Excal headphone endcap wiring?

[bklein]

I received this excal headphone endcap with a red, black, and shield connection. Where does the shield connect to the detector board? Sometimes I see this as a yellow wire - but haven't seen where it goes. Which models use this?

 

[surfman]

If I remember correctly it's a volume limiter. It gets deleted. I'm sure JoeB will chime in at some point and correct me if I'm wrong.

 

[bklein]

No, that resistor and capacitor in the endcap is a AC coupler so that any D.C. Offset in the audio signal is blocked from the headphones - it saves battery draw and should be kept in circuit. I need to know about shield ground - it is the brown thing sticking up slightly in my photo. Probably goes to same place as the black wire but I'd like to know for sure. As I'm putting in a CTX audio jack it probably doesn't matter as you can't count on shielded lines on the phones themselves.

 

[surfman]

Both of my Excal's have been modded with remote pinpoint and modded headphones. To do it you get rid of that single endcap and use a double. Just two wires are all that's needed for the headphones. Mine work and sound great.

 

[OldBeechnut]

No, that resistor and capacitor in the endcap is a AC coupler so that any D.C. Offset in the audio signal is blocked from the headphones - it saves battery draw and should be kept in circuit. I need to know about shield ground - it is the brown thing sticking up slightly in my photo. Probably goes to same place as the black wire but I'd like to know for sure. As I'm putting in a CTX audio jack it probably doesn't matter as you can't count on shielded lines on the phones themselves.

The copper wire goes to capacitor C64..front leg. Blue Box Res & Cap in the circuit, my opinion, not necessary . I think they were added around 1998/99. The copper ground wire was added to the Excalibur 2's.

 

[OldBeechnut]

n/t

 

[AngerManagement]

While things will work OK... If the RC network is removed complete - then any DC bias can get through and that can PRE stress any speaker system. For Pizo's it means they can be bent and thus loose their response performance.

When things are good - no problems...

If you ever end up with a short at the Speaker... Then again the CAP should stop any dc surge current and protect the Audio drivers on the board... NO CAPS and yu could have a board problem.


I use the standard cap but use a POT to determine the best vale resistor for me.

If you look at the maths - and the impedance of the Pizos in // with the resistor etc and the cap across a frequency range that we can hear 1hz to 20Khz... About a 1 x 100 diver network so should be min losses... HOWEVER, depending on the speakers being fitted and YOU own hearing...

It may be a Frequency issue rather than Volume that is the issue...

I found the GG were bad for my hearing range/limits - Koss with some deadening in the cups to stop wind noise was helpful.

I also played with different types and layers of runs of sealant across the back of the Pizeos . As that changes their frequency responce. Some systems had a band of Si around teh side / others were fully covered and at least 3 diferent types from Hard to Soft..

Problem is it takes time to play and what may work for one; may not be OK for another...

Such is life.