Thomas Henry UD-1 Drum Voice Page Is Up

bblaze · Posted: Sat Jun 16, 2007 7:20 am Post subject:

hahahaha.. ya.. i spent the $60 for 3 boards.. the first one i botched and got halfway working.. didn't want to trouble shoot it much more.. the 2nd one works great.. gonna modify it a bit and test for buildin gthe 3rd one.. Smile

fonik · Posted: Sat Jun 16, 2007 2:00 pm Post subject:

that's realy great. wished i had the same luck with the super controller which i triple checked! . hooked the prototype up and NOTHING worked. i then discovered that the transistors were rotated by 180deg. turned them and still nothing works so i will have a jolly good time of troubleshooting next week...

Dan Lavin · Posted: Sat Jun 16, 2007 5:40 pm Post subject:

Fonik,

Just a suggestion, but you could use the folks on this forum to help check the layout. If 2 heads are better than one and the more the merrier, etc.....
Having stated this, I won't be able to assist as I head out on vacation for a week in the woods with 30+ Boy Scouts! But if you're still out of luck in a week, let me know. I've laid out many pcb's over the years and am willing to assist. Sometimes the mistakes are obvious to someone who hasn't spend hours staring at it already. Just a thought...

goldenechos · Posted: Sun Jun 17, 2007 7:58 am Post subject:

State Machine · Posted: Sun Jun 17, 2007 7:24 pm Post subject:

Thomas_Henry · Posted: Mon Aug 10, 2009 9:09 pm Post subject:

Hi gang,

Since things didn't work out this summer for getting six new projects out the door, I decided to catch up on my backlog of old things. Among them was my own hard copy of the UD-1. (My previous version had lived only on a breadboard).

Here's some pictures of it.

Thomas Henry

UD1 Front.jpg

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Front Side

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UD1 Back.jpg

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Back Side

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vtl5c3 · Posted: Wed Mar 31, 2010 11:17 am Post subject:

Quick question: can the 500K pots be substituted with 1M?

State Machine · Posted: Wed Mar 31, 2010 3:50 pm Post subject:

vtl5c3 · Posted: Sat Apr 10, 2010 12:58 pm Post subject:

Thank you. That's good to know, since I already have a bunch of 1M pots on hand.

Another question: I have a schematic for mods to the UD-1, including adding a volume decay pot, peak limit resistor and lower pitch cap. I cannot find the source for that. Can anyone point me to it? I'm guessing there's some notes that go with it, which I would like to review.

State Machine · Posted: Sat Apr 10, 2010 2:37 pm Post subject:

vtl5c3 · Posted: Sun Apr 11, 2010 7:57 am Post subject:

Hi Bill,

Here's the diagram I was referring to. I don't take any credit for it, nor can I vouch for its accuracy. It looks like your schematic from the UD1 PCB docs, with some extra stuff added to it.

Romeo

ud1_mods_schem.jpg

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Adam-V · Posted: Wed Jul 28, 2010 4:12 am Post subject:

Hi Guys,

Finally got around to assembling one of my UD-1s and it works a treat but when the decay and the sweep are turned up, the pitch is a little high for my liking. If I was to disconnect the ground side of R1 and connect it to -15V instead, would this have any adverse consequences? I'd like the Initial pot to be able to counteract the higher pitch caused by the above mentioned settings.

Cheers,
Adam-V

Adam-V · Posted: Sun Aug 01, 2010 6:23 pm Post subject:

bblaze · Posted: Thu Sep 20, 2012 6:53 am Post subject:

cracked my ud-1 open a few days ago for some tweaking.. Any chance you still have the PCB image around still? I can't access it here

bblaze · Posted: Tue Sep 25, 2012 6:40 am Post subject:

maybe i'll approach this a different way.. attached is a sample that i *think* sounds incorrect.. This is a triangle wave going thru.. The tail has a sort of metallic sound, almost like the square is bleeding.. The waves from the osc look fine, but i feel like this shouldn't have that high pitched staticy sort of tail.. IT seems to be coming in at either the VCA or the output stage, but i don't really have a meter.. Looking for any advice here.. THANKS!

2 Kick - Copy.wav

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2 Kick - Copy.wav

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diablojoy · Posted: Tue Feb 05, 2013 1:36 am Post subject:

So i finally got round to finishing my first UD-1
pitch seemed way too high for a tom sound
up around 5Khz for its lowest initial setting- weird
checked everything C8 value, initial voltage,
voltages to the LM566 all seemed fine
even swapped the LM566
ended up trying a few different values in parallel with C8
which lowered the pitch ok
now the original value of C8 is .022uf according to the BOM and schematic
I ended up with 1uf to get down to a reasonable floor tom sound
and not a bad high rack tom sound with the initial pot all the way clockwise
I certainly dont get as low a freq as Bblazes sample
It all seems to be working fine but really that is a massive difference in cap values to get it to there.
any idea's anyone ?
I have another 3 yet to complete , just need to finish panel wiring
so I guess we shall see if they work out similar.

elmegil · Posted: Tue Feb 05, 2013 7:35 am Post subject:

Could it be that there's a charging resistor error? I would think a 10k instead of a 100k, for example, would behave similarly....

diablojoy · Posted: Tue Feb 05, 2013 1:53 pm Post subject:

one of the first things i checked was the resistor values off pin 6
I even lifted one side and metered them directly.
I have a few tubes of LM566 i must go through and check them all as well
some are obviously pulls , some look possibly fake a few look NOS
i shall see if this highlights some variance
the one i have going is working nice with the odd C8 value , i will wire up a second and compare

AlasdairMoons · Joined: Dec 03, 2011 Posts: 105 Location: East-Belgium

I would be interrested to in some PCB layout for etching ..

Are they still around or does sMs still supply some boards??

prophei · Posted: Sun May 24, 2015 8:41 pm Post subject: any information left?

Hey Guys...

I just pulled my old SMS UD-1 board out, but no longer have any of the documentation. i have no idea how to wire all the IO. Do the original docs still exist?

Thanks!

prophei

elmegil · Posted: Sun May 24, 2015 9:48 pm Post subject:

Scott Stites' site moved to here:

http://birthofasynth.com/Thomas_Henry/Pages/UD-1.html

elmegil · Posted: Sun May 24, 2015 9:50 pm Post subject:

Also I have this lying around, hopefully Bill is OK with me reposting it at this point....

(let me know if you're not, and I can take it down)

UD-1_Tech_Guide.pdf

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UD-1_Tech_Guide.pdf

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Appliancide* · Posted: Sun Apr 26, 2020 6:24 am Post subject:

Does anyone still have PCBs for this? If not, I might have to try this on perfboard.