Slightly OT: stereo and mono audio splitting

[InTheSand]

Hi,

This is slightly off-topic, but I'll ask here anyway since you lot are knowledgeable in the ways of electronics!

What I want to do is to split the audio and video output of an A1200, with one part going to a 1084S, and the other to an RF modulator for feeding into a distribution system.

The video part is no problem - the 1084S can run from the A1200's RGB video output, and the modulator can take the signal from the colour composite video output.

However, for the audio section, the RF modulator only has a mono audio input. I wish to split the Amiga's stereo into two parts, so that the 1084S still gets a stereo input, and the RF modulator gets a combined mono.

Obviously, a simple stereo Y-splitter plus combiner isn't going to achieve what I want, as the 1084S would then get a mono audio signal.

Is there something cheap to buy and/or simple to build that will let me split the Amiga's stereo signal into two outputs, each isolated from the other so that one of them can be combined into a mono output without affecting anything else?

Thanks in advance!

 - Ali

[InTheSand]

Hi,

Thanks for your comments, and good points re: the internal modulator, but I want to feed the signal from the Amiga into an existing distribution system, so an external modulator (with an RF input as well as output) is necessary.

I have basically got the following:

Roof aerial --> modulator --> distribution system to several rooms

So effectively, the Amiga appears as a TV channel alongside the standard TV channels received via the aerial (no, NZ doesn't yet have digital terrestrial!)

I'm just after something small that will electrically separate two stereo signals from a single line level stereo output.

 - Ali

[InTheSand]

Hi,

Thanks for the replies!

Firstly, @Kronos: yes, NZ does have TV, and in colour too!!! :-) Broadcast in VHF and UHF - and the VHF suffers horribly from weather-based interference, which I guess is why every other country stopped using it in the 1980s!!!

I was thinking that something along the lines of Tenacious's suggestion using op-amps of some sort (though I'd need a pre-made circuit diagram!) and didn't realise that a couple of resistors would do the job (thanks Hodgkinson)! I'll have to give that a go.

Cheers,

 - Ali

[InTheSand]

Hi,

Re: music shops - Nelson, where I live, is only a small-ish place and doesn't really have much in the way of specialist shops. The local electronics shop (Dick Smith, a bit like Maplin and/or Radio Shack) couldn't recommend anything, and I'm a bit reluctant to spend loads of $$$ on something either online or hours away in Christchurch (nearest larger city).

I'll definitely have a go with the resistor idea, otherwise it'll be something I can build with op-amps.

 - Ali

[InTheSand]

Hi Anthony,

How's it going?

Thanks for your reply. I was aiming to create something that could be used for other audio sources, so would rather avoid the use of any Amiga-specifics. At some point, I'd like to make a similar thing for a network-based media player (which has composite out, s-video out and stereo audio) so that I can feed that into my distribution system too.

I guess a couple of variable resistors on some breadboard might be the way to go, to allow me to test and tweak before I solder anything.

As for the modulator - it came with a single sheet detailing how to set its output channel and not much else, so I've no idea on its input specs... I brought it over from the UK.

 - Ali

[InTheSand]

Hi,

The A3K is going well, thanks! I re-seated all the ICs as you suggested a while back, and also upgraded the Buster and WD SCSI chips to the latest revisions. No real problems since then (aside from the occasional non-detection of either the graphics card or the Catweasel/Buddha, which is cured usually by a power cycle), so it's going well.

Back on topic, a mixer at the $30 area would be great - a shame DSE has stopped selling it. I'll keep a lookout on TradeMe (am on there lots anyway!) for something second-hand, but eBay is a last resort! Never had any problems with eBay when I was in the UK, but TradeMe is so much friendlier.

 - Ali