To terminate.. or not

Has anyone tried, or looked into using an anti-oxidant (the grease-like stuff electricians use) when making audio connections? Seems like it should work: no oxidation, better contact. But....?

Axle - low impedance is only at low frequencies. At RF it appears as high impedance and also as amp's input since feedback is connected there (class AB amp has gain before feedback as high as 4000).

I would suspect that the highest radiation comes from power cables of amps that take high average power (class A). Current in power cables comes in narrow spikes of very high amplitude (it is really a switching power supply operating at 120Hz).

Actually, I was talking about EMI radiating out of the binding post and onto adjacent compnoents/cables. Speaker cable doesn't need to be sheilded because it has low impedance and high current.

Axle - Shielding is a very difficult thing. I assume you're talking about shielding speaker cables from external EMI radiation. I'm not sure that you need to shield speaker cables but in general shielding works a little different than we think. Shielding material of interconnect is non-magnetic but it is shielding cable not only from capacitively coupled but also electromagnetically coupled interference (common mode). EMI in fact IS electromagnetically coupled into the cable but because of skin effect it travels (to ground) on the outside of the cable's shield. Field inside of the shield is zero as long as cable is symmetrical/uniform.
When a cable shield is carrying differential mode current, as in the case of coax, skin effect will cause that differential mode current to flow on the inside of the shield.

Yes, should the washer(s) produce an ideal condition whereby pressure is applied relatively uniformly across the contact surface area - voila! :-)

Vbr,
Sam

You can shield the entire cable to reduce radiated EMI except for the termination. So how do you reduce radiated EMI at this point? The answer may be geometry of the termination. You probably want something flat and wide because it dissipates the magnetic field versus something long and narrow that concentrates the magnetic field. This is one possible reason for a spade over a banana.

Yes, surface area makes sense. But do you really get contact over the entire surface? Both the spade and the binding post are probably not as flat as they may seem to the naked eye. The result is contact only on highest spots of the top surface and the lowest spots of the bottom surface. But if you add a lock washer on top of a star washer, now you are guaranteed surface area coverage plus tension force.

Hi Axle,

I believe one rational for spade connection is it affords greater surface area for electrical contact.

Regards,
Sam

I'm sure they work great for most and they are a nice design. I was hooking up 4 spades into each one which I found to be a hassle, much easier with standard type binding posts.

Rja - Why? They are the best invention since sliced bread. My cable is very thick and heavy but it cannot get unscrewed. Traditional post can get loose with rotation of the wire but Cardas Clamp cannot - it is very strong and secure. I also love big knob I can tighten securely without any tools.

Are we talking about the same connector? Check second picture: http://www.audioenz.co.nz/2007/rowland_capri-102.shtml

Kijanki,
I had those Cardas on my amp. They drove me crazy. I had them removed.

Makes no audible difference make selection based on convience

"Can someone please tell me one good reason why to use spades?"

Many amps don't allow bananas. I used to have Cambridge A3i amp that allows only spades (no hole in the post). Now I have Rowland model 102 that has Cardas clamp style (with one big knob) terminal for spades only. Whole new lineup of Rowland amps might have it.

It depends on your requirements. The best connection is to solder because it eliminates the #1 problem of contact reliability, which is tension force. Obvisouly soldering is not always an option and you must connect meachanically. In which case, bare wire offers the best reliability. If it is a semi-permanent connection, like at the speaker, then there is no reason not to use bare wire. The problem with bare wire is that strain releif is next to impossible. If you are going to plug/unplug often, like at the amp, then bare wire can stress, fray, break. In which case, you probably need a connector for strain releif as well as convenience. Going back to rule #1, select a connetor that offers tension force. That would be a locking banana.

I hear so many people say that spades offer the best quality. But I never hear a reason why. My experience has been poor. Can someone please tell me one good reason why to use spades?

Now that we are on the topic, why don't they put lock washers on bidning posts? That would apply tension force to hold both bare wire and spades in place.

Solid wire unterminated. No stray strands to worry about. Just as bad as the stray strands are the loose banana plugs... killed a channel that way. Spades over bananas if you can, but bananas for simplicity. Bare wire is first choice though.

I think,-silver - Bananas are the best way to go. The contact area is in the plug.

Not every amplifier accepts bananas. Consider spades at least on amp side. From the purist's point of view spade provides the best sound but it's probably way above level of your gear and cables.

In my opinion BFA style bananas are the best compromise. They always fit tightly, but without the need to "lock" them. Because they maintain constant outward pressure onto the inside of the speaker binding post, they are "self-tightening. This is a huge benefit over bare wire or spades which can loosen over time.

BTW, you can buy BFA style bananas very inexpensively at Multi-Contact USA. I think they are $1.11 each. Here's a link to an excellent review of a DIY speaker cable that uses the Multi-Contact USA BFA style bananas:

http://6moons.com/audioreviews/whitelightning/moonshine.html

Enjoy,

TIC

Jea48:
When choosing between spades or bananas, is one connection type thought to be better than the other?

I'm not interesting in obsessing on this one. Rather, I want to order some stuff and listen to some music on my new speakers!
Headshrinker2 03-04-09

Then go with spades or banana plugs.
With bare wire there is always the chance of strands of the + & - coming into contact with one another at the terminations. Can be bad news for the power amp.....