 through time
http://eu11.stripper.jp/pulcino/blog/archives/cat_boss_od1.html
Hi Christo
About the OD-1, (sadly not an A version) it was fully functional,
8 PIN 4558.
I managed to get the data sheets (still at work) for a few different versions of the 3403 with some application notes, let me know if you're interested.
The SD-1 (OD-1) mod sounds interesting, put up some samples if you can manage?
Regards Dr. Bob |
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 03/02/2008 : 18:38:24
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Found a use for the tone knob on my converted SD1, which I've renamed ODrive by adding a cool ESD sticker that looks like an O.
I took a 1p6t rotary switch and gave it five different clipping options, and the last being a diode lift. Mounted them on a small perf board and stuffed them in the battery chamber.
Just finished and couldn't be happier.
In order its the Indyguitarist Chocolate clipping, The popular Fooltone clippers, OD1 style, TS style(w/47pf cap), two LEDs, then the lift.
Theres slight volume drop in the choco and TS compared to the others when you rotate the knob, and the diode lift is flabby with the drive cranked, pull it back and its much smoother.
http://i179.photobucket.com/albums/w283/ChristoMephisto/ODrive.jpg
http://i179.photobucket.com/albums/w283/ChristoMephisto/ODriveclippers.jpg
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 03/03/2008 : 08:40:34
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Hi Christo
We are all waiting to hear your conclusion?
But I realize you may some time with your new MULTI-SD-1
before you find a tone or tones that you like.
Regards Dr. Bob
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scrappy1
Bronze Member
USA
118 Posts |
Posted - 03/03/2008 : 16:45:45
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That's Brilliant!
"ChristoMephisto",
Do you plan on selling/ sharing your mod?
I have a couple spare SD-1's that I was wanting to mod, but I was running out of options so here they sit.
What a great idea you came up with! |
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DeFrag
Moderator
USA
3409 Posts |
Posted - 03/03/2008 : 20:43:19
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| Kewl! |
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 03/03/2008 : 21:21:27
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No problem, would love to share it since information on the net should be free. Its where I got my info from.
This is just an expansion of the Langraff mod where there is a diode lift, giving a clean booster. You could easily do it with a 6p DP3T on-off-on toggle, where center is the diode lift, and an option of clipping at either side.
For some reason I had three mini 6p rotary switches from smallbear that are the size of a regular toggle. Perfect I thought.
You will need a small perf board big enough to fit in the chamber, line the bottom with electrical tape after soldering to avoid shorts.
Pop out the on/off sw and shove the battery clip inside and away, it'll be in the way.
The small notch is where you will be running the wires.
Plan out your clipping diodes as you see fit. That could take a bit.
Solder them up in parallel like you see in the schematics. The D4 line running one way, and the D5/D6 the opposite.
Solder wires to each tab on the rotary, cover with heatshrink if you got it. These will go to each of the clipping options. Solder the diodes to the perf board with the D4 neg. towards the common line that will lead out of the perf to the real pcb at the top of D6 (did i mention to remove the original diodes first?) The roots or common tab on the switch go to the top of D4 (positive side).
The cool thing with this rotary is that line 5/6 have a different root, so hard clipping could be an option.
The original tone knob is too small to fit on the new rotary, so I may switch it around like on the DS1 and have the Level down in the middle
Let me now if that helps. The next switch I add will be a tone shift of OD1 sound(thin), Bassy, and Fat Bass. All with two caps and toggle. |
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scrappy1
Bronze Member
USA
118 Posts |
Posted - 03/08/2008 : 05:57:50
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That helps "ChristoMephisto", but.....
That is too confusing for my warped brain.
Would you be up to doing it for me?
For a price of course.
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 03/08/2008 : 06:41:41
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sure, pm me and we can work something out
i live up in Canada,eh |
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scrappy1
Bronze Member
USA
118 Posts |
Posted - 03/16/2008 : 20:10:08
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Hey "ChristoMephisto"
I have written a couple times but haven't heard back from you?
Please contact me if you want to do the mod for me.
Thanks. |
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scrappy1
Bronze Member
USA
118 Posts |
Posted - 03/19/2008 : 23:34:36
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Thanks ChristoMephisto!
Pedal is on the way to you!
Can't wait to get my MOD-1 "MephistO'Drive"! |
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 03/22/2008 : 12:53:13
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Found a way to get tube like fuzz from it
bwahahaha |
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scrappy1
Bronze Member
USA
118 Posts |
Posted - 04/11/2008 : 08:03:05
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Just wondering what else you have come up with for the MephistO'Driver?
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Topic |
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New SD-1 mod
