Sound board query

[robm]

I am trying to make a line out  for my Black Rose to run a set of powered computer speakers to see how they go.  From pinrepair

Line-Out.
The pre-DCS A-12738 has "line out", through connector J509. This is a tap into the mixed analog signal (from all three sound generating devices) before it going to the volume control and final output amplifier circuits. Connector J509 pin 1 is the Analog ground, and J509 pin 3 is the Analog sound out.

Unfortunately a bit more needs to be done then just tapping into connector J509 to get a usable "line out". On pre-DCS games on the component side of the sound board, lift resistor R102 on the side which connects to pin 3 of J509. On the back of the sound board, connect a jumper wire between the negative side of capacitor C21 and the plated-thru hole left of resistor R102 (which connects to pin 1 of J509). This will give a functional line-out at J509 with the pins indicated above. The line-out you get from this modification is a fixed level and does not get changed by the volume control.

I'm a little confused - does this say to;

1. Lift up one end (that connects to pin 3 of J509) of R102 and leave it hanging in mid air? (would this be in case you want to put it back to original?)
2. Jump  -ve side of C21 to ground (pin1 of J509) - i can't see any plated through hole left of R102 he is referring to.

Has anyone done this before?

Thanks

[Marty Machine]

A little confusing, i agree.

I have the manual but it doesnt have a detailed schematic of the Audio board, so i can't offer an alternative mod.

I'm confused why he states J509 is line out, but you need to mod it to make it line out? what the ????

MM

[robm]

I ended up grabbing a $2.50 3.5mm audio jack from jaycar and used the cabinet speaker wires to it, then plugged the external computer speakers in.

Works a treat and sound quality is increased very dramatically (particularly since there is a small sub with the computer speakers)

[shansta]

So - your using the speaker outputs to drive the line in of the computer speakers? (assuming they are amplified?)

[Marty Machine]

I think your computer speakers are simply 'speakers' and not amplified/line in etc, otherwise your PC speakers would be VERY distorted.

Feeding a speaker output (several VOLTS) into a line-in socket (100-200 MILLI volts) would be a big no-no.

MM.

[robm]

Yes - i am using the speaker outputs to drive the line in of the computer speakers.

I always assumed they would be amplified (being powered), they are Logitech X-230 speakers, but i also thought they would distort - but it is not the case.

 

[ddstoys]

You can buy a Speaker out put to RCA converter which will bring your speaker output back to Line level which would be a lot safer.  Check out auto barn and places like that

[shansta]

Yes - i am using the speaker outputs to drive the line in of the computer speakers.

I always assumed they would be amplified (being powered), they are Logitech X-230 speakers, but i also thought they would distort - but it is not the case.

Fair enough, I asked for the reasons Marty has already outlined... If it's stupid and it works - it isn't very stupid is it? :)