In article ,
says...

On 09:02 25 Nov 2016, MJC wrote:

In article ,
says...

On 22:03 24 Nov 2016, MJC wrote:

In article ,
says...

I'm impressed. In some other groups I've been asking about
a one-piece stereo to mono headphone adapter. I want one
with a built-in switch but even though it's not available I
don't think I'll be doing that to fit one!

http://al.howardknight.net/msgid.cgi?ID=148001642200

If, as in link, it has a mono socket, what is the
"mono/stereo" switch going to do?

Mike.


It would allow stereo headphones to play mono in both channels
(rather than in just the left channel) from a mono socket.

You're going to need a stereo socket for that! (I had hoped you
would work that out for yourself with my prompting!)

Mike.

One scenario I need to handle is when I want to play the output
from the headphone socket of a mono dictation machine on both
channels of stereo headphones.

At other times, the need is to pass through a stereo signal from a
stereo socket to stereo headphones and then to switch over to
hearing dual mono in the headphones.

It's all lovingly discussed in the thread in uk.d-i-y. :-)
MID:

Sorry, I don't feel loving enough to read that. If you don't understand
the need for a stereo socket, I give up!

Mike.