DUSG Help!

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cygmu
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Post by cygmu » Sun Jun 26, 2016 2:23 am

Good luck.

The only other tricky point with the DUSG build is the seven jumpers you need to install on the board. I found them hard to spot, and in fact until I read a build thread on here somewhere I wasn't even aware that they were needed. Have you put them in?

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peachfuzzmcgee
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Post by peachfuzzmcgee » Sun Jun 26, 2016 6:39 pm

yesssss I got a high frequency triangle outta one, gonna test the second one tomorrow. seems like I just needed to flip the transistors and rework wasnt as hard as some say it was. ive been anything but gentle to this board. One question though, I'm not sure how to wire the pot for the VC amount. ground is on the wiper is another but they have on the diagram that I have to connect two more wires from the pcb, counter clockwise and clockwise or something like.

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cygmu
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Post by cygmu » Mon Jun 27, 2016 1:17 am

Connect the VC pot as follows:
counterclockwise end to FA
wiper to FB
clockwise end to ground.

Useful diagram:
http://www.loudestwarning.co.uk/portfolio/dusg/

And congrats on getting it working!

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peachfuzzmcgee
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Post by peachfuzzmcgee » Mon Jun 27, 2016 6:08 am

cygmu wrote:Connect the VC pot as follows:
counterclockwise end to FA
wiper to FB
clockwise end to ground.

Useful diagram:
http://www.loudestwarning.co.uk/portfolio/dusg/

And congrats on getting it working!
Oh and since you've been pretty helpful I wanted to ask one question.On my initial test I mistakenly killed the LED's what's some LED's that I can use with this circuit since I keep hearing that I need low current.

Everything at my local microcenter seems to be bright or very bright so I'm assuming high current which would be bad I guess.

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Post by cygmu » Mon Jun 27, 2016 6:53 am

Like you I have heard that the current draw of standard LEDs will give the module problems.

If your LEDs are very bright and you managed to fry them, it sounds like they are already low-current LEDs (low current to light them means that they get bright easily and then you can fry them with too much current.)

If that is the case then you need to change some resistor values. The 1k current-limiting resistor near the LED needs to increase to 4k7 or a bit more. That will stop the current from killing your LED. For a smooth light/dim effect,
you might also try increasing the base resistor on the driving transistor: the DUSG board has 47k marked on it, but the schematic shows 150k, and on Loudest Warning / Bad Producer's recommendation I tried a 2M2 resistor in there with very nice results. (This last step is not really good design, because the operation of the LED will depend on the particular behaviour of your transistor which can be highly variable from one to another, but it works great in my build!)

I discussed this a bit with Ken Stone and he did recommend using 150k there if using low current LEDs.

I used these in my build
http://www.mouser.co.uk/ProductDetail/L ... 52bQ%3d%3d

and Loudest Warning/ The Bad Producer recommended these:
https://www.rapidonline.com/truopto-5mm ... -15-551199

The thing to check is the forward current of your LEDs (called "If"). 20mA is standard, 2mA is low current.

Have fun!

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peachfuzzmcgee
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Post by peachfuzzmcgee » Mon Jun 27, 2016 7:23 am

cygmu wrote:Like you I have heard that the current draw of standard LEDs will give the module problems.

If your LEDs are very bright and you managed to fry them, it sounds like they are already low-current LEDs (low current to light them means that they get bright easily and then you can fry them with too much current.)

If that is the case then you need to change some resistor values. The 1k current-limiting resistor near the LED needs to increase to 4k7 or a bit more. That will stop the current from killing your LED. For a smooth light/dim effect,
you might also try increasing the base resistor on the driving transistor: the DUSG board has 47k marked on it, but the schematic shows 150k, and on Loudest Warning / Bad Producer's recommendation I tried a 2M2 resistor in there with very nice results. (This last step is not really good design, because the operation of the LED will depend on the particular behaviour of your transistor which can be highly variable from one to another, but it works great in my build!)

I discussed this a bit with Ken Stone and he did recommend using 150k there if using low current LEDs.

I used these in my build
http://www.mouser.co.uk/ProductDetail/L ... 52bQ%3d%3d

and Loudest Warning/ The Bad Producer recommended these:
https://www.rapidonline.com/truopto-5mm ... -15-551199

The thing to check is the forward current of your LEDs (called "If"). 20mA is standard, 2mA is low current.

Have fun!
Actually I fried them more because of handling error because when I was testing the module originally I mistakenly let the led's pins touch each other, spark and then dead.

Well at my local micro center they do sell LED's with the corresponding resistor, that might be my bet bet instead of waiting to get a batch delivered from mouser or something similar of sorts. Thanks for the help though I might try to do what you did. :hyper:

EDIT: last question how does one go about switching the way that the pots go because for fall and rise faster is CW and slower is CCW. I would like to change it to what I'm used to on usual ADSR. should I just move the cable from wiper to a different pin?

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Post by peachfuzzmcgee » Sat Jul 16, 2016 2:54 pm

So I finished my DUSG and everything seems to be working just fine. Although I have never had a dusg before and wanted to know. My switch for rise/fall/both don't audibly seem to change anything. Everything seems to read right or so I believe but what sort of behavior is expected for it I don't have an oscilloscope to see the difference.

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Post by GryphonP3 » Sat Jul 16, 2016 3:09 pm

peachfuzzmcgee wrote:So I finished my DUSG and everything seems to be working just fine. Although I have never had a dusg before and wanted to know. My switch for rise/fall/both don't audibly seem to change anything. Everything seems to read right or so I believe but what sort of behavior is expected for it I don't have an oscilloscope to see the difference.
These switches effect how external voltage patched to the CV In modulates the slopes. Rise = it modulates rise time only, fall = fall time only, etc. it's not going to do anything if you don't have a CV patched to the CV input.
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Post by peachfuzzmcgee » Sun Jul 17, 2016 8:18 am

GryphonP3 wrote:
peachfuzzmcgee wrote:So I finished my DUSG and everything seems to be working just fine. Although I have never had a dusg before and wanted to know. My switch for rise/fall/both don't audibly seem to change anything. Everything seems to read right or so I believe but what sort of behavior is expected for it I don't have an oscilloscope to see the difference.
These switches effect how external voltage patched to the CV In modulates the slopes. Rise = it modulates rise time only, fall = fall time only, etc. it's not going to do anything if you don't have a CV patched to the CV input.
Ahh I see thanks! I wasn't exactly sure of it's behavior but I tested it out and it works! Finished my DUSG build in MU format finally.

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Post by Siri » Sat Aug 06, 2016 4:25 pm

Hi all,

I just finished wiring my dusg and followed loudestwarning's diagram posted earlier.

On Ken's page I can read "Turn the RISE and FALL knobs fully CW." [...] "There should be a 5000 Hz triangle wave present which can be changed to a sawtooth wave of lower frequency by turning down either the RISE or FALL knob."

But I get a high ptiched sound when I turn them CCW, not CW... Is it normal behavior?

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Post by yan6 » Sat Aug 06, 2016 4:53 pm

Thats seems correct for the wiring diagram. Compare it to kens and you will see that the left and right connection of the pots are different. In Charlies left is +12v where in Kens its 0v. You can switch the left and right pot connection to chamge direction of their action.

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Post by Siri » Sat Aug 06, 2016 5:08 pm

Thanks Yan6!

I was reading R*S DUSG pdf and apparently on his pcbs he allows to change the orientation of the pots, which confirms some people like to wire it one way, some the other way.

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Post by cygmu » Sun Aug 07, 2016 2:50 am

I asked about pot direction briefly just the other day:
viewtopic.php?t=166131

For "commercially available modules", it seems the vintage Serge go faster as you turn clockwise, whereas the Make Noise Maths (essentially the same module with some twists) goes slower. The beauty of DIY is you get to choose. For me the choice is a source of endless needless worrying :)

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Post by yan6 » Sun Aug 07, 2016 7:44 am

I have one panel where the silkscreen is showing faster when ccw. All my other panels show faster as cw. I would follow the panel notation, this way as you system grows its easy to remember how it works by looking on the silkscreen.

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Post by NiteEagle » Sun Dec 25, 2016 1:50 pm

cygmu wrote:Good luck.

The only other tricky point with the DUSG build is the seven jumpers you need to install on the board. I found them hard to spot, and in fact until I read a build thread on here somewhere I wasn't even aware that they were needed. Have you put them in?
Thanks for verifying this. The parts are coming and I saw the jumpers spots on the PCB and scrutinized the built board photos closely and saw jumpers installed, but couldn't see all of them. Found all seven spots.

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Post by tojpeters » Mon Dec 26, 2016 3:16 pm

I have built many of these.
Standard brightness LEDs are what this board is designed for.
A high brightness LED can be used with a resistor change outlined on the CGS build page.
LED problems/interactions between the sections are caused by inadequate power supply and/or too small gauge wire carrying power to the PCB.
If yours does not work you have bad soldering/lifted pads,wrong value part somewhere, part(s) installed backwards,missing jumper,or incorrect trimmer setting.
I wire mine so the rise/fall times increase as you turn the knobs CW.
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Post by animalman » Tue Oct 10, 2017 2:55 am

Having trouble myself...
Is the trimmer value "100k" important? As I only had a 10k I used it seeing it is set up as a voltage divider.

I have 5.4v on the END OUT but still wont cycle connected to TRIG IN. :bang:

Hitting the trig in with a external bipolar GATE I only get the negative trig values after the 33k but get both possitive and negative before the 33k..

Any pointers would be welcome :despair:

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Post by cygmu » Tue Oct 10, 2017 4:38 am

animalman wrote:Having trouble myself...
Is the trimmer value "100k" important? As I only had a 10k I used it seeing it is set up as a voltage divider.

I have 5.4v on the END OUT but still wont cycle connected to TRIG IN. :bang:

Hitting the trig in with a external bipolar GATE I only get the negative trig values after the 33k but get both possitive and negative before the 33k..
After the 33k resistor you are pretty much at the input to the LM3900 so you won't see interesting positive voltages there anyway.

Is this a CGS114 board by the way? If so, one thing to check is that you have all the transistors oriented correctly. If you use 2N3904/6 then the D-shape has to be backwards with respect to the silkscreen. Ken's boards have the emitter of each transistor marked clearly, so make sure your emitters are in the right places.

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Post by animalman » Tue Oct 10, 2017 1:22 pm

I was brave/stupid enough to strip board :roll: half a DUSG, so there can be errors from my routing. Pretty sure my wiring is correct as it's kind of straight forward.

I use a 10k on the LED. I get it to light up while jumpering the 22nf

Re: the transistors, am I right that the orientation will be right if they have the emitters tied together?

I've "beeped" it for solder bridges and IC powering voltage is as supposed.

Ready to give up on this project :deadbanana:

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cygmu
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Post by cygmu » Tue Oct 10, 2017 1:43 pm

Ah, really DIY!!!

What happens at the output (DCO on Ken's schematic) if you apply a voltage to the input (C)?

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5% resistors

Post by groove » Wed Oct 11, 2017 7:24 am

I inherited one of these from someone who partly built several CGS boards and then gave up on them. I am about to wire the dusg but I am a bit unsure if the installed 5% carbon resistors will be okay. Do I need to pull them and replace with 1% metal film? If I have to replace them I would rather do it before I start wiring...

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Post by tojpeters » Wed Oct 11, 2017 7:59 am

The resistors will be fine

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Rise pot not working

Post by groove » Thu Oct 12, 2017 1:10 am

Thanks, indeed the 5% seem to be fine. So I wired one half of my DUSG tonight and it mostly works, except that for some reason the rise pot has no effect. I measured that the rise wiper is putting out expected voltage range, and after the 82k/2.2k voltage divider I'm getting the same voltage range into the base of the 2N5809 as I get on the fall side, so that seems to be working. I'm not sure I understand the 4 resistors in the core, or the stipulation to match them for Vbe (do I match all 4 to each other or the 2xPNPs and 2xNPNs to each other?), and whether there could be an issue here or if I should look elsewhere.

Happy for any suggestions. I'll keep plugging away in the morning.

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Post by Jonachi » Thu Oct 12, 2017 1:36 am

What happens if you flip the switch for fall/rise/both? Just asking because I have a problem on one of mine where the rise or fall pot stops working depending on the switch. Someone else in another DUSG thread way back when had the same problem but never solved it.

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Post by cygmu » Thu Oct 12, 2017 1:52 am

Not matching the transistors shouldn't stop it working but might make it more temperature sensitive than it has to be. I wouldn't worry about that for now. And yes, if you're doing it, you match the PNP pair for Vbe, and match the NPN pair.

Do the other controls (CV in, 1V/Oct) affect the rise time?

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