Amy,

Here is where you still have some misunderstanding:

"he keyboard plays the midi signal the first time --> goes to the cpu --> can get changed by software (ie- asking the computer to change the sound to another instrument) and then --> back to the keyboard midi in ...thru the keyboard --> out the keyboard. Because MIDI is so compressed and fast, this happens almost completely instantaneously."

MIDI is not audio data. Period. All that it consists of is commands, when and how someone pushed buttons on some midi device, how fast they pushed, perhaps how hard and for how long. Commands. Like in a Word document, a record of what letters were pushed, but not the actual font details - which are stored outside of Word.

The CPU and Word combine the details about which letters were typed, which font was used, and combine them together to shoot to the screen - where you see what appears to be a simple document - the analog output of the combination of letters and fonts. You can make an analog hard-copy on the printer.

The computer CPU in the music sense - this is where the sound conversion from digital to analog will happen if you are using the computer as the sound source. The analog data DOES NOT travel with MIDI back to the keyboard. All that the keyboard can do, specifically this PX-130 is the following:

1. Output analog of one of the 16 types of sounds through it's jack; which in this case is a TRS jack for either headphones or to split out to L/R (which will be fine - just take Mac's advice)

2. It can connect to a computer that interprets MIDI commands over USB, then the computer is used as the sound source. Here it is a special kind of controller keyboard. Many controller keyboards also include the physical MIDI in/out jacks (and a few still have thru- but that's less common these days).

3. It MAY (and I use that cautiously) be able to control sounds for a box like the Muse Receptor/MuseBox - but don't take my word for it - those boxes would need to be able to interpret MIDI over USB, which they may not. They are really PCs with audio interfaces built in and a specialized Linux OS to do just this one thing.

That is all. There's no way to make analog audio or even digital audio travel over MIDI. So, your idea to send audio back to the stage over MIDI - sorry, that is not how it works.

MIDI is actually a serial data bus carrying only 'event' type information, no audio. Nada. Zilch. etc.

Even with the digital snake scenario I described above, the only sounds that will ever come out of the Privia PX 130 are the built in sounds. That's it. Some of the higher end Privias have great sound sets. This one is designed to be very basic. That said, for piano and electric piano, it's probably great.

My advice would be: DO NOT go towards Reason, Reaper, etc. until you have a little better understanding of what is at play with how midi works, how sound synthesis works inside a keyboard, inside a PC, etc. I merely mentioned the use of Reason by the Brian Davis band because it's a clever way for them to keep their 'show' organized and sounding full, with mostly live players (sans a keyboard player), etc.

What again is the main goal for the church? Are you trying to play accompaniment tracks live? If so, then you can do this from the back of the church without much issue. You just need a way to trigger the songs from the stage or with a helper at the FOH mixer.

Don't toss that Privia yet. I think your fear of going from 1/8 inch to XLR is that you are worried of doing this all on the jack itself. Do this: 1/8th stereo to 2x 1/4", then plug those 1/4" into either a stereo direct box to XLR, or 2 different direct boxes. You will be fine this way. You could even stand to do a little 1/8" stereo splitter out of the headphone jack on the Privia - take one to some headphones, and the other with the cable combo listed immediately above - to give you ability to monitor what's coming out of the Privia.

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