['LIVEWIRE?']

As a follow-up to all the foregoing, and, in response to numerous questions about connecting modern stereo devices such as I-pods, MP3 Players, etc., to vintage mono domestic radios, a similar principle to that covered in this thread could be used, the basis of which is two resistors, one from each channel, to combine the LH &RH channels, plus a blocking capacitor in series with the input to the vintage radio. where no 'aux' (i.e. 'Gram') i/p is present, the same approach as used with mono car radios -i.e. disconnecting the lead between the detector and volume control, wiring in the additional components as described. Please be aware, though, that many vintage radios use a Live Chassis technique, and necessary safety precautions must be taken when connecting external sources to these. If in doubt do not attempt this without consulting an experienced engineer.