ux-3 wrote on 2024-05-18, 10:30:

I have a TT Gold 16/96 which is working normally, as far as I can tell. Except for one problem:
I don't get any sound on the line out plug. None.

Most sound cards are designed in a way that the line out signal is used as input for the speaker/headphone amplifier. So getting a good speaker signal indicates that the output path of the sound card is basically working. Looking at the high-res picture of a TT Gold 16/96 at http://www.amoretro.de/2013/01/terratec-1696- … soundkarte.html , it seems the components used to provide the line-out signal to the jack are R32/R33, C51/C52 and L3/L4. If one of those components were bad, it would only kill one channel, so I also cast some suspicion on the line-out jack PJ2 itself. It seems like the line-out signal should be present on the 4-pin jumper header J2 as well as on JP2. Installing jumpers on J2 is likely to short the line out jack and could explain a completely silent line-out jack. To confirm that the jack is working, I suggest you connect a cable to the line-out jack and test continuity between the other end of that cable and the pins at J2.

No jumpers there.
I just used a slim plug cable and a multimeter.
I can verify the connection of that plug to the 4-pin header. The plug's two tips connect to the outside pins, the plug base connects to the two central pins.
Same pattern as on the next 4-pin.
The problem is most likely elsewhere.

Found it!
As the cable I used was obviously working in the plug, I used it to connect to a mobile speaker. And yes, it worked.
The headphone plug is slightly shorter... it works in the other plug though...

Thanks for helping

Not sure why... Used a y-adapter. One to the speaker, one to the headphone. Headphone gives NO sound.
Baffles me...
Solve one puzzle, win two new ones.

ux-3 wrote on 2024-05-18, 14:15:

As the cable I used was obviously working in the plug, I used it to connect to a mobile speaker. And yes, it worked.
The headphone plug is slightly shorter... it works in the other plug though...

If I am correctly suspecting that the resistors R32/R33 are on the way from the line-level signal on the sound card to the line-out jack, they provide that much attenuation that a headphone connected to the line-out port is basically silent. The impedance of a typical consumer headphone is around 32 Ohms. The resistors R32/R33 are 47.000 Ohms. This creates an voltage divider that reduces the voltage at the headphones to around 1/1000 of the level on the card. As power is determined by voltage times current, and reducing the voltage to 1/1000, you also reduce the current to 1/1000, the electrical power to the line-out jack is reduced to a one over a million if you connect a low-impedance device like headphones or (even worse) passive speakers.

The line-out is only meant for active speakers with their own amplifier. These speakers do not rely on being powered through the line-out jack, so they don't try to pull a lot of current from the line-out jack. Because of that, the signal is not reduced that much. A typical input impedance of devices with a line-level input is between 50.000 and 100.000 ohms, so the resistors only reduce the voltage to 50% of what's on the sound card, and this might actually be intended behaviour.

As not every sound card has resistors that high on the line-out jack, you might have better experience with headphones at the line-out jack on other sound cards, but this is not an intended use of the jack, and may fail depending on the sound card design.

Makes sense. No other old card of mine works like this. Many thanks.

But while the regular output of the TT Gold is rather noisy, this one is really quiet.
My other card with the same ESS chip is noisy no matter if jumpered for amplification or not.