Repairing headphones.

[DizRotus]

How many times have the TRS connectors on headphones or IEMs failed?  The TRS connectors themselves, typically, do not fail, but the fragile wires to the tiny molded plugs fail from constant flexing.

 

The leads are tiny and frequently involve stranded wires intertwined with fibers providing strength and flexibility.  Soldering such ephemeral wires is problematic.  After limited success, I have discovered some strategies that result in viable connections that survive continued use without making the cables too bulky.

 

First, I buy male to male Amazon Basics TRS cables to cut in two to be used as the new connectors.  The cables are inexpensive and have real stranded copper wires that are more easily soldered to the fragile leads of the IEMs or headphones.

 

Some leads are stranded wires with each strand coated in lacquer.  Some leads are individual strands without the coating.  Almost universally the strands are intertwined with non-conductive fibers for strength and flexibility.  Before exposing the strands, it’s necessary to strip away the outer insulation without severing the gossamer leads within.

 

Yesterday I repaired a pair of Sennheiser headphones with a bent TRS plug.  The black outer insulation contained four tiny individual leads; black, white, red and blue.  Stripping the colored insulation away and teasing the wire strands away from the fibers, was difficult.  Success with the first three was undermined by accidentally severing the fourth.  After several failed attempts to successfully strip away the insulation from all four leads, just before throwing the headphones in the trash, I tried something thing new.

 

Rather than trying to strip away the colored insulation, I put the lead in an alligator clip with ~1” hanging out.  Using a match, I burned away the colored insulation and the fibers.  After gently twisting the remaining strands, which knocked away the ash, the leads are twisted together with the strands from the Amazon cable and soldered together.  Naturally, heat strink tubing is installed before the wires are twisted together.  The danger with these fragile, less than ideal, soldered connections is a complete absence of mechanical integrity.  The liberal use of heat shrink tubing and zip cable ties relieves the soldered connections from any need to withstand tension.

 

This technique works with any type of headphone or IEM lead, but the resulting fragile soldered connection must be protected by heat shrink insulation and folding the wires back on themselves to prevent any and all tension from reaching the soldered joint, they will fail if ANY strain is applied.

 

The technique worked so well, rather than toss the Sennheisers in frustration, I took the opportunity to convert them to “balanced” to use with a Pono player in balanced mode.  This meant soldering a separate Amazon Basics TRS plug to each pair of leads.  To confirm which leads went to which earpiece, A battery (AA) was used to produce a scratching sound in the earpieces.  FWIW, I have an adaptor to use the now balanced headphones with SE (single ended) sources, such as an iPad.

 

Photos will be posted later when I’m at a proper computer to be able to resize them.

 

 

[Schu]

Four pole balanced?

 

Your braver than I... I have the worst luck with soldering.

[Marvel]

Neil, an alcohol flame would burn cleaner, or perhaps even a butane lighter.

 

I've always hated those thin cables.

 

Bruce

[DizRotus]

Thanks for the suggestion Bruce.  I actually have a butane soldering iron that I could/should have used. Next time.

 

The attached photo shows the black rubber encased cord on the Sennheisers with the four tiny leads within.

 

[DizRotus]

This photo shows a single lead prior to burning.

 

[DizRotus]

The burn in progress.

 

[DizRotus]

The burn completed.

 

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The lead and hookup wire twisted together.

 

[DizRotus]

The soldered joint.

 

[DizRotus]

Lacquered leads on a cheap pair of headphones.  I've found that the heat of soldering removes the insulation allowing an electrical connection, but a very weak mechanical connection.  These "repaired" joints must be strengthened by using heat shrink insulation and cable ties to eliminate any strain on the solder joint.  I'll try the butane torch on these, but I must wait until more Amazon Basics TRS cables arrive.

 

I won’t bother to convert these PE cheapies into balanced.

 

 

 

[DizRotus]

The repaired and now balanced Sennheisers.  The four colored twisted pairs of hookup wire replace the coil cord 

 

[DizRotus]

Connected in balanced mode.

 

[DizRotus]

Using the adaptor to connect the now balanced Sennheisers to Pono in SE mode.

 

FYI, the white and red heat shrink insulation is used to identify which cable connects to which.

 

[DizRotus]

@Schu Lots of failures preceded success.

 

[DizRotus]

1 hour ago, Marvel said:

Neil, an alcohol flame would burn cleaner, or perhaps even a butane lighter.

 

I've always hated those thin cables.

 

Bruce

 

Hate is too mild a word.

[DizRotus]

Having the Sennheiser cans available allowed me to get the impressions of my wife and son regarding balanced (DIFF) versus single ended (SE). For some reason, test subjects are much more eager to put on over-the-ear headphones than to use someone else’s IEMs.  Go figure.

 

Both repeatedly identified and preferred the DIFF.  They agreed the SE sounded very good, but DIFF sounded better.  Right @rhing?