Mixing GATES and TRIGS

funkyfarm

What would be the simplest and best way to "mix" gate signals ?

not a stupid multi jacks ? (strap between multiple outputs...)

I consider only positive voltages and only one active signal (step outputs of a sequencer)

This would work ?

with all 47k ? and another tied to ground ?

gates.jpg

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Adam-V · Posted: Mon May 14, 2007 4:15 pm Post subject:

A diode "OR" gate is what you need here.

Have a look at the diagram on the top left hand side of this page. You just connect a diode for each of the gates you require to be mixed.

Cheers,
Adam-V

Scott Stites · Posted: Mon May 14, 2007 4:19 pm Post subject:

Diodes are actually a pretty good way of mixing gates and triggers - each signal goes to the anode of a diode, with all the cathodes connected together.

That's how I mixed signals in the Klee gate bus - I just tied the diodes to the input of a Schmitt trigger CMOS device to give everything a bit of snap - wouldn't necessarily be required in this application.

Cheers,
Scott

funkyfarm · Posted: Mon May 14, 2007 10:30 pm Post subject:

Okay !

And with diodes, what happen if accidentally two +10V p-p are present at the same time ?

Boum ?!

Adam-V · Posted: Tue May 15, 2007 2:20 am Post subject:

Diode logic circuits don't operate the same way a mixer or summing circuit does in that the input voltages are not actually summed together. A two input OR gate, for example, with a 10V signal at each input will still only put out 10V (actually it would be closer to 9.3V allowing for the 0.7V drop across the diodes).

So no boom if two 10V signals are applied to the inputs.

Cheers,
Adam-V

fonik · Posted: Tue May 15, 2007 6:04 am Post subject:

Scott Stites · Posted: Tue May 15, 2007 6:30 am Post subject:

Adam-V · Posted: Tue May 15, 2007 3:26 pm Post subject:

Adam-V · Posted: Wed May 16, 2007 3:13 am Post subject:

Another alternative is to use ideal diodes on the inputs like Ken Stone used on his analogue logic circuit

EDIT: or there is his Boolean Logic Circuit

Cheers,
Adam-V

fonik

Scott Stites · Posted: Wed May 16, 2007 8:43 am Post subject:

Yes, ideal diode (dunno why, I always call them "perfect" diodes Embarassed

). I use a modified version of Ken's Analogic for the peak/trough function in my mixer. IIRC, Ken once told me the original Serge Peak/Trough was originally created for mixing logic signals.

Cheers,
Scott

funkyfarm · Posted: Fri May 18, 2007 10:12 am Post subject:

funkyfarm · Posted: Mon May 21, 2007 2:46 pm Post subject:

Adam-V · Posted: Mon May 21, 2007 5:19 pm Post subject:

Sounds like you're sorted then.

FWIW, I built a passive OR gate last night and it works brilliantly. It functions as either dual 3 input gates or single 6 input gate depending on whether there is a plug present in the 1st output socket.

I'll post the circuit and a picture tonight if anybody is interested.

Cheers,
Adam-V

funkyfarm · Posted: Fri Jul 06, 2007 11:46 am Post subject:

Yep !

Everybody is interested in passive OR gate ! Very Happy

Adam-V · Posted: Mon Jul 09, 2007 7:43 pm Post subject:

Here you go...

TriggerMixerSchem.gif

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2x3 Input/1x6 Input Passive OR Gate (Trigger Mixer)

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funkyfarm · Posted: Mon Jul 09, 2007 8:44 pm Post subject:

doctorvague · Posted: Tue Jul 10, 2007 10:14 am Post subject:

Thanks Adam!
I'm going to build it just like yours.

Fernando · Joined: Dec 30, 2006 Posts: 207 Location: Barcelona, Spain

IIRC, the schematic for Serge's Peak&Through is/was on the net for ages...
(see the link some messages below, thanks RF)

Anyhow, as usual, Ken did it =:)

http://www.cgs.synth.net/modules/cgs54_xor.html

Funky40 · Posted: Thu Jul 12, 2007 7:41 am Post subject:

I built my first one without the R1 to Ground. It's without any powerconnection.
It seems to work fine

My second one with Bat48 diodes is not working.
On this Module the Jacks are connencted to ground.
Seems that i have to solder in the Resistor.

Is there any importance to have the Groundconnection and R1 ?

Adam-V · Posted: Thu Jul 12, 2007 3:49 pm Post subject:

R1 is a pull down resistor which ensures that, when no voltage is presented at any of the inputs, the output is held low. This avoids the possibility of a "floating" input whatever all inputs are low.

Cheers,
Adam-V

Adam-V · Posted: Fri Jul 13, 2007 1:32 am Post subject:

I finally found a few spare minutes at home to take a photo of my finished OR Gate / Trigger Mixer so here it is.

Trigger-Mixer-Photo.jpg

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And here's one I prepared earlier

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Funky40 · Posted: Fri Jul 13, 2007 3:47 am Post subject:

Ahh, you have the Resistor to Ground, but no Ground connection to the PSU............
I really don't understand this Things.
Good to see the Picture, thanks alot.

funkyfarm · Posted: Fri Jul 13, 2007 4:27 am Post subject:

RF · Posted: Fri Jul 13, 2007 6:42 am Post subject:

Passive is nice - but the Serge Peak and Trough really added some nice options to my synth. For the minimal effort involved it has to be one of the more "bang for the buck" modules I've added.

The schematic is available many places, including this one from Ken Stone's site.

http://www.cgs.synth.net/synth/serge/pic/schem_serge_r3.gif

It's awefully simple.... and makes up for lossy diodes with a couple transistors....

Bruce