Why don't my DIY patch leads work?

Hi all,

I've been making my own patch leads and guitar cables recently, but they seem to be very inconsistent. Some of them sound great, but others seem to cut the guitar's signal by as much as half, and I'm not sure why. I've soldered the heck out of some of the joints, but still they don't work too well.

Is there some secret trick to soldering that I'm missing? I'm using good quality parts (Neutrik gold jacks and Van Damme cable) so this has really got me stumped. :confused:

Would be grateful for any hints you might have :grin:

I've soldered the heck out of some of the joints, but still they don't work too well.

Probably too much solder, too heated, bad contact.

Just out of interest, what effect does 'too much' heat have?

Simply put, too much heat can damage what you are joining, making the wire and/or component less able to conduct. But let Wikipedia explain it:

"Various problems may arise in the soldering process which lead to joints which are non functional either immediately or after a period of use. The most common defect when hand-soldering results from the parts being joined not exceeding the solder's liquidus temperature, resulting in a "cold solder" joint. This is usually the result of the soldering iron being used to heat the solder directly, rather than the parts themselves. Properly done, the iron heats the parts to be connected, which in turn melt the solder, guaranteeing adequate heat in the joined parts for thorough wetting.

An improperly selected or applied flux can cause joint failure, or if not properly cleaned off the joint, may corrode the metals in the joint over time and cause eventual joint failure. Without flux the joint may not be clean, or may be oxidized, resulting in an unsound joint.

Movement of metals being soldered before the solder has cooled will cause a highly unreliable cracked joint."

The trick is to have clean surfaces, heat the parts, use a heat sink when necessary, use proper heat, do not move the joint before it's cooled (ie don't "test" it by flexing it). Repeated resoldering weakens/corrodes the parts.

Mike Bruce

I'll assume you're using instrument cable or some form of coaxial cable? Please say you're not using speaker cable or some other form of 2 strand wire.
That would certainly make things sound a bit off.

Sometimes excess heat can speed oxidation of the conductors which can cause bad solder joints.

Generally:
-Keep the surfaces to be soldered clean. Rubbing solid-core wire on a little steel wool can help
-Keep exposed wire as short as possible
-Use as little solder as is necessary to achieve the joint
-Do it over again until you feel like it's a job you want to show off

People have run into such problems with Mogami cable, and a quick visual check at Van Damme tells me it might be a similar situation. From Mogami's site:

Most musical instrument sound pick-ups, for example those in electric guitars, are comprised of high impedance circuits driven mainly by voltage, with very little electrical current flow. That is why handling noise (microphonics) can be a problem for guitar cables. Microphonic noise is caused by the minute voltage generated when a cable is flexed, stepped on, etc. Guitar cables must be designed to prevent this, so a conductive PVC layer is placed under the shield conductor to drain away this voltage. Note: This conductive layer must be stripped back when wiring, or a partial short will result.

In other words, the black stuff around the insulation around the center conductor looks nonmetallic, so people sometimes think it's plain old insulation and let it touch the conductor. It looks like the Van Damme may have a similar layer, and maybe it's touching on some of your cables.

Thanks for all this, I'll give it another shot.

I've built 20+ DIY circuits and patch cables give me the most fits as well. Misery loves company.

I've built 20+ DIY circuits and patch cables give me the most fits as well. Misery loves company.

It's really starting to annoy me now. I cleaned away all the old solder, got some new stuff and started from scratch, but still nothing :mad:

I disagree with some of the comments about overheating. The biggest danger in overheating cables is in melting the insulation, causing shorts in the cable. Heating the copper conductors and metal jack parts WILL NOT change their "sonic properties". I have soldered thousands of cable ends of all types, and the two main failures are "cold" solder joints and melted insulation.

Get a VOM (meter) and use the OHMS function to check the cable. You should have near 0 ohms from tip to tip and barrel to barrel. You should also have infinite ohms (open) from tip to barrel.

Your problems might not be in the cable itself. Maybe your new connectors are touching the in/out jacks in a "new" place, and corrosion on the JACKS is causing a bad connection. Try using some fine sandpaper to lightly clean the jacks and see if that helps.

denny

I disagree with some of the comments about overheating. The biggest danger in overheating cables is in melting the insulation, causing shorts in the cable. Heating the copper conductors and metal jack parts WILL NOT change their "sonic properties". I have soldered thousands of cable ends of all types, and the two main failures are "cold" solder joints and melted insulation.

Get a VOM (meter) and use the OHMS function to check the cable. You should have near 0 ohms from tip to tip and barrel to barrel. You should also have infinite ohms (open) from tip to barrel.

Your problems might not be in the cable itself. Maybe your new connectors are touching the in/out jacks in a "new" place, and corrosion on the JACKS is causing a bad connection. Try using some fine sandpaper to lightly clean the jacks and see if that helps.

denny

Thanks for the tip, Denny. I think it could be an insulation problem as well - looks like I'm gonna have to just start over with some fresh stuff. Good job it's not too pricey :razz: