wiring of the output jacks

[mazatta]

I have constructed my core and OPL3 modules (with 2x512 chips) and would like to test the audio but I don't think I am understanding the output jack wiring properly (mbhp_opl3_interconnections.pdf), as I don't get anything out of the one jack I have wired up so far. I am using mono jacks, but I assume that is what should be used.

Does pin 1 of J4 for instance connect to the tip of the first output jack and then the ring of that jack connects to the ground of J3? I don't have mine like that currently but that's the only other way that makes sense to my noob brain right now.

Any input is appreciated, and hopefully this will push me to learn the ins and outs of these jacks :)

[rosch]

J4-J7 each have an output pin (Ox) and Ground (Vs). you could wire each jack separately (O to tip, Vs to the ground ring) but here it's recommended in the pdf to connect all the grounds together and wire them to one point where they meet the grounds of the core and the opl3 module (in order to avoid ground loops= humming). the output pins still have to be connected to the tips of the corresponding output jacks using separate wires.

[sparx]

That is how I understood it to be as well.

I'm trying to finish mine and just wonder why the audio is routed to two stereo outputs instead of just the one?

No real problem, just wondering.

Regards

S

[Janis1279]

That is how I understood it to be as well.

I'm trying to finish mine and just wonder why the audio is routed to two stereo outputs instead of just the one?

No real problem, just wondering.

Regards

S

In a photo in the OPL3 article you can see four stereo sockets for the opl3 board audio outs, but in reality it is quite enough with the four mono sockets :

http://ucapps.de/mbh...connections.pdf

Regards, Janis

[sparx]

In a photo in the OPL3 article you can see four stereo sockets for the opl3 board audio outs, but in reality it is quite enough with the four mono sockets :

http://ucapps.de/mbh...connections.pdf

Regards, Janis

Yes, I can see that, thanks, the question was why two stereo pairs instead of one?

S

[Janis1279]

More outs, more fun:

from the OPL3 article:

" The DAC outputs are directly connected to the YAC512. Sound cards are mostly stuffed with only one YMF/YAC pair (I've never seen a card with two YAC512) which results to 2 audio channels. With an additional YAC512 four separate channels are available, which is especially useful if the outputs should be routed through different external effects."

[mazatta]

I have connected the output pins to the tip all of my jacks (just had one hooked up before) and tied the sleeves in with the core's ground and still nothing. I have also tried re-uploading the test tone app and reworking the solder joints on the 512s and the OPL3. Voltages all look good going in to the OPL3 module (+5v @ J2 and +12/0/-12v @ J3).

I imagine it is time to start playing with the interconnections test?

[sparx]

Check all slder joints, recheck the wiring, load the testone app, it makes troublshooting a lot easier.

More outs, more fun

Guess I asked for that... :yes: