Nice!

What kind of cable are you using to connect the Sound Blaster with your receiver?

Digital optical vs coax there should be no difference, it's just a stream of 1s and 0s.

I'm using a "temporary" rca just to test if it's worth to go further ! I've seen that I lost the digital output that I might use in games or demos, but the cd-in and waveblaster, I couldnt care less for them lost. I'm surprised and happy to see that the opl3 of the ct2670 is routed on that spdif pin. I cannot understand it but I'm not complaining at all.

Remain to have some info about the pcm data format and to see if it's possible to do it with a gus classic.

PhilsComputerLab wrote:

Nice!

What kind of cable are you using to connect the Sound Blaster with your receiver?

Digital optical vs coax there should be no difference, it's just a stream of 1s and 0s.

Correct, TOSLINK will give no benefit (except avoiding signal level conversions). I usually use composite video cable for SPDIF, although impedance will not be so critical for short runs.

ElBrunzy wrote:

I'm using a "temporary" rca just to test if it's worth to go further ! I've seen that I lost the digital output that I might use in games or demos, but the cd-in and waveblaster, I couldnt care less for them lost.

So just a cable from the header to the receiver? No active components in between?

PhilsComputerLab wrote:

ElBrunzy wrote:

I'm using a "temporary" rca just to test if it's worth to go further ! I've seen that I lost the digital output that I might use in games or demos, but the cd-in and waveblaster, I couldnt care less for them lost.

So just a cable from the header to the receiver? No active components in between?

Almost certainly TTL level SPDIF. Both of my receivers decode that properly, but YMMV. If required, you can level convert with a resistor divider and a coupling capacitor. That, or use a TOSLINK transmitter.

ElBrunzy wrote:

[*]Can such a "hack" be done on the gus classic ?
[*]I read that the cd-in and waveblaster are disabled on the spdif, does the ct-1747 is disabled too?
[*]Does people have any information about the audio format of the spdif ? All my receiver do is fallback to pcm when I try to switch it to ac-3, so I guess it's pcm 44.1 stereo, right?[/list]

Perhaps an SPDIF output could be generated on the GUS, but almost certainly not this easily.

The EMU8k outputs SPDIF directly which makes this mod easy. The CT-1747 usually outputs FM through the EMU8k for chorus and reverb. That's why FM works. Unfortunately, analog input sources don't get the same treatment.

Output should be 2 channel PCM at 44.1khz. I'm not aware of any toggle or option to allow SPDIF passthrough, so I suspect AC3 and DTS are out of the question.

gdjacobs wrote:

The EMU8k outputs SPDIF directly which makes this mod easy. The CT-1747 usually outputs FM through the EMU8k for chorus and reverb. That's why FM works. Unfortunately, analog input sources don't get the same treatment.

Interesting choice to have decided that the opl3 could benefit from the Rvb/Chor of the emu8k but nothing else, like the digital voice. How is the opl3 mixed with the emu8k before the spdif ?

I've did an spdif.cfg and dac.cfg and switch before calling mixerset /p to change from when the receiver amplify analog or digital signal of the card. On digital, muting and disabling everything but the master and midi. The bass/treble and the output gain are all useless and defeated. You know how dynamic some .mid or .mod are, it's breathtaking to listen to them at high volume with such sound clarity and definition 😵

Some good info on EMU8000 signal routing in this thread:
Non working AWE32 CT3900.

*moved to marvin*