Joined: Jan 18, 2007 Posts: 95 Location: Mark of the Dane
Audio files: 4
Posted: Wed Mar 28, 2007 12:40 pm Post subject:
Sonarbase wrote:
Have you tried lowering the voltage to 12 or 9v?
The 15 volts is from a modular synth PSU. Is it worth putting a 9 or 12 volt regutator between the 15v and 5v? (This is really a question of heat dissapation, aside from the volume issue the module works fine).
Joined: Mar 31, 2007 Posts: 2 Location: ruhrgebiet / germany
Posted: Sat Mar 31, 2007 11:23 am Post subject:
Hello to all,
for the first: CORON DS7 Drum Synce Clone is very smart thing and it sounds proper.
I am a "newbee" and to build the DS7 is my first project. I have some (perhaps banal) questions and i hope i will find help.
I build my personal DS7 after the stripboard version from Uncle Krunkus ( 19 Jun, 2006 1:46 pm, Thread).
01. To connect the "VCO input mod." i have to run wire from jack to leg 3 of CA3080 via 100K resistor and 100K pot. To which leg i have to run the wire with jack, resistor & pot, if i use LM13700?
02. How to wire an external CV IN?
The "CV mod" for DS8
includes 1 CV IN-jack;
the "CV mod" for DS7
includes 2 CV IN-jacks. Why?
03. What is the difference between a) Trigger Sens + Jack, b) VCO input mod + jack and c) Attn CV IN and CV IN 1&2 jacks ? What can i do with this three jack-INs & their knobs?
04. Look the stripboard version.
What´s the thing labled C20 on the top left? Is it perhaps C7 (1uF/16V) from the parts list?
1. Leg 3 on the CA3080 is the + input. On an LM13700 you have two, Leg 3 and Leg 14. One for each "clone" on the layout.
2. CV Mods are just ways of connecting extra CV inputs, and you can add 1, 2, 3 or maybe even more if you like. They all just have to go to the same spot, through a 100K resistor.
3. The trigger sens and it's jack look after an external trigger input. eg If you plugged one of the outputs of an analogue drum machine (ie TR707) into the trigger, the drum machine would trigger the DS7 whenever that drum was programmed.
The CVs are ways of controlling the pitch of the VCO. So you could play "tuned" toms using a CV keyboard, by plugging it into a CV in. Those toms could have a bit of vibrato on them if you plugged an LFO into another CV in. etc.
The VCO input mod is a way of adding another source to the mixing section, eg: noise.
4. C20 is a 10uF stabilising cap across the regulator. I put one for each clone. It's not on the schem I just looked up, but I know it was on the one I was working off for the layout.
BTW, I don't think that parts list matches up with the shem I used for the stripboard layout. _________________ What makes a space ours, is what we put there, and what we do there.
Joined: Mar 31, 2007 Posts: 2 Location: ruhrgebiet / germany
Posted: Sun Apr 01, 2007 4:05 am Post subject:
Thank You for answers. Now, i can begin. Once, the project is finished, i will post some pictures & sounds. But i have still a little question:
You wrote: "CV Mods are just ways of connecting extra CV inputs, and you can add 1, 2, 3 or maybe even more if you like. They all just have to go to the same spot, through a 100K resistor. "
But on the picture for DS7 i have to go to two spots through two 68K resistors. (Only on the picture for DS8 there are one spot and one resistor, but a 68K one.
Can You explain me this circumstances ?
Posted: Mon Apr 02, 2007 5:04 pm Post subject:
DS 8 squeal Subject description: File under general bleedthrough
Possible OT, but the DS8 rates at least an ugly cousin I guess, so here goes:
My DS8 unit built after mr. Bareilles schematics - and on his board design - keeps a rather piercing high tuned squeal going. This changes slightly when the balance/noise pot is twiddled, and gains pitch when closing in on the VCO only setting.
More bad news: the VCO pitch can be heard trough the pure noise setting, as can the LFO rate. Second, this all goes on without the envelope being engaged. The hum is ever-present - not too loud, just very, very annoying.
The DS8 schematics allready sported a 100uF across the power rails (before the 7805). I've used BC550's for all three transistors and made sure they are properly oriented.
The problem could be separated in two I guess - the envelope not "closing up" properly - there is (some) sound when there should be none - and second, the noise/VCO mixer (R33, R34 etc) doesn't allow a clean setting for either signal. Which means of course it could just as well be something completely different causing a blead-through.
After two days of troubleshooting, I thought I'd give the forum a try. So if it's not the wires, nor the transistors, nor some oddly oriented electrolyts, what could it be? I've used different 741's and NPN's with rather minimal effect.
It's not obvious (to me) which pots should be used for which positions. I know the 1M lin more than likely would be for the LFO, but the others I'm not sure about. How did you decide this?
There are no bypass caps on the the schem or the PCB, so I would definately add those. A 100nF on the solder side of the board, from the +ve pin to gnd and from the -ve pin to gnd (if applicable) on every chip. Get them as close as possible, with very short leads.
The mixing pot shunts the signal you don't want to GND, so bypass caps could make a big difference.
Of course checking that you've emulated the schem exactly goes without saying.
A small cap, say 10-50pF across R35 could stop the 741 from squealing if that's where the high pitched tone is coming from. I assume it's boosting the noise from the transistors by at least a gain of 10, and that's where op-amps start to whine from what I've learned. (and I still have a lot to learn, so don't hesitate to correct me Jan, or Scott, or anybody else who knows for sure. ) _________________ What makes a space ours, is what we put there, and what we do there.
I used only 47K and 1 megs, having had success with those on the DS7.
I will add bypass caps all over the place just after coffee - starting with that gnarly 741 - which probably is the main culprit in this. _________________ - autoprod
Bypass caps all in place, things didn't improve too much.
A 50pf cap along R35 could not remove the disturbances: Bigger ones did remove the squeal nicely, but also got rid of the noise altogether. At least I know the problem is around the 741. All bleedthrough from the rest of the circuit, with the balance pot at VCo only, is utterly gone now when the noise is turned off. Turned on, both extreme positions of the balance pot produces a mixed signal.
I'm considering a rebuild of the noise generator - if no one has another magic trick up their sleeves.
And what good does R36 do anyway? _________________ - autoprod
Joined: Mar 22, 2005 Posts: 363 Location: Boston
Audio files: 1
Posted: Fri Apr 13, 2007 6:25 am Post subject:
These ds7's are really great. I built 2 last year, one for myself and one for a friend. Both had wooden cases and sliders. [here's a pic]. Its really fun to play and very expressive. My friend attached a guitar strap to his. He just came back from a US tour with his band and said he had a blast with it.
I often trigger mine with a Roland TR-707 that has seperate outputs for each drum voice.
When I have time (ha!) I'd like to build a box that has 3 or 4 PCBs (maybe 2 would be ds8's). No onboard Piezos...I'd think it would be too hard to vibrationally isolate them. then I could use the 707 as the triggers. fun!
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_________________ Freq Out
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flickr Last edited by Photon on Thu Aug 30, 2007 4:34 pm; edited 2 times in total
Hey Dnny, how strong of a signal do you send into your vca in mod? I've got four DS-7's, ready to go in one box, and i wanted to be able to add in a noise source. I've tried a couple of things on breadboard, but the 100K pot always acts like a sort of volume control. If i lift the ground leg and leave it wired as a var. resistor, i get some noise in, but its very faint. I haven't gone over 15mV p-p, for fear of damaging my precious CA3080's. Any insight would be greatly appreciated.
-justin
Joined: Mar 12, 2005 Posts: 519 Location: Helsinki, Finland
Audio files: 8
Posted: Sun Apr 15, 2007 1:41 am Post subject:
I have used the Ray's Multi Noise and Random Gate/Trigger Generator as a source it gives quite beefy output +- 10V to 12V when powered whit +-12V, but i have powered it whit +-9V so mine gives +-7V to 9V, but my DS7 is not whit CA3080 but whit LM13700. The 100k pot is intended to be volume control for the incoming noise.
a good rule of thumb is that you don't exceed the supply voltage on any of the chips inputs, so if you are powering the chip whit +-9V you can input +-9V but not +-12V.
Alright thanks. According to the schem, the CA3080 is +5V. So I will have a go at beefing up the noise. Maybe just under 5V should do the trick.
-justin
Posted: Mon Apr 30, 2007 2:00 am Post subject:
Re: ds7 Subject description: breadboard
Sonarbase wrote:
scorpiistar wrote:
hi....im new....i just completed the DS7 on a breadboard, and am ready for testing! seems you can pull C2 3u3/sweep and it makes no audible difference ........i think tomorrow ill try the attack decay mod.....any requests?!
And? Did it the attack mod work out?
S.
sorry havent logged on in ages....i ended up building rene schmitz 555 based ADSR and the scope of sounds available pushed me down the path toward building an analog synth based on the ds7 VCO/VCA core.....its complete and working in a rudimentary form.....i dont have the drawings available yet, but will make them available at some point
also ppl might like to look at the LFO it feeds into the voltage bus that sets the frequency of the VCO i found that you get a better effect with the LFO modulating the VCA at pin 5 of the 3080......
Joined: Feb 07, 2007 Posts: 351 Location: Zagreb, Croatia
Audio files: 7
G2 patch files: 4
Posted: Sun Jun 03, 2007 7:03 am Post subject:
so with cv1 and cv2 and trigg. inputs i can hook ds7 to 16 step sequencer from MFOS? how would that sound? do anyone have this kind of setup to record a clip or two?
i plan on building a ds8 to accompany my ds7 - its just too much fun to have them.
now, i have the pcb layout and the components overlay for the ds8, but how do i connect the pots? i am not sure if copying the way they are hooked up to the ds7 is an ok thing to do...
does someone have a wiring diagram? marc b.s site does not have it (or i am too blind)
Posted: Thu Aug 30, 2007 4:18 pm Post subject:
missing pdf/images: How to wire an external CV IN?
does anybody still have the schematics/diagrams that are now missing due to the crash? i am about to build the DS7 and would love to have the missing charts:
02. How to wire an external CV IN?
The "CV mod" for DS8
includes 1 CV IN-jack;
the "CV mod" for DS7
Posted: Mon Sep 03, 2007 8:59 am Post subject:
Re: missing pdf/images: How to wire an external CV IN?
loss1234 wrote:
does anybody still have the schematics/diagrams that are now missing due to the crash? i am about to build the DS7 and would love to have the missing charts:
02. How to wire an external CV IN?
The "CV mod" for DS8
includes 1 CV IN-jack;
the "CV mod" for DS7
This one?
cheers,
Mike
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Here's my DS-7 drumset. Only two of four pads were installed, then I got sidetracked playing it for an hour. Instead of separate outputs, I used a version of a simplified 4->1 mixer from J.D. Sleep's site. The whole thing runs surprisingly well on a 9V battery I found while cleaning up! The bottom four holes in the case are for noise amt when I get one built. Then it will be supreme!!! And while it doesn't play quite as well as my friend's vintage Gretch kit, it didn't cost me nearly as much, probably under $100.(sorry the pics are blurry, I'll take some new ones and replace them...)
-justin
Very nice! One day I'll get around to my percussion concepts too. Good to see you're putting the effort into the mechanics as well as the electronics. Interfacing is an important part of creating something truly unique, IMHO. _________________ What makes a space ours, is what we put there, and what we do there.
Posted: Wed Sep 12, 2007 7:27 am Post subject:
ring modulator???
somebody mentioned a ring modulator that use the lm13700...but the link is dead..
anyone still have the schematic???
(and it holds three DS7´s on one 10cmx16cm board.
and if you build all three DS7´s. you need 2 LM13700 so the one half(of LM13700) unused can be used on Ring Modulator - See: Aaron Crams ringmodulator)
Posted: Sun Sep 16, 2007 6:05 pm Post subject:
Re: ring modulator???
loss1234 wrote:
somebody mentioned a ring modulator that use the lm13700...but the link is dead..
anyone still have the schematic???
(and it holds three DS7´s on one 10cmx16cm board.
and if you build all three DS7´s. you need 2 LM13700 so the one half(of LM13700) unused can be used on Ring Modulator - See: Aaron Crams ringmodulator)
wah, that sounds interesting indeed, let me know hows that working out for you (the samples man, the samples!).
man, going from vst designing to real electronics designing is so annoying, takes so much time to get the basics in before you can start doing neat things. but yeah, ill shutup now.
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