Doubling up on inputs


New member
Aug 10, 2019
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Hi all,

thought I'd come and test some hi-fi knowledge as I'm not all that clued up!

I've got myself a little one input amp (Muse EX2) and am very happy with it - does a good job with my ipod and some old B&W Dm110s which was the only thing i had hooked up. I've just come into possession of a KAM BDX 280 deck so would like to hook that up.

So, ideally I'd be able to have the ipod and the deck both plugged in at once. I bought one of these

which I hoped would do the job - not a pro-audio cable or anything like that but that's not what I'm after. Standard no frills cables like this are fine for my needs.

The problem - the cable seems unbelievably noisy. When plugged in like this:

Deck------------>pre-amp------------>amp with the stacker between pre-amp and amp, it is very noisy, huge humming sounds and distorted playback of records. If I then plug the ipod into the stacker so both sources are plugged in, the noise is overwhelming, more or less louder than the music.

Likewise, if I take the cable from the ipod to the amp and leave the deck out, I still get a nasty, loud humming.

It's not the deck or pre-amp - when plugged in with a standard cheapo rca-rca it sounds fine.

So..... is it a bad cable (my first thought)? Or.... is this kind of cable always a bad idea for what I want to do and I should just make do with fiddling about around the back of the TV unit when I want to change inputs? Basically, should I go back to the complany that sold me the cable and complain or just accept that this kind of cable is not going to do what I want?




New member
Jun 10, 2011
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Two things...

Firstly you can not just "parallel" source components like this. It's a big no no, whether they are both on or not. The technical reason is that line output stages are really small amplifiers with fairly low impedance output and you just never do this.

It would be like connecting two amplifiers to one speaker.

That said if it is humming with just one item connected or just the leads even and your old lead is OK then that sounds like a duff lead in some way.


Thanks for the quick replies guys - I had a nagging fear that I was being a bit of an idiot somewhere here and it's been proved to be so!

Looks like one of those audio selector switches is the way to go then, thanks for the links, much appreciated.


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