In article ,
Fred 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

Low power resistors cost a fraction of a penny in bulk. Probably not much
more than connecting wire.

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?

This sort of socket is usually designed to drive stereo headphones of
approx 25 ohms as a maximum load. If you're using it to drive a mono amp,
the actual source impedance isn't critical. It you were using it to drive
mono headphones, they would likely be high impedance devices. So again,
not much concerned about the source impedance. If you were trying to drive
a loudspeaker, all bets are off. ;-)

--
*I love cats...they taste just like chicken.

Dave Plowman London SW
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