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toppobrillo
Joined: Dec 10, 2005 Posts: 766 Location: oakland, ca
G2 patch files: 1
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Posted: Fri May 05, 2006 12:29 am Post subject:
my minisystem design |
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heyyya ihaven't been on here much lately...
i have been busy starting planning, prototyping and designing circuits to build a small, very portable and extra-versatile, fully patchable system...
unlike the guy who was on here a few weeks ago selling circuit boards, [which, by the way, i have some i could sell too, they are R-Wilson boards i made a looong while ago and prolly won't use] who said that messing around with the G2 had compelled him to put his hardware conquest on hold, the G2 has actually inspired me to build a take-anywhere small but awesome system for use on the go!
i have very little time to get it together if i wanna be able to take it out to california with me this summer, in fact, it may be unrealistic to expect to finish in time!
the past few days, i have been working on a ribbon controller circuit. i started messing with the PAIA Dual CV one with the diagram on the website....first of all, i am now TOTALLY sold on the dual CV control, that is cool. But, unfortunately, this PAIA design overall isn't so great, in fact, it doesn't really work as shown. the CV is generated OK, but the gate circuit and sample and holds don't work well...
oh well, i have made lots of changes and am Very close now to a good working circuit, just a couple of things to work out. i am trying to keep the parts count very small, i may have to break down and compromise on this one though..
josh |
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bugbrand
Joined: Nov 27, 2005 Posts: 846 Location: Bristol, UK
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Posted: Fri May 05, 2006 1:21 am Post subject:
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Josh,
That sounds really exciting - yeah, wanted to look at that dual ribbon for a long time..
The idea of mighty portable synths is great (--are you going for synth sounds or power processing?) - and what will you use for the case? I always think the casing / layout has a great influence on what sounds you'll get out of a device (..really - how it inspires you etc..!..)
And, yes, G2 - I've realised I should have got one a while ago and now I must remedy the situation and buy one asap... No doubt the G2 is just about the most wondrous instrument, but DIY things feel very different and have their own wonder. _________________ http://www.bugbrand.co.uk
http://www.bugbrand.blogspot.com |
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toppobrillo
Joined: Dec 10, 2005 Posts: 766 Location: oakland, ca
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Posted: Fri May 05, 2006 11:44 pm Post subject:
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hey bb yeah, i agree the layout and interface of an instrument that is actually meant to be played with hands [until we can use our brains!] is very very important and can kill creativity if not done well. this is what i don't like about newer commercial synthesizers in general.
these new design engineers are starting to yeild with more hands-on control- it doesn't matter whether the sound generation and processing are digital or hyped as 'fully analog' or whatever- the average consumer of these expensive machines [there are some that are better than others] doesn't know and couldn't tell the difference anyways. it's all about the interface.
like i've said before, if the Ensoniq ESQ-1 had a knob and switch or jack or whatever for every thing it could do, it would still bring the 2,000$ or whatever it sold for originally today, instead of $200 or even less. i paid 175 for mine. but, who wants to cycle through pages of menus like that? it's meant to be programmed and patches stored. that suits the some just fine i guess. not for me!
......anyways..... for the case i will use good old 1/2" plywood. the plan is to build it as a 'suitcase' type of enclosure, with a removable top via latches. i have cut and mitred 2 pieces that measure 14" x 9 1/2" one for the base, one for the lid. the ribbon controller and joystick and associated controls will occupy about 3" of this depth, so that gives me 6" x 14" of panelspace, which should be good. i will either build the circuitry blocks into module type panels, or one piece, haven't decided yet.
it would be alot easier to service if i could pull circuits out one-at-a-time, but this makes me have to think in terms of what to group together in each 'module'. an inspiration for this design is the music easel, which is a portable system containing standard buchla sized modules.
here is a picture of the plywood and the patchpoints i am using- my patch cables will be simply pieces of wire. and here is a picture of them in their native environment, an old 300-in-1 kit from radioschack. notice that they are uninsulated, i will heatshrink them and hot-glue them in or just use thin hardboard panels not sure about that yet either.
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toppobrillo
Joined: Dec 10, 2005 Posts: 766 Location: oakland, ca
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Posted: Sat May 06, 2006 10:10 am Post subject:
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ok so heres the different circuits i am going to [try to] include in this:
here's to all the geniuses behind this work!
[hahah looking at it now i think i must be a little crazy- oh well aim high!]
the dual cv of ribbon control, which, by the way now is about 99% there. CV is drooping a bit after hold is initiated.
a joystick controller with manual gate button. pretty simple
2 simple vc EG/VCA combos with a 'hold' function [prolly with OTAs but i have been thinking about a digital design also. i have alot of digital ICs.]
can be used together to create complex envelopes.
1 vclfo/ s&h combo with controllable slew [from moog]
1 vclfo with quadrature saw, tri and sine outputs [done digitally]
an analog shift register [serge one]
a dual cv quantizer [from oberheim]
a sum/difference, minimum/maximum module with inverters [my own things and serge] a cool way to get a 'divergence' CV, which is "X + Y" compared to "X - Y". good waveshaping.
an analog multiplier/divider [based on 633, marc bareille[sp?]]
2 simple as hell vcos with npn array thermal loop compensation [a-la moog]
a steiner style vcf
1 vc mixer [with a good old quad vca, thanks analog devices! 'interpolating scanner' idea- j haible] i have experimented with this in the G2 demo, its great! like the barberpole idea, only 4 stripes.
1 simple mixer
a noise/complex tonesource. havent put alot of thought into this one. maybe with it's very own BP filter.
logic gates/analog comparators
well yeah. that is a whole lot to cram onto a 7 x 14 panel. it may have to get a litlle bigger.
josh |
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mosc
Site Admin
Joined: Jan 31, 2003 Posts: 18197 Location: Durham, NC
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Posted: Sat May 06, 2006 10:14 am Post subject:
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Sounds like a great project, Topp. Those springthings are an interesting idea. Keeps the cost down - easy to get more patch cords in a pinch - no need for multiples.
Please keep us informed at this project progresses... _________________ --Howard
my music and other stuff |
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toppobrillo
Joined: Dec 10, 2005 Posts: 766 Location: oakland, ca
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Posted: Sat May 06, 2006 10:24 am Post subject:
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yeah the [potential] cost is like the one thing that i can't bear! so the plan is to use up all my surplus electronics and supplies, salvage what i can from where i can and work with what i got. i don't really want to have to order anything but perhaps some resistors and a few pots. i gotta be resourceful!
josh |
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toppobrillo
Joined: Dec 10, 2005 Posts: 766 Location: oakland, ca
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dnny
Joined: Mar 12, 2005 Posts: 519 Location: Helsinki, Finland
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toppobrillo
Joined: Dec 10, 2005 Posts: 766 Location: oakland, ca
G2 patch files: 1
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Posted: Wed May 17, 2006 6:10 pm Post subject:
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thanks. yeah the industrial sharpie doesn't hold up so well actually. i guess maybe if you give it like 3 coats maybe. |
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toppobrillo
Joined: Dec 10, 2005 Posts: 766 Location: oakland, ca
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Posted: Wed May 17, 2006 9:46 pm Post subject:
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just cause i myself really enjoy construction photos here you go. and congrats! on your moderatorship, dnny.
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dnny
Joined: Mar 12, 2005 Posts: 519 Location: Helsinki, Finland
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Posted: Wed May 17, 2006 10:40 pm Post subject:
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topp wrote: | .... and congrats! on your moderatorship, dnny. |
thanks id like to keep low profile about this but it's true - I'm now moderating the links section whit seraph.
and the circuit bending + soundlab -sections whit v-un-v.
but now that i start thinking i should announce this - so if anybody have problems they can turn to me.
daniel _________________ Association of experimental electronics
www.koelse.org
flickr: cable porn group |
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toppobrillo
Joined: Dec 10, 2005 Posts: 766 Location: oakland, ca
G2 patch files: 1
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Posted: Sun May 21, 2006 10:30 pm Post subject:
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so yeah i gave up on trying a more complex pcb with the 'dry-transfers' a real pain in the neck.. nstead, out of desperation, i decided to give that old beast laserjet a look. turns out it's a coupla broken gear teeth in the fuser assembly. poo. well i managed to fit a washer in there so the good gear gets a little bit of a grip on the broken one [this won't hold up too long i don't imagine, gotta use 'er sparingly] so i am now able to use my press'n'peel again. i got a good sheet and a half left, so i am good to finish out the pcbs for this project, i think. |
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toppobrillo
Joined: Dec 10, 2005 Posts: 766 Location: oakland, ca
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toppobrillo
Joined: Dec 10, 2005 Posts: 766 Location: oakland, ca
G2 patch files: 1
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Posted: Mon May 22, 2006 8:45 pm Post subject:
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i get so sidetracked... now i am going to finish that danged ribbon controller [see paia's dual CV ribbon].
i don't know if i have totally missed something about the original schematic, but it really won't work as shown. when the output of the op-amps go too negative, which i don't see how they wouldn't in the circuit shown, [see the 10M to V- in the 'trigger proc.' and note that the V tapped from the top-end of the ribbon is presented finally as negative] they pull the charge right out of your hold caps, through the "open" cmos switch. so i added a diode to the 'wiper' of the ribbon, which holds the 'V lo' only slightly [as opposed to very] neg. with no input, and a rectifier circuit to the amp that feeds V HI hold, so that it's output can't go negative.. which makes the s&h work well.
you could just add diodes in series with the V lo and V hi, with resistors to ground [before the cmos] to provide a discharge path for the caps.. this is basically an ASR generator, as the 100k into the hold amps sets the ATT time, the resistor to ground sets the DEC time, and your V in is your sustain level.
still i can't use as small a capacitor as i want to make transients faster in the output.. you can, but the way your finger presses the tactile pot, your V out will droop.. as you pull your finger away, you make contact with a smaller area of pot.. all in the technique i suppose.
the smallest cap im happy with is like .047 uF. i tried polystyrene, and it doesn't seem to do any better here than mylar here as far as i've seen...
anyways
josh |
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toppobrillo
Joined: Dec 10, 2005 Posts: 766 Location: oakland, ca
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
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Posted: Tue May 23, 2006 5:54 pm Post subject:
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topp wrote: | [what is the plural of axis?] |
ax·is
n. pl. ax·es
Source : http://www.thefreedictionary.com
Nice little joystick ! _________________ Jan
also .. could someone please turn down the thermostat a bit.
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elektro80
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Joined: Mar 25, 2003 Posts: 21959 Location: Norway
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Posted: Tue May 23, 2006 5:56 pm Post subject:
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"Careful with that Axis, Eugene" _________________ A Charity Pantomime in aid of Paranoid Schizophrenics descended into chaos yesterday when someone shouted, "He's behind you!"
MySpace
SoundCloud
Flickr |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
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Posted: Tue May 23, 2006 6:00 pm Post subject:
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elektro80 wrote: | "Careful with that Axis, Eugene" 8) |
English is just like a "sausage full of secrets" I guess ... _________________ Jan
also .. could someone please turn down the thermostat a bit.
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toppobrillo
Joined: Dec 10, 2005 Posts: 766 Location: oakland, ca
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Posted: Tue May 23, 2006 6:18 pm Post subject:
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heheh, "sausage.." that's great! |
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zipzap
Joined: Nov 22, 2005 Posts: 559 Location: germany
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Posted: Thu May 25, 2006 8:44 am Post subject:
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like the idea of a synth to go. Nice list of modules. I guess it is going to get bigger than first planed....? Why not build two small suitcases? You got 2 hands.
Quote: | a sum/difference, minimum/maximum module with inverters [my own things and serge] a cool way to get a 'divergence' CV, which is "X + Y" compared to "X - Y". good waveshaping.
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Sounds intersting. I can´t imagine what this is doing though. You described it well, but is there a more musically speaking description? What does it sound like?
And then there´s the shift register- is that the same as a sequencer? |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
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Posted: Thu May 25, 2006 9:04 am Post subject:
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zipzap wrote: |
Sounds intersting. I can´t imagine what this is doing though. |
You could try it with the G2 demo, it has the min/max module (its in the Level section). _________________ Jan
also .. could someone please turn down the thermostat a bit.
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zipzap
Joined: Nov 22, 2005 Posts: 559 Location: germany
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Posted: Thu May 25, 2006 11:14 am Post subject:
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I dit. Sounds cool, i´ve got no idea whats going on, but it sounds cool!
I connected two lfos to the minmax thing and that to a vco.
How is that done in real life? and how can i compare x+y and x-y? (in the g2 and in life)
Hope this doesn´t get to much ot... i´m just curious |
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ian-s
Joined: Apr 01, 2004 Posts: 2669 Location: Auckland, New Zealand
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Posted: Thu May 25, 2006 3:03 pm Post subject:
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zipzap wrote: | and how can i compare x+y and x-y? (in the g2 and in life)
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Then the 2 input mixer with the inverting buttons would do, but that is not so very interesting by itself. For example, subtract a copy of the input signal from the output of a LP filter and you get a HP filter. |
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zipzap
Joined: Nov 22, 2005 Posts: 559 Location: germany
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Posted: Thu May 25, 2006 11:59 pm Post subject:
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Thats great! Now i know what i need to build! so subtracting simply means mixing one signal with another one´s inversion.
Makes me thinking: Someone designed this cool moogtype vcf with bandpass out wich is 1 pole - 4 pole of the filter. Like that you could get hipass too, have a multimode moog cascade. If you have res turned up i think it won´t matterm you´ll keep the res that way, but i´m not sure about that right now. I´ll try to simulat that. |
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mosc
Site Admin
Joined: Jan 31, 2003 Posts: 18197 Location: Durham, NC
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Posted: Fri May 26, 2006 5:50 am Post subject:
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g2ian wrote: | For example, subtract a copy of the input signal from the output of a LP filter and you get a HP filter. |
So, just for completeness...
If you put a high pass and low pass filter in series, you get a band pass filter.
If you subtact the input signal from the output of a band pass, do you get a band reject or notch filter? _________________ --Howard
my music and other stuff |
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