The Polyphonic Jack Choice?

phdinfunk · Joined: Jun 04, 2008 Posts: 119 Location: Taiwan

So initially I thought four voices for sure...

Use four prong XLR jacks.

Then I thought, three might be easier to manage, and could use normal XLR jacks...

Then it occurred to me?

What about Stereo 1/4" Jacks?

The only drawback I can see is the cable would not be shielded in reality (and I'd probably need to solder three wire cables to the plugs for best performance)... But I still wouldn't have any annoying banana jack scratch...

And I could have my poly modular with reasonable panel sizes...

But here's another question. Some of those jacks connect the ground wire to the screw on the front and to the panel (mechanically if not electrically)... so it might get some mondo nastiness that way...

Is it easy to locate 1/4" Stereo jack sockets that mechanically and electrically isolate the ground connection as well as the two main signal connections?

What does someone experienced think of my idea? 3 signals on every wire?

Any problems I'm not thinking of or should this work fine?

Thanks,

Jeannine

fluxmonkey · Joined: Jun 24, 2005 Posts: 708 Location: cleve

no offense, but i feel like i came in on the tail end of a conversation with yourself... what are you talking about/trying to accomplish?

magman · Joined: Feb 04, 2009 Posts: 363 Location: Liverpool, UK

You can definitely get insulated Jacks, where the barrel connection is insulated from the front panel.

http://uk.farnell.com/switchcraft/114bx/phone-connector/dp/1298186

You may also be able to get 4 connection jacks in some cases.

I guess you are wanting to patch all channels of a polysynth in parallel (VCO output to VCF input for example), but you may have some issues using jack connections as they effectively short some inputs as the jack is inserted and removed.

You might be better looking at something like DIN Sockets, or Mini-DIN's (like the older style PC Mouse and Keyboard connections), especially as you can get these with up to 8 connections in a small shell. These are available in panel mounting formats like this:

http://cpc.farnell.com/pro-signal/psg01574/socket-4-pin-mini-din/dp/AV15032?Ntt=av15032

You can also get regular sized DIN sockets in a neat panel mounting format, at up to 8 way:

http://cpc.farnell.com/deltron/650-0800/8-pin-panel-socket-din/dp/CN00078?Ntt=cn00078

And another good thing for DIN connections, is that the ground connection is in the outer shell, so a ground connection is normally made before the signal connection.

Hope this helps

Regards

Magman

neandrewthal · Joined: May 11, 2007 Posts: 672 Location: Canada

If you build a poly modular, you will be my idol.

slabman · Joined: Sep 01, 2005 Posts: 102 Location: UK

RJ45s like in ethernet cables. everything - plus, sockets, cable, crimping tools - is dead cheap. you'll have 8 conductors. cable is shielded. you can even buy ready made patch bays on 19" racks.

next question please...

phdinfunk · Joined: Jun 04, 2008 Posts: 119 Location: Taiwan

I don't think shorting connections as I'm inserting a cable should cause any problems since it would effectively be cross-patching the synthesizer but with connections that are "okay."

In other words, if I'm running an LFO to a VCF, do I care if for a half second voice 3's LFO is running to Voice 2's VCF, etc?

The nice thing about 1/4" jacks versus all the other options (which I considered mini-DIN but the RJ45's I never thought of), is that I can get heavy duty 1/4"-ers that will be okay for all the insertions and removals that modular patching tends to lead to....

I think I'd wear out DIN's and mini-DINs pretty fast.

--Jeannine

BOB-SNARE · Joined: Sep 26, 2008 Posts: 30 Location: Australia

Some won't like this idea of sampling but...
You could always look into Time Division Multiplexing over a 1/4" jack.
That way an input attenuator will attenuate all polyphonic signals, and monophonic signals (let's say an LFO) could be used to modulate all polyphonic signals too (say VCO freq).

phdinfunk · Joined: Jun 04, 2008 Posts: 119 Location: Taiwan

Mooger5 · Posted: Sat Sep 12, 2009 4:49 am Post subject:

I´ve seen mini-jacks with two rings lately. Supposedly for 2.1 audio systems. So it´s a stereo jack plus 1. I don´t know what they´re called, but you could ask at DIYAudio.com (electronic parts sub-forum). Good luck.

magman · Joined: Feb 04, 2009 Posts: 363 Location: Liverpool, UK

phdinfunk · Joined: Jun 04, 2008 Posts: 119 Location: Taiwan

Those are super.

I think that will be exactly what I want...

and a nice standard cable that I'll be able to find relatively easily also...

(As opposed to four pin XLRs or some such wierdness)

--Jeannine