Multiple Ins and Outs

killsurfcity · Posted: Thu Apr 14, 2005 6:17 am Post subject: Multiple Ins and Outs

hey all, i noticed on the soundlab schematics for the patched out version, that there are multiple cv inputs and outputs to the same sections. for instance 3 cv ins to the osc. this makes sense for certain kinds of jacks, but i'm using stackable banana jacks. this seems like a dumb question, but just to be sure... do i really need all of those redundant connections if i'm using stackable jacks?
i need more realestate, so i figure if i eliminate those i can add other things, like a section of 1/4 to banana adapters for interfacing with other synths (like my friend's ms-20), or maybe an amp for an internal speaker, or the sample and hold, or all of the above. lol.

if this may not be such a good idea (i've never owned a synth, so i wouldn't know) let me know. i'm trying to make the most logical interface, but i don't have a lot of experience.

thanks,

-et-

mosc · Posted: Thu Apr 14, 2005 7:12 am Post subject:

Generally on any modular synth it is safe to stack outputs but not inputs. That's because you can not mix CVs or audio signals just by shorting two or three together. You need a mixing circuit of some sort. An output, on the other hand, can be taken to several inputs with the stacking plugs or multiples.

killsurfcity · Posted: Thu Apr 14, 2005 8:33 am Post subject:

elektro80 · Posted: Thu Apr 14, 2005 8:54 am Post subject:

killsurfcity · Posted: Thu Apr 14, 2005 9:55 am Post subject:

blue hell · Posted: Thu Apr 14, 2005 10:00 am Post subject:

For G2 see http://www.clavia.se , there is a software only demo version available for PC and Mac.

Jan.

mosc · Posted: Thu Apr 14, 2005 10:11 am Post subject:

elektro80 · Posted: Thu Apr 14, 2005 10:12 am Post subject:

It is the Clavia G2 ( the new nord modular ). It has a software demo which is in fact a virtual synth of sorts. I guess mosc and teh rest of the G2 guys have to explain this more in detail. The main point is however that it is theoretically possible to set up a model of the sound lab in that software... with resulting audio. If not completely 100% a sound lab synth, you will anyways be able to study the modules and routing possibilities. A learning tool?

killsurfcity · Posted: Thu Apr 14, 2005 10:26 am Post subject:

hahaha. i love the dancing bananas!

good. now i'm starting to get a handle on it. thanks.

in response to the g2 commentary:
i just may do that, for the hell of it. maybe patching around will give me ideas about what the placemetn of things should be logically. i'll let you guys know if i find time to give it a go.

-et-

paul · Joined: Feb 22, 2005 Posts: 31 Location: Italy

Very interesting topic!
I'm not really use to with patching and I'm fighting with myself (since long time) on how to finish my Sound Lab, if normalized, patched or both version all in one... I think I'll decide for normalized version but with multiple CVs ins.

The only thing is that I'm testing at the moment the multiple CVs option and I can note as follows:

a) with no CV ins the Sound Lab VCO sounds at a certain scale tuning.

b) connecting an external sequencer via 1/4" jack into the CV input, that scale tuning change immediately to a different scale.

c) connecting the S&H circuit to the same CV input the scale tuning change into another different scale tuning.

d) connecting the sequencer and the S&H at the same time by multiple CVs ins (through 100K resistors for each devices), the scale tuning is different again.

I think it is normal that different devices shot its own scale tuning.
So why the Sound Lab needs the scale adjustment procedure?

Sorry if my consideration and my question can result stupid but I need to learn a lot about Synths (I hope my english make sense too).

Thank you
ciao

killsurfcity · Posted: Fri Apr 15, 2005 5:13 am Post subject:

paul · Joined: Feb 22, 2005 Posts: 31 Location: Italy

thank you killsurfcity,
another little step is clear to me now!
So, I can immagine that the scale adjustment 1v/octave procedure is needed to play with a sequencer too ... or I'm wrong.
ciao

ps- read in english is more easy than speaking or writing .... thank you anyway!

killsurfcity · Posted: Fri Apr 15, 2005 8:06 am Post subject:

Afro88 · Posted: Fri Apr 15, 2005 5:38 pm Post subject:

Some sequencers are tuned to notes, some aren't. It depends what paul wants to use to sequence it. Like you say, I don't think the scale adjustment will be necessary if it's a pure cv sequencer with no notes.

paul · Joined: Feb 22, 2005 Posts: 31 Location: Italy

.... Sorry but i think scale adjustment procedure is always necessary if you want all the notes play real notes always.

Without that procedure, everytime you play for example "C0+C1+C2+C1+C0" (with keyboard or sequencer via CV), some of those notes will play as pure "C", some other will not.

Someone inform me, if i'm wrong.

Thank you
ciao

Mike Walters · Joined: Mar 24, 2005 Posts: 29 Location: Chapel Hill NC

It depends on whether or not each sequencer step is scaled or not (not variable)... But if each step is on a completely variable slider or pot, then it doesn't matter. What would matter is if you took the sequencer you have after it's scaled to the sound lab (for example, step one = C1, step two = E1, step three = G1, each tuned individually after it's plugged into the SoundLab's CV inputs), and plugged it into another 1v/oct synthesizer that's scaled properly, it would be out of whack. What would also matter is if you used a MIDI-to-CV sequencer.

But yes, if you use a keyboard, the scaling is a must.

paul · Joined: Feb 22, 2005 Posts: 31 Location: Italy

Thank you Mike.
I'll do the scale adjustment procedure.
I intend with (my next step) to build the Ray's Matrix Scanning 1v/oct Keyboard
ciao

Mike Walters · Joined: Mar 24, 2005 Posts: 29 Location: Chapel Hill NC

I should also point out that I did the trim-pot scale mod, and haven't had much success in getting it to scale properly with a 1v/oct controller. But I didn't use tempco resistors, and I think all the resistors I used were rated no less than 5% (but I didn't measure them), so that might be why. I also haven't really tried too hard to find the "sweet spot" on the oscillators that would be in tune.