ribbon cables

[juniorhifikit]

Ribbon cables seem to get a bad rap from people posing as designers on the ol' web (like myself). Can anyone shed any light on this dark voodoo? Is it a matter of capacitance? Are there any good ribbon cables? I see them in quite a few "pro" pieces despite their bad reputation...

[mediatechnology]

Didn't we cover some of that here?

viewtopic.php?f=6&t=379&hilit=ribbon+cable&start=10

I never cared for them much and in older products with the open-ended IDC. I did have issue with them failing.

The SSL is full of the computer-grade but those were conventional 3M ribbon cables used for control and I never had any issues.

[juniorhifikit]

I was hoping I might use them as interconnect between two boards to give me a little "play" when positioning. This would be about an inch long and carry unbalanced audio from a 5534 on one board, to a resistor summing network on another board - soldered on both ends.

[mediatechnology]

If you do decide to use ribbons for unbalanced audio I'd interdigitate ground with signal to reduce crosstalk. With it soldered on both ends you eliminate the "connectoritis" problem. I can't remember which brand of console I used to work with that used these for bussing power and mix buses but I was always having to strip back the insulation and solder the termination where it looped through the connector. (Was it Tapco?) The console was an intermittent pig.

[juniorhifikit]

... or I could just get my chassis measurements right and use headers.

[JR.]

Ribbon cables seem to get a bad rap from people posing as designers on the ol' web (like myself). Can anyone shed any light on this dark voodoo? Is it a matter of capacitance? Are there any good ribbon cables? I see them in quite a few "pro" pieces despite their bad reputation...

The main rap against ribbon cables is integrity of the IDC (Insulation displacement) electrical circuit. There are a number of anecdotes of product problems caused by bad ribbon cables. This ignores the bazillion of these that have been used with little/no problems.

I've used tons of these in products with no complaints, but in production if you are making your own cables it takes attention to detail and process... The tooling can get out of adjustment, and wiring insulation thickness can vary... I would be very apprehensive about buying these made by somebody else and sold by a third party, not to mention the who knows what quality wire stock coming from guang dong.

As Wayne mentions you can interdigitate grounds for some extra shielding if passing dissimilar signals in adjacent lines. I've used these for buses in consoles and for virtual earth summing there shouldn't be any voltage on the wires to crosstalk, while the capacitance may be larger than with loose cable bundles.

These are widely used and "shouldn't" be a problem..

JR

[juniorhifikit]

That's what I was hoping to hear. As Wayne had mentioned, interspersing ground between signal wires will reduce cross-talk. Sounds like a plan...