[edwardsean]

Hi.

I recently finished a small interconnect project using canare f12s. The terminal contacts don't have holes which force the wire to be wrapped around and soldered. I'm ordering some Cardas Quad Eutectic for another project but at the time I only had some cheap stock solder. I am considering resoldering the connections with the Cardas. But since there is direct mechanical contact between wire and connectors, would it still make a difference in sound quality. I did some searching on the site but couldn't find a good answer. Thanks for any help.

Sincerely,
Edwardsean

 

[nikongod]

this question opens a bag of worms at least as large as whether cables even make a difference.

i personally would not worry about it, but then i make interconnects out of 41ga magnet wire.

 

[Nebby]

A single strand of 41ga? Must make for some seriously compact IC's!

 

[bhjazz]

We're talkin microscopic levels.

The best connections give you the following two things, near as I can tell: a mechanical connection, and an electrical connection. If you are worried about the connection holding, disconnect the two parts and drill small holes for the wire to attach to, then resolder.

Don't worry too much about it. Close them babies up and enjoy them. NOW!

 

[Uncle Erik]

I'd file a notch on either side of the tab, wrap the wire around, and give it a quick little solder.

I don't know if it will make a difference in sound quality, but you will get an excellent mechanical and physical connection. It's worth it for durability and strength, at the very least. If you can overbuild with little cost of time or money, you always should.

 

[FallenAngel]

If there is a good mechanical connection, that's all that matters, ideally solder would not even be conductive, it's just there to hold things in place, not to send electrical signals. Use whatever is easiest, that proves to have best results

 

[Budgie]

The general rule is to make a good mechanical connection then solder it.
Is the solder is really needed? Maybe. Depends. Mechanical only connections do tend to develop oxidation issues that solder helps to prevent, but if it is a compressed mechanical connection, such as a crimp or screw terminal (tight enough to prevent oxygen creeping into the junction between the metals) then the solder is not going to make a difference.

 

[kipman725]

when soldering components they should have mechanical contact anyway. The solder should only be used to hold them togehter and increase the surface area and also stop the two surfaces devolping non conductive oxides/coatings. I would recomend using your "cheap" solder, silver solder melts at a higher tempreature anyway.

 

[error401]

If you really want, build your amp with wire wrap and don't use any solder at all. The tension is enough to cold-weld the wire and pin.

 

[tyre]

Quote:

Originally Posted by kipman725 /img/forum/go_quote.gif when soldering components they should have mechanical contact anyway. The solder should only be used to hold them togehter and increase the surface...

Gah, I disagree completely. I still have no idea why people recommend this. What about surface mount components? They are held on to the PCB 100% by solder, no "mechanical" contact whatsoever. Granted, non-surface mount components tend to have more mass than SMD components, but unless we're talking about some massive heatsinked power package IC/transistor, I still doubt that mechanical contact matters one bit as the components weight is still small.

Interconnects are probably the only application where "mechanical" contact is actually needed since they are prone to be pulled on frequently. But even then, I would still solder the connections because there isn't a good reason not to.

 

[kipman725]

Quote:

Originally Posted by tyre /img/forum/go_quote.gif Gah, I disagree completely. I still have no idea why people recommend this. What about surface mount components? They are held on to the PCB 100% by solder, no "mechanical" contact whatsoever. Granted, non-surface mount components tend to have more mass than SMD components, but unless we're talking about some massive heatsinked power package IC/transistor, I still doubt that mechanical contact matters one bit as the components weight is still small. Interconnects are probably the only application where "mechanical" contact is actually needed since they are prone to be pulled on frequently. But even then, I would still solder the connections because there isn't a good reason not to.

no you misunderstand I mean by mechanical contact the pins of the two devices are touching as solder isn't a very good conductor in comparison to copper pcb tracks and therfore would negate things like low ESR capacitors. This isn't such a problem with surface mount because the area of solder is absolutly minute. But with DIY its perfectly posible to get a huge solder blob with the leads ether end of it! that is what I mean is a bad thing. PLuss surface mount devices get better contact anyway due to the large pad surface area (particularly with high frequancy devices which have oversized massive pads )

 

[FallenAngel]

Quote:

Originally Posted by tyre /img/forum/go_quote.gif Gah, I disagree completely. I still have no idea why people recommend this. What about surface mount components? They are held on to the PCB 100% by solder, no "mechanical" contact whatsoever. Granted, non-surface mount components tend to have more mass than SMD components, but unless we're talking about some massive heatsinked power package IC/transistor, I still doubt that mechanical contact matters one bit as the components weight is still small. Interconnects are probably the only application where "mechanical" contact is actually needed since they are prone to be pulled on frequently. But even then, I would still solder the connections because there isn't a good reason not to.

Uhm... SMD components completely have mechanical connections to the PCB, they're lying on top of them and there is metal on the sides of the component which are touching the PCB.

Perhaps we have another understanding of "mechanical connection", to me it does not mean that there must to be pressure there, just that the two components are in physical contact of each other.

 

[error401]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif Uhm... SMD components completely have mechanical connections to the PCB, they're lying on top of them and there is metal on the sides of the component which are touching the PCB. Perhaps we have another understanding of "mechanical connection", to me it does not mean that there must to be pressure there, just that the two components are in physical contact of each other.

I believe the desired effect with SMD devices is that they 'float' on a few um of solder.

If two metal components are lightly touching, oxides will develop on both surfaces. Oxides are generally really horrible conductors. This is the reason solders need flux, to clean the oxides off the metal so the solder can bond properly. Connecting conductors without solder requires enough mechanical force to cold weld the metals so oxygen can't enter and oxidize the joint. Crimped joints and wire wrap work this way. Lightly placing an SMD part on a board doesn't.

I'm not sure what you mean by solder being a bad conductor. We're talking about probably a few um to a mm at most of conductor, with a relatively large cross section and surface area. For most joints it's probably a better (read: closer to ideal) conductor than either of the conductors it's joining. I suppose it does have a minutely higher resistance, but the cross sectional advantage should easily counter that for everything but huge circular conductors.

But hey, this is audio. Do what sounds good to you!

 

[FallenAngel]

Quote:

Originally Posted by error401 /img/forum/go_quote.gif I believe the desired effect with SMD devices is that they 'float' on a few um of solder. If two metal components are lightly touching, oxides will develop on both surfaces. Oxides are generally really horrible conductors. This is the reason solders need flux, to clean the oxides off the metal so the solder can bond properly. Connecting conductors without solder requires enough mechanical force to cold weld the metals so oxygen can't enter and oxidize the joint. Crimped joints and wire wrap work this way. Lightly placing an SMD part on a board doesn't. I'm not sure what you mean by solder being a bad conductor. We're talking about probably a few um to a mm at most of conductor, with a relatively large cross section and surface area. For most joints it's probably a better (read: closer to ideal) conductor than either of the conductors it's joining. I suppose it does have a minutely higher resistance, but the cross sectional advantage should easily counter that for everything but huge circular conductors. But hey, this is audio. Do what sounds good to you!

Hmm.. learn something new every day

I always assumed when two things are touching you'll have a better connection than putting solder between them. When I built a few amps on perfboard and used solder instead of wire leads to make connections, there was a lot more noise in the circuit so I concluded that solder isn't the best for making connections. I also had better connections (less problems in AlienDACs/PPAS/PINT) when I soldered SMD and then removed 99% of the solder using desoldering braid.

 

[Lazarus Short]

Some years ago, I mentioned the wire-wrapping technique used by Pioneer and other manufacturers to someone I knew, who had a lot of experience in electronic repair. He said that it saved money in manufacture, but cost more in warranty claims. More recently, I sold some Pioneer gear to this same fellow, a tuner, a SPEC pre & power amp, and they had been stored in a basement, or some other damp place. The innards were well oxidized, including those wire-wrapped connections. I didn't get much for the gear. Now, before you remonstrate with me, I was selling them for a friend - not my gear, not my damp.

Laz