I don't have one of these (just the earlier 2-channel version), but looking at the online manual, it needs powered speakers, e.g. there is only line-out levels on the out 1& 2 - also the out 2 is to be used for headphones, which may imply a different drive capability on the two outputs.

https://www.dosdays.co.uk/media/diamond/Monst … X300_Manual.pdf

Rwolf wrote on 2024-11-27, 14:48:

I don't have one of these (just the earlier 2-channel version), but looking at the online manual, it needs powered speakers, e.g. there is only line-out levels on the out 1& 2 - also the out 2 is to be used for headphones, which may imply a different drive capability on the two outputs.

https://www.dosdays.co.uk/media/diamond/Monst … X300_Manual.pdf

I looked at the manual before, trying to make sense of things.. but only vague details on page #19 :
* Use Out1 with 2 speakers
* Use Out1 and Out2 with 4 speakers
Attach your headphones to Out2 only. (not at all explaining why, or why not on Out1)

But indeed, it might be because it has some small amplification circuit on Out2 (which the member @appiah4 seems to confirm here: Diamond MX300 (Aureal Vortex 2) software wavetable crackling/clipping)

Question is: shouldn't this circuit, normally be disabled when not using Out2 as "headphones mode" in the DIAMOND control panel?
Because, otherwise, for "Stereo X2" or "Quad mode" you'll just have the back speakers at a louder volume, messing up the whole surround experience..

Yes, I would expect the Out2 to be set at low line-out levels when not in headphones mode.
Maybe someone here still has this card and can figure it out.

No one else has experience with this card? 😕

one way to test this, you can connect a powered speaker to the card and compare the output level of each output. If the speaker sound the same then all is good. otherwise, your card may have some defect.
I did have the card in the past along with the mx200/mx400, but i sold them long ago and i regret that decision till today 😁

nhattu1986 wrote on 2024-11-30, 04:58:

one way to test this, you can connect a powered speaker to the card and compare the output level of each output. If the speaker sound the same then all is good. otherwise, your card may have some defect.
I did have the card in the past along with the mx200/mx400, but i sold them long ago and i regret that decision till today 😁

This is good advice, yes.
But besides simultaneously connecting two pairs of @30-Ohm headphones (one on each output), which exposed the difference in volume, no matter which way I plugged them; I then, also connected my 5.1 audio system (which I presume is 8-Ohm). But unfortunately because of the position and distance between the satellite speakers , I couldn't quite make out if there was any volume difference between front and rear.

Will try again soon with 2 pairs of desktop speakers, side by side... but... I would be extremely surprised if both outputs would suddenly sound equal, just because of the speakers' lower impedance.. 😯

So, I couldn't get my hands on two identical sets of speakers, so I tried again with the 5.1 system, bringing in a second person to listen closely to each speaker.
Results seem to be that there's little to no difference with (these) powered speakers.

Still.. It would be VERY nice to get a confirmation from someone that has this card; that indeed there's a difference between OUT-1 & OUT-2 volumes, when the card is in "Quad mode" or "Stereo x2" with headphones connected to both outputs.