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creatorlars
Joined: Nov 26, 2007 Posts: 524 Location: Denton, TX
Audio files: 4
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Posted: Fri Feb 01, 2008 10:38 am Post subject:
Anyone built Jorg's 909 kick PCB? Subject description: I'm having some trouble, my brain hurts... |
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I'm trying to build the 909 kick module detailed here:
http://www.analog-synth.de/synths/tr909/tr909.htm
I etched a board last week, but realized it was mirrored -- I tried to assemble it anyway, but when it was all put together, not working, and troubleshot to death, I ended up just reordering parts and etching a clean, new board.
I got this second board assembled and wired last night -- it didn't fire at first, but after putting in Thomas Henry's Trigger Conditioner between in the input jack and the Trig In of the board, I was getting it to successfully trigger the module from my Midibox SEQ3's gate outputs.
Pitch, Tune Depth, Compression, Distortion, Velocity, Decay and Output Level all seem to be having the effect they're supposed to, but I'm getting nothing out of the Noise Level, Attack, or Tune Decay controls. I can hear the envelope-controlled VCO and that sounds right (aside from tune decay and noise not working)... but it's accompanied by a very high-pitched pulse sound.
I've noticed some indiscrepencies between the drawn schematic and the PCB pdf at the URL above, and I've compared them to the 9090 schematics... I'm stumped for the moment, but I was just wondering if anyone else had built this before, or noticed any similar problems with the circuit.
Thanks!
Lars |
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creatorlars
Joined: Nov 26, 2007 Posts: 524 Location: Denton, TX
Audio files: 4
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Posted: Fri Feb 01, 2008 12:52 pm Post subject:
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Yes! A lead... I was comparing the 9090 bass drum schematic to Jorg's layout and discovered that the 330n and 470n capacitors are supposed to be polarized, which isn't marked correctly on Jorg's layout... and without a parts list, I missed it. I just picked up some .33uf tantalums and .47 electrolytics from the store... tonight I'll replace them and see if this solves my problem. I'll post my results.
If this works, I will replace the caps in my original board too -- it's still fully stuffed. If I get it working, does anyone wanna swap a working 909 kick board for somethin' cool? |
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ickystay
Joined: Nov 15, 2006 Posts: 142 Location: Oregon
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Posted: Fri Feb 01, 2008 3:08 pm Post subject:
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Sorry to say, Roland probably just used tants to save space. |
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6079smith
Joined: Jan 18, 2007 Posts: 95 Location: Mark of the Dane
Audio files: 4
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Posted: Fri Feb 01, 2008 3:22 pm Post subject:
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creatorlars wrote: | I etched a board last week, but realized it was mirrored |
Know the feeling.
I made this about 100 years ago, and I remember having the same problems, although I could get it to trigger okay... I recall some issue with the PCB, but for the life of me can't remember what it was. It sounds like you've come further than I did in that respect, because I couldn't get any sound out of it before I fixed it. Maybe I just made an etching error. Anyhow, in the end I stripped it down to four panel controls (Pitch, Tune Depth, Decay and Distortion) and was quite satisfied with the results. It's still in a box waiting for a front panel. I'll try and dig it out over the weekend and see if there's anything I can find that might help... but I do remember just using any old capacitors I had to hand, so I'm not sure that's the problem. Good luck with it. |
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bubblechamber
Joined: Nov 04, 2006 Posts: 279 Location: NYC
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Posted: Fri Feb 01, 2008 4:41 pm Post subject:
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I had those same problems and haven't had the will or the time to try again. glad I'm not alone in this.
david |
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ickystay
Joined: Nov 15, 2006 Posts: 142 Location: Oregon
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Posted: Fri Feb 01, 2008 5:24 pm Post subject:
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I have not compared the whole drawn circuit to the pcb.
I do see a 10K on the schematic shown as 100K on the parts placement. It's the one going from pin 6 of the far right TL072 through a 10uf cap to ground.
Also, pin 8 of that same ic should go through a 12K resistor before hitting the junction of the 4K7/0.47.
He did add a 1K between the pulse and attack circuit that is not in his schematic.
Edit: A couple other things. The transistor in the attack circuit (pcb) has a 150K resistor from base to ground- in the schematic it goes emitter to ground. Of course you see he has the out level circuit different.
Damn, now my brain hurts too! |
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creatorlars
Joined: Nov 26, 2007 Posts: 524 Location: Denton, TX
Audio files: 4
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Posted: Fri Feb 01, 2008 9:06 pm Post subject:
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Thanks for the replies.
I've been over this board a hundred times over the past couple nights... and, at least, I'm starting to understand the circuit a lot better! Hah. There's definitely some major problems with the noise circuit... ACTUALLY, I think I've narrowed it down to the "noise filter" section. I seemed to be getting some noise from the board's noise section eventually... but no noise was coming out of the "filter" section to sum with the pulse sound (I checked the sound at the pulse/attack output and it sounds right...)
I pulled out my 808 snare to see if I could get that noise generator coming through... and sure enough, doesn't pass the noise filter section, but if i patch it in right at the summing point w/the pulse section output on the attack pot, I can hear it correctly (naturally, it sounds horrible.)
The polarized capacitors didn't change much, but I can definitely notice better response with the Tuning Decay control. All the controls seem to be working correctly now (of course, noise level isn't doing anything due to the mentioned filter problem.) I can definitely hear the effect of the compression knob a lot better with some noise in the circuit.
So, I'm going to really hone in and check for any indescrepencies in the "noise filter" section against the original 909 schematics.
The other issue I'm having is out of the VCO (envelope 1) section... I hear a high-pitched "ding" on top of the correct sound. I'm guessing this has something to do with the pulse output going into the circuit incorrectly.
I found schematics for the original 909 noise source and it is vastly different from the one on this board. Also, if I patch in to the noise source output on this board, I hear the trigger signal too?? Maybe this is a similar issue to what I'm experience with the high pitched ding... some sort of bleedthrough. What would I do to fix something like that? a Resistor somewhere?
'
Anyway, if I can get the noise filter working right (and possibly a new noise source built, if the internal one doesn't start working)... and that "ding" sound eliminated... I'm going to be in business!! |
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ericcoleridge
Joined: Jan 16, 2007 Posts: 889 Location: NYC
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Posted: Fri Feb 01, 2008 9:35 pm Post subject:
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Please keep us updated; I'm populating this board this week also, wasn't expecting so many kludges! |
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creatorlars
Joined: Nov 26, 2007 Posts: 524 Location: Denton, TX
Audio files: 4
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Posted: Sat Feb 02, 2008 7:06 pm Post subject:
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Well after several more hours I'm calling this module "done" for now.
It's very useable... but, it's not the 909 kick. Still something weird going on that's preventing that really thick "CLUNK" kind of sound, so maybe it's something in the pulse circuit... however, all the controls now have /some/ sort of effect, and it still can produce a really punchy compressed kick drum sound with a good midrange register (which is what I wanted -- give me a punchy kick and a boomy kick and that's all i need.)
I may pull it back out and try to get it working 100%, but at this point it seems like less hassle to just make my own layout or just build it on protoboard, based on the 9090 schematics... and, I really don't have time for that, and I've already rebuilt it once. I'll keep up with the rest of you who are building it, to see if you can catch something that I didn't.
I was able to isolate and remove the "ding" sound by changing the resistance between the positive input/output pins of the op-amp next to the Tune Depth control. There was a 100K resistor there... putting a 50K resistor in series with it seemed to fix the problem. Something, somewhere, is out of balance. It's probably one or more very obvious component values being wrong. I fixed the suggested ones but it didn't help my problem...
I ended up just wiring the output of the noise circuit directly to the input lug of the Attack knob. This isn't accurate, but it helps by reducing the pulse from a "pop" to more of a natural attack sound.
I'll post some sound samples when I get the chance. Best of luck with this one. |
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ericcoleridge
Joined: Jan 16, 2007 Posts: 889 Location: NYC
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Posted: Mon Feb 04, 2008 9:49 am Post subject:
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creatorlars wrote: | Well after several more hours I'm calling this module "done" for now.
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Just curious; are you able to get sounds close to those samples on the webpage? Those samples were pretty right on, for me. |
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creatorlars
Joined: Nov 26, 2007 Posts: 524 Location: Denton, TX
Audio files: 4
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Posted: Mon Feb 04, 2008 10:13 am Post subject:
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it's 90% there. i can post some samples. tune depth, pitch, tune decay, compression, distortion, and everything all work as expected... but noise level is still a little weird.
i'm still confused on whether or not it's a problem with the VCO section or the Pulse/Noise section (they are summed together right before the output.)
I can only get a "click/pop" at the attack instead of a thicker "thud/clunk". It would seem like this is a pulse/noise section problem, but the little high-pitched "ding" was found in the VCO section... and the circuit was correct at the point of issue, i just hacked it by adding a resistor -- so something else, somewhere... is incorrect or unbalanced.
And, it could just be something weird with the noise section too. Like I said, I had to bypass the "noise filter" section (the resisters/caps between the noise output and the input of the Attack control.) So maybe I could look there again. Might be worthwhile to build an accurate 909 noise source clone to test it with, too... the one on this board is something different.
One thing that concerns me... when I hook a jack up to ground, power, everything on the board... i can still hear the trigger pulse very faintly. Which would lead me to believe that there is some sort of signal bleedthrough, and that could very easily be causing my problem.
In any case, it still sounds great. Running through a second compresser would probably add more thud to it. In my case, I'm writing percussion for loud distorted guitar/bass postpunk kind of setup, so I /have/ to have that really punchy kick to get through the mix. And this gets me there. The VCO range is huge, too... from extremely low to to extremely high. I might actually try to add an on/off switch to bypass the pulse/noise section, because it would make a pretty intense thick synthbass tone with just the VCA section.
Totally useful, even with the small issues, but if you build it --- lets compare notes and try to get it up 100% |
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bassmosphere
Joined: Sep 19, 2008 Posts: 17 Location: The Moon
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Posted: Sun Sep 21, 2008 8:08 am Post subject:
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Did anyone ever post a revised layout of this PCB with corrections? |
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rlorentz
Joined: Aug 13, 2008 Posts: 16 Location: Washington, DC
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Posted: Sun Sep 21, 2008 9:57 am Post subject:
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I tried to build this a while ago (1 year +) and learned an incredible amount of lessons.
I was building it on a big perfboard (3 inch x 6 inch or so) just going from schematics -> my brain -> soldering in part by part. This method works for me in general, but had never tried something of quite this complexity
Anyway, it was a gigantic failure. I started it knowing little of how the 909 kick worked (or any drum synthesis). By the end I at least understood what all the sections *should* be doing, and did have *some* of it working. I think my oscillators had noise issues in some places (so would quit oscillating), and for some reason my noise generator just would not work except rarely. Grounding techniques? What are those? Frustrating...
Funny, I gave up on it, and now just use that PCB as a bipolar 15V supply for my other bench adventures. That part turned out pretty clean and strong (although it could have been part of the issue, so if I have demons later I'll have to keep that in mind..)
Glad (and actually surprised) that I'm not alone on this. I was a bit irritated at the end of it all and wanted to build a 9090, but I hate that it's not in a desktop enclosure... _________________ Axios Records |
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211
Joined: Jul 18, 2006 Posts: 50 Location: Marseille - France
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Posted: Sun Sep 21, 2008 11:36 am Post subject:
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Here is another 909 bd clone,
http://www.bionicdimension.de/_drummachine-909-bassdrum.html
there is 2 differents pcb, one who can be trigged by author's midi interface (same triggering circuit than the original 909), and the other who can act as a stand alone unit (using cd40106).
Hope this help you to debug jorg's module ! |
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stinkebeest
Joined: Aug 24, 2009 Posts: 15 Location: Netherlands
Audio files: 1
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Posted: Tue Sep 29, 2009 2:26 am Post subject:
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I finished up wiring this a couple of days ago, and got quite dissapointed
when testing. all I got was hum/noise/berserker crackle...
as it turns out, pulling the unused 40106 inputs high took care of that. on to the next problem. I think somethings wrong around the Vca/envelop sections.
because,well... there isnt's really any eveloped vca action going on... at all.
I now get a continous note, which is pretty fat sounding, but not really what we're after here.
also, about the noise, i am getting some, but really soft, so i think changing that *-marked resistor could do the trick.
anyone had similar problems ? solutions ?
cheers,
Rudi |
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creatorlars
Joined: Nov 26, 2007 Posts: 524 Location: Denton, TX
Audio files: 4
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Posted: Tue Sep 29, 2009 7:45 am Post subject:
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I gave up on this one a while back, but ended up getting it to work as far as all the controls responding and the envelopes/vcas working for the click and shell sounds, but I think the source of my problems were in the noise circuit so it never quite sounded like a 909 kick. I'm going to build that other 909 board soon.
I'd check transistor values/orientations in the VCA parts of the circuit...
Good luck! |
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reve
Joined: Feb 23, 2008 Posts: 149 Location: USA
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Posted: Tue Sep 29, 2009 7:56 pm Post subject:
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Lars,
When you say "the other one," are you referring to the bionicdimension layout posted by 211 above?
Curiously (and eager for build updates), |
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creatorlars
Joined: Nov 26, 2007 Posts: 524 Location: Denton, TX
Audio files: 4
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stinkebeest
Joined: Aug 24, 2009 Posts: 15 Location: Netherlands
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Posted: Tue Nov 17, 2009 11:10 am Post subject:
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allright, after letting this thing rest for a while, i had another go at it, and i
actually made some progress.
the constant sounding tone issue i had is now resolved. I thought the
549/559 transistors could be substituted with 548/558. apperently, this
is not the case, and after replacing them, the issue was resolved.
it was now being silent, like it should be... BUT... it also didn't trigger. now, the trigger circuit on this thing is a cd40106, powered with +15 and ground.
now, don't those ic's change the output to high once the input voltage has passed the trheshold of 2/3 of the power sup ? so this would mean it needs a
trigger signal of 10v minimum, right ?
my sequencer puts out 5v triggers, so that's probably the problem. also, hooking up a wire to the sup rail and slapping the trigger input like an idiot,actually DOES trigger the device, and it sounds pretty much like i suppose it should.
once i fixed a way around this trigger problem, i'll check some more,and record some samples. does anyone have any ideas ? i was thinking about a comparator, could this work ?
cheers,
Rudi |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Wed Nov 18, 2009 12:09 am Post subject:
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stinkebeest wrote: | once i fixed a way around this trigger problem, i'll check some more,and record some samples. does anyone have any ideas ? i was thinking about a comparator, could this work ? |
it would not even work, it would enhance the possibilities. with a comparator in front you could trigger it with any signal. _________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source |
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creatorlars
Joined: Nov 26, 2007 Posts: 524 Location: Denton, TX
Audio files: 4
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Posted: Wed Nov 18, 2009 8:58 am Post subject:
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I think Fonik means to say that "it would work". You might look at LM311 comparator.
There is also a great Drum Trigger Conditioner circuit in Thomas Henry's Electronic Drum Cookbook, which you can purchase in PDF form I think. I used this as an input circuit to all of my 808 drum clone modules. |
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furio
Joined: Dec 25, 2009 Posts: 106 Location: Austria
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Posted: Fri Dec 25, 2009 5:25 pm Post subject:
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I am very frustrated with this project...I stopped trying since one month ago to get this functioning!! The greatest problem I find is that the sounds are very high. As far as I could remember it should be no problem to trig when the inputs Trig&Accent together connected is!! |
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PickNick
Joined: Oct 16, 2009 Posts: 82 Location: BP
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furio
Joined: Dec 25, 2009 Posts: 106 Location: Austria
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furio
Joined: Dec 25, 2009 Posts: 106 Location: Austria
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Posted: Tue Dec 27, 2011 1:24 pm Post subject:
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My Jörg's TR-909 Bass Drum rocks!!! I've substituted only the 6n8 in the middle with a 68n cap, but more resistor's and caps were found to have the wrong values... Interested? should I make a pic and post it? |
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