[tin ears]

I have a pair of standard issue, dynamic style headphones I am going to hardwire directly to my headphone amp by eliminating the phono plug male and female ends.

Now each headphone transducer has two 24g wires attached to it. The right side has one black wire and one red wire. The left side has one white wire and one black wire.

The amp in question has (once you eliminate the phono plug female end) to the phones, labeled on the PCB board, one wire labeled left, one wire labeled right, and one ground. Each amp wire is 2 and 1/2 inches long and all three are soldered directly to the PCB board.

How would you all connect the three headphone amp wires (left,right, and ground) to the four headphone wires (red/black and black/white)? Seems like lots O' combos possible.

Choose and lose, trial and error, or is there a method to the madness????

 

[eddiewalker]

I have NO idea why you would want to do this, but if you insist, connect both black wires to the amp's ground, and the other two wires to left and right respectively.

 

[Zorander]

Not a very practical idea but it's your gear.

 

[colonelkernel8]

The only time that this is acceptable is typically with K1000's, because of their "earspeaker" nature. They are sometimes hardwired to a speaker amp.

 

[tin ears]

Let's try to think outside the box for a second and hold off on judgement for some discussion on the problem at hand.

Eddie Walker
I tried your obvious and intuitive method, but with this headphone/ amp combo, it failed. Both blacks to amp ground and white to left and red to right produced normal sound in the left and reduced sound in right with major echo in the right.

Removing both grounds?/black wires from amp and tying them together with left and right still hooked to amp produced a mono like, but relatively normal sound from both transducers.

Any other ideas or theories?

This absolutely has to work in some other way. The thing worked with the male female phono plug set up.

 

[eddiewalker]

If you previously had it wired with a 1/4" jack, then from the end of the connector up, whatever went to the tip is left, ring is right and sleeve is ground.

A continuity tester could be very helpful in this situation.

 

[tin ears]

Eddie,

Thanks for the continued input. It is appreciated. Again your advice is sound and I had thought of doing just that, however, it turned out to be impossible to remove the phono plug off the headphone cord. I destroyed the plug in the process. I ended up having to cut the cord off the plug. These are the new Denon phones, if that helps at all. The plug was not meant to come off. It was a 1/8 inch with a 1/4 inch adapter.

How would a continuity tester help in this situation? Shouldn't there be some standard simple way to hook the 4wires from the phones to the 3 wires from the amp, other than the obvious one we already tried?

 

[Old Pa]

It's not worth it. You are not going to want to use one set of cans with one amp for long. Just clean and condition your plug contact surfaces with the appropriate CAIG product and enjoy good sound while leaving them as they were designed to be.

 

[labmat]

Quote:

Originally Posted by tin ears /img/forum/go_quote.gif Eddie,How would a continuity tester help in this situation? Shouldn't there be some standard simple way to hook the 4wires from the phones to the 3 wires from the amp, other than the obvious one we already tried?

The continuity tester would allow you to determine which color wire went the tip/ring/sleeve. You would have done this by touching one probe to tip/ring/sleeve and then touching the other probe to the ends of the wires you stripped and jotting down what was connected to what.

 

[n_maher]

It is worth noting that there is probably enamel on the wires preventing them from making good contact. Just about every stock headphone cable I've ever worked with has had this.

 

[tin ears]

Labmat,

That would have been very helpful.............two days ago. The headphone cable is bare and the plug is destroyed. I have 4 wires to hook up to 3 wires.

N maher,

the wire has no enamel on it. Each of the 4 headphone wires is very very fine multi stranded 24 g, half of the 24g is actually composed of equally fine threads of a nylon like substance that runs along continuously with the copper strands. In fact, once I isolated the actual copper wire from the nylon threads, it is more like 30g copper stranded wire. Each of the 4 wires is amazingly/surprisingly thin from an 9 ft long conductor point of view. Perhaps the nylon strands are a replacement for the enamel?

 

[n_maher]

If it were me at this point I'd just do a complete rewire rather than deal with both the existing wires (not knowing which are assigned to what) and trying to hardwire the cans to the amp.

 

[Pars]

Quote:

Originally Posted by tin ears /img/forum/go_quote.gif Labmat, That would have been very helpful.............two days ago. The headphone cable is bare and the plug is destroyed. I have 4 wires to hook up to 3 wires.

At this point, you could ohm out each wire to every other wire (or continuity test). to figure out which are pairs going to the same driver. You should have + and - to L driver and + and - to R driver. From there, you only have about 3 different ways to connect them... if you get the drivers out of phase, it should be apparent I would think.

 

[tin ears]

I know which pair is left and which pair is right. Each pair is isolated in its own sheeth all the way up to the transducer. Left side is black and white, right side is red and black. I just don't know which is plus and which is minus. That is from the headphoe point of view. The amp is clearly labeled left right and ground on the pcb board.

If we did know what each wire was, is it correct to assume that both minus wires should be tied together and then to the amp's ground? Then left plus to left on amp and right plus to rt on amp?

N maher, I plan to recable and hardwire that as well, but I want to get a baseline with the original first and of course, I need to figure this little wiring problem out first.

 

[Pars]

Minus wires would have been tied togther at the sleeve of the plug, so...

One other thought... can you see the drivers? If you take a small battery, you could apply it to each pair of wires and observe which way the cone moved. Careful though, as the voice coil wires are tiny and overcurrent could damage them. Mark them whichever way the cone moves out. The + in this arangement should be the L or R and the - will be -.