Repairing a set of Koss Pro 5Q quad headphones

Help Support QuadraphonicQuad:

tonyE

Active Member
Joined
Feb 12, 2018
Messages
77
I got two pairs of 70s quad headphones: Koss Pro 5Q and Panasonic EAH-41.

The latter are in absolute NOS condition, the former are in very good shape, EXCEPT that one channel is not working. The jacks and cables look good and but I don't know how to open the shell and they are in such good shape I don't want to damage them.

I called the Koss factory and they had no clue....

...Do any of you know where I could have some one look and fix them?
 

soesbeout

300 Club - QQ All-Star
Since 2002/2003
Joined
Nov 1, 2003
Messages
382
Location
Florida
I recall a member on one of my FB audio groups say that Koss had a lifetime warranty on certain headphones models and would repair for the cost of postage to ship.
 

par4ken

1K Club - QQ Shooting Star
QQ Supporter
Joined
May 28, 2011
Messages
1,742
Location
NW Ontario
I got two pairs of 70s quad headphones: Koss Pro 5Q and Panasonic EAH-41.

The latter are in absolute NOS condition, the former are in very good shape, EXCEPT that one channel is not working. The jacks and cables look good and but I don't know how to open the shell and they are in such good shape I don't want to damage them.

I called the Koss factory and they had no clue....

...Do any of you know where I could have some one look and fix them?
They are simple to take apart only four Philips head screws in each earcup. Once open you just have to ohm out each driver, you will likely find one that is open. Ohm out the cable as well as the 2ch/4ch switch, could be a problem there. It's sad that Koss won't repair those or sell replacement parts (but their new stuff has a full warranty). I have purchased a number of Koss Quad headphones over the years and found that they all have the same or similar drivers except for the Phase 2+2's. So you should look for another pair, any model that you can find cheap or not working and strip out a working driver. The drivers are held in place by three small screws with a hex head.

The liquid filled ear cushions are often flat, you can find inexpensive foam filled replacements on eBay, but it takes a bit of searching to find the right size.

After stripping drivers from the parts phones I fixed them (the parts phones) using modern drivers but found that often it's hard to find good sounding ones.
 
Last edited:

quadsearcher

900 Club - QQ All-Star
Joined
Nov 8, 2010
Messages
984
I think I saw it somewhere on this forum, that some screws that look Philips are actually JIS. Especially in Japanese made equipment. List of screw drives - Wikipedia Might make a difference in trying to drive it out of plastic threads, if Philips wanted to strip out.
 

par4ken

1K Club - QQ Shooting Star
QQ Supporter
Joined
May 28, 2011
Messages
1,742
Location
NW Ontario
Whatever they actually are I have never had any trouble removing them, they just screw into plastic!
 

MidiMagic

1K Club - QQ Shooting Star
Joined
Jul 5, 2010
Messages
1,064
I couldn't repair my Koss phones. The plastic deteriorated and they shattered.
 

tonyE

Active Member
Joined
Feb 12, 2018
Messages
77
I couldn't repair my Koss phones. The plastic deteriorated and they shattered.
I was very lucky with both of these phones, Koss and Panasonic. The latter came from a estate sale and had NEVER been used, they actually came in the original box! The Koss looks extremely well too. The ear pads are still fresh and soft and there are no scratches anywhere. The plastic looks pristine, which is why I was surprised that one channel wasn't working.

I've had both since ~'01 or so.
 

Doug G.

2K Club - QQ Super Nova
Joined
Jul 8, 2007
Messages
2,298
Location
Austin, Minnesota
The thing with screws into plastic is to stop tightening them just before you think you should. That will avoid stripping the threads.

Of course, if they were stripped in the factory, you have to take alternate measures.

Doug
 
Top