Re: XY as Audio

Hmm the problem would be the same as is currently happening, except you
would probably blow up your speakers if the outputs are bad...
The idea here is to run the XY amps unloaded so as the output
transistors don't croak if the drive is bad. Perhaps a resistor, say 100
ohms might be enough of a load to test. I'm trying to find a simple way
to power the monitors (I have about six or so) without having to have a
running game board, nor do I want to toast the outputs by having hte
yokes connected. Soon this will be happening. Is anyone interested in
tested working 19" XY's? Somewhere around $250-$300US... May have my HV
hack...

Am also chatting with a TV parts wholeseller about flybacks, and we are
looking for a cheap flyback that puts out the voltages needed, and just
hardwire the !@!%$!% thing into a chassis. Then adjust the frequency
down to the 15,XXX (can't remember XXX) Hz so the flyback is happy. This
is not much different than my hack, but might be tidier if it can be
installed in the regular HV cage. Anyone have some time that wants to
look into this with me? That lives near Vancouver? That can handle a
soldering iron????

John :-#)#

jwelser@ccwf.cc.utexas.edu wrote:
>
> Dumb question, and someone might've suggested this already
> (I haven't been following this too closely) but why not, instead
> of coming up with an audio signal to create some predictable video
> signal, why not just use the deflection board/monitor chassis as
> an audio amp (which is essentially what it is) and listen to the
> outputs. If it's working properly, you should get out what you
> put in, and you should be able to recognize it.
>
> The only trick is getting the right level for the input,
> and then you'd need some sort of differential to single-ended
> converter, because most speakers want single-ended inputs, while
> the outputs to the yoke are differential. I can see some board
> that plugs into the output to the yoke, which just has a diff ->
> single ended converter (a couple of op-amps and resistors -- our
> apps. guys put them on our eval. boards all the time at Crystal..
> errr, I mean Cirrus Logic -- Austin :) ) and a speaker. It should
> actually be pretty easy, and should work -- unless I'm missing
> something.
>
> Of course, it doesn't test the HV, neck board, etc, but
> it might be a real nice way to test deflection boards/chassis.
>
> Joe

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