On Wed, 16 May 2012 14:02:07 +0100, "Dave Plowman (News)"
wrote:


It rather depends. Amplifier outputs are usually low impedance and may not
like being connected in parallel. So to be safe you'd use a resistor in
each leg to prevent distortion. Going the other way round - mono to
stereo, so two inputs are connected - is usually ok.

I doubt these adaptors have resistors built-in, do they? It would add
complexity and cost to the design and I suppose the value of the
resistor would have to match the impedance of whatever it was
connected to, so the manufacturer would not be able to produce a "one
size fits all" item, or would they?

You'd be hoping the single tip mates with the twin stereo contacts. Which
it may or may not do reliably.

I think when I typed that a mono socket would short both channels
together I was thinking of the contacts in the socket touching the two
sections nearest the barrel end of the plug. Now that I think about
it, I think that ground is nearest the barrel, then right, then left
channel, in which case, wouldn't the right channel be shorted to
ground rather than to the left channel? Perhaps an adaptor is required
after all and I suppose for forty pence, better safe than sorry.

As it happens, I was looking for something completely different when I
stumbled across these, so it is all hypothetical but hopefully might
help somebody else.

I actually ordered a set of twin leads with phono plugs both ends to
carry left and right audio. The leads have arrived and on each plug is
printed the word "digital"! The mind boggles. Clearly a case of the
marketing department adding the word "digital" to make it sound
superior! I've gone and had a look at them and yes, they are gold
plated too