1/4" or Banana

[zipzap]

Old (and new) industrial stuff is often a great house for a synth!
Every time i see some factory or something from the inside, i see modular synths everywhere.

[MattofMattRabbit]

i built a delay pedal into this brass ashtray-thing that looks like a clock, i thought it was clever.

[dnny]

[blue hell]

[mosc]

[BobTheDog]

Hi Guys,

This is the original badger video.

http://www.weebls-stuff.com/toons/badgers/

Cheers

Andy

[toppobrillo]

i'm with mosc, sorry dnny, i actually thought you were telling a joke!

josh

[toppobrillo]

hey zipzap, so then you'd need logic that says "when i am plugged, whether 1 or 0, listen to me, not the bus" so, "floating" input is ignored.. tri-state logic. is this what you would want?

josh

[zipzap]

I don´t know anything about tristate logic. So i´m sorry i can´t tell you i don´t know what i want...
I posted a thread in an electronics forum, someone gave me this as an solution. It only works with signals that have a rather regular timing, like clock signals. The monoflop to the left has to be retriggerable and has to be set to hold longer than the frequency of the ext. in.
When the Ext. signal stops the /q of the monoflop will go high (eventually), allowing the internal signal to pass the and-gate.
The Gate to the right is an or-gate.
Pretty smart i guess, but with external gate for an adsr it´s not flexible enough. A pot could be used to set the timing of the Monoflop, eg if the ADSR were to be triggered by an LFO or sequencer, but then of course it´s much easier to have a swich. Maybe i really try to build one inside a little tube, roll ma own normalized jacks.
So what´s that tristate buissenes?

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[mosc]

Tri-state logic, see: http://www.labri.fr/perso/strandh/Teaching/AMP/Common/Strandh-Tutorial/tri-state-logic.html

I don't see how that applies here unless you are using the input strictly for gates.

If normalizing is very important, then use a phone jack - either 1/4" or 1/8".

This may be a way of detecting a connection on an input. Can someone simulate this. If there is no signal, then the voltage on the + node will be V- (negative power supply) which is lower than the voltage on the - node which is about 0.999V-. Thus the output will swing low.

Now, if you hook up a signal and the signal is higher than about .09V-, which is virtually always the case, then the output will swing high. Notice, you can't buffer the input on a circuit like this because there is a big difference between nothing connected and a signal at zero volts.

I haven't built or simulated this, so I may be off on a fantasy tangent. Anyone have any ideas why this may or may not work?

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[MattofMattRabbit]

if you really wanted a normalizing banana jack, couldn't you just design one that has a momentary normally closed pushbutton switch inside.

I suppose any solution for this problem isn't really cost effective when you could easily just go get some 1/4" jacks instead

[Macaba]

Mosc-

Your circuit doesn't simulate any outcome. Tough luck

Maybe you want something like this:

http://hyperphysics.phy-astr.gsu.edu/HBASE/electronic/schmitt.html

Mac.

[mosc]

Sure, a toggle switch or a conventional normalizing jack is the way to go if you want normalized connections. This concept of a normalized banana jack is interesting.

Macaba - a schmidt trigger is not what you want. You want a circuit that detects if something is plugged in vs. when something is not plugged in. If you simulate this by hooking up a voltage source to the input, then the output will stay at the rail. Run two simulations - one with nothing hooked to the input and one with a small voltage. Zero volts on the input is completely different than nothing.

[zipzap]

Well, i guess it isn´t all that important. A swich will of course do. on the other hand, since you guys got me convinced and i went to buy a bag full of Bananas yesterday i was really thinking about this. I mean it is nice if you just plug in and do nothing else. Makes the Panel more convenient also.
I want to use this for gates and clock mainly. So i´ll read through that tristate article and see if i can understand. In my synth i want to have a gate bus going to all envelopes, a clock bus going to sequencers, s&h and stuff.
But in other situations this is also useful. EG inserts for the feedback loop of an filter.
There is a economic matter to all of this. I don´t want to build a big circuit for one jack of an simple AR. As i mentioned, i´ll try to get some tube that can hold a 4mm plug, cut a peace just long enough so that the plug can press a swich at the end of the tube.
Or cut open one of the comercial small jacks that have plastic bottom, than attach the swich. Some handcraft for a change.
This might be the simpelest most reliable solution.
ps the 1/4" Jacks i had, the cheap ones, are not reliable. After some time the spring pushing the normalized contact dousn´t "spring" anymore...

[mosc]

I was at the Mercedes Benz repair place again today and the tech had the computer hooked up to a car. Here it is with all its banana splendor...

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[paul e.]

[dnny]

[zipzap]

[elektro80]

[mosc]

[MattofMattRabbit]

Well, I've decided to go with the banana jacks, haha. Although I did just win an ebay auction for 20 stereo switching 1/4" jacks, I guess I'll just save those for another project, or maybe the ins and outs of the minisynth.