[Aren Yashar]

Ok, here's the problem. I am attempting my own take on a NES PC (Casemodding a mini-ITX motherboard into a front-loading NES). The output jack for the audio is (of course) the standard 3.5 mm stereo telephone plug. I already know the pinout for the plug, that is a non-issue.

But the issue is this: I want to retask the sliding switch on the back of the NES (keeping all the external connections vintage, even if they are being repurposed to some degree) from selecting channel 3-4 for RF output to switching from the traditional mono output the NES is noted for and stereo out (utilizing the white RCA jack for the added channel).

I figure I can tie pin R (the intermediate 'sleeve') directly to the signal pin of the red RCA jack, soldering it in place. But for pin L (the tip of the plug), I was thinking of hooking to that switch. Channel '4' would be stereo mode, shooting the signal right to the white signal pin.

But the question is this: What do I do with channel '3' in order to make the red RCA port a true mono-out? I have done some reading, both on these forums and on the net in general, and I have come across a few solutions, but they seem a bit sub-optimal...and I thought if I posted my solutions here someone could point me definitively at one of them and tell me why it's the best choice, or suggest something that a night's research into this hasn'tturned up for me.

Solution 1 - Take the lead from 'channel 3' and short it directly to the red signal lead, melding it there (with all the inherent problems of potentially damaging the red RCA input jack on the TV(s) I will be hooking my new PC into for gaming/internet use.)

Solution 2 - Slap a 10 K resistor at the front end of both raw lines, reducing the overall signal output (resulting in a quieter computer, and allowing safe signal integration when the set is switched into mono mode)

Solution 3 - Leave the lead from 'channel 3' hanging, or short it to ground, thus cutting that channel completely from the circuit in mono mode, resulting in a faux mono signal (half-stereo).

Solution 4 - Don't hook up the switch in the circuit at all and just tie pin R directly to the white RCA signal out, and forget about being fancy with my new project. (Which needless to say is a simple cop-out and one I would hesitate to do unless completely necessary. I know I could retask the switch to something else, but it seems fitting to have it perform the audio stereo/mono function given it's location on the case...right next to that white RCA plug.)

Please keep your explanations as simple as possible, while I know a good deal about computers I am lacking in electronics experience. That is one reason I'm doing this project, to expand my horizons and learn something that could potentially be useful to me later in life. Thank you.

- Aren Yashar

[Aren Yashar]

Doing more research into this, I've come across some more terminology that might help. Specifically, would the rated power of a normal TV speaker be able to accept the 'forced' mono output of a standard issue mobo-based sound card? Both the Left and Right channels fused together without resistors on the line which would make the design less feasible for what I'm attempting to do?

Quote from wikipedia:
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Rated Power – Nominal (or even continuous) power, and peak (or maximum short-term) power a loudspeaker can handle (i.e., maximum input power before destroying the loudspeaker. It is never the sound output the loudspeaker produces). A driver may be damaged at much less than its rated power if driven past its mechanical limits at lower frequencies (e.g., by bass heavy electronica or theatre organ music). Tweeters can also be damaged by amplifier clipping (lots of high frequency energy in such cases) or by music, or sine wave input at high frequencies. Each of these situations pass more energy to a tweeter than it can survive without damage.
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[Aren Yashar]

bump

[Aren Yashar]

bump

[Aren Yashar]

bump

[prunejuice]

No offence...and I love your idea of an NES PC...but maybe you could get more feedback on a more modding orientated message board...

Like this:

http://forums.benheck.com/