help - making patch cables, not working

Jtaylor

So I've soldered up patch cables for my pedalboard, using hicon jacks and mogami cable, ive had to use switch craft 226 jacks for the cables for strymon pedals, I've just soldered this one up, and its not working properly, any ideas why? I've tried re doing the solder joints but no change, i cant figure out whats wrong, all the cables I've soldered from hicon jacks have worked fine but this doesnt

SteveRobinson

Could the lower one be shorting? The wire looks like it's poking through a bit too much and when you put the cover on it might press them together, shorting the lead.

Also it looks like the twisted braid on the top one might short against the other terminal. Put some heat shrink over to be sure it's insulated.

Jtaylor

Just tried both, neither solved it, the cable does work, but theirs loads of hissing in the background, Its nearly as loud as the guitar! Any ideas? 

ICBM

Looks like you've done the pancake jack the wrong way round. The braid should go to the casing.

You may also have not stripped the black semi-conducting layer back far enough on the standard jack - if there is one. It must not touch the centre terminal. It's a very thin layer on top of the insulating plastic.

Jtaylor

I've soldered all the other pancake jacks like it and they have all been fine? 

I tried the removing more of the black layer back but no change unfortunately 

steamabacus

Yes, the pancake jack looks to be soldered screen-to-tip and signal-to-ground. It looks like the braided screen is in danger of shorting to the tip connection as well.

ICBM

Jtaylor said:

I've soldered all the other pancake jacks like it and they have all been fine?

I don't know how, because it's definitely the wrong way round.

Unless the other cables have pancake plugs at both ends, in which case the cable will work but won't be shielded because the hot is on the outside.

Jtaylor

ah man, thats really annoying, here are some more pictures of it... 

I just soldered it how the previous owner of them soldered them as i bought them second hand on here and the previous owner left a bit of cable on each jack so i just followed how he did it  

ICBM

Yes, absolutely no question that is the wrong way round.

If that wire does have a semi-conducting layer you do really need to strip it back a bit too.

Jtaylor

ah, ok, which wire is the one i need to strip back? 

Jtaylor

just switched it so its the other way round, all sorted now, thanks so much everyone

ICBM

Jtaylor said:

ah, ok, which wire is the one i need to strip back? 

The thin black one. There should be a (usually) clear or white plastic layer underneath it, be careful not to damage that.

Most of the time it doesn't actually matter if you don't do this, but sometimes the black layer can touch the solder on the joint and then it will partially short the cable, usually making it very muffled-sounding and quiet.

Jtaylor

thanks @icbm, have been doing that on all the cables now, your right, i wasn't sure why some of the cables i were making would do that, havnt had any do it since striping the black covering off. 

sweepy

Conductive sheathing can be a real pita, Klotz cable being a prime example

ecc83

Glad all is sorted.

Tip with the pancakes, put some threadlock on the tiny screws (or pinch some of 'er nail varnish!)

I liked to put heat shrink over them but then I had access to all sorts of sizes for free!

Dave.

joeyowen

So if they were the wrong way round on the other cables, we're you passing signal over the braid?

Wonder if that would affect toanz

ICBM

joeyowen said:

So if they were the wrong way round on the other cables, we're you passing signal over the braid?

Wonder if that would affect toanz

I wouldn't think so, because the core-to-braid capacitance would be the same. But it would definitely increase noise because the signal conductor would then be on the outside - how much, might not be very noticeable over a typical patch cable length and especially if after a buffered pedal. But still not a great idea.

I did try some hi-fi inconnects once that were made from unshielded cable - but not shielded cable reversed, it was actually VHF aerial cable, hence with extremely low capacitance - and definitely did improve the sound while not adding any noticeable noise, but that was with fully buffered line-level signals from a CD player to the power amp.