XXHighEnd

Ultimate Audio Playback => XXHighEnd Support => Topic started by: Chris V on February 19, 2008, 09:28:16 am



Title: Does 0.9u have gain
Post by: Chris V on February 19, 2008, 09:28:16 am
Hi Peter

Having read your installation instructions for 0.9u it seems a bit scary.

Have I missed something or is 0.9u adding gain in the PC?

Cheers Chris


Title: Re: Does 0.9u have gain
Post by: PeterSt on February 19, 2008, 10:20:32 am
Hi Chris,

No, no gain is added. Let me guess why you ask ...

When I talk (in the Relase Notes) about dangerous levels of crackling (I didn't say it like that exactly, but is is what I mean), this is about something going really wrong to the matter of "calculations" and how much byte values should be. Let's say that the DAC can "clip" which really is about jumping the max voltage output it can have (say, 2V) from +2V to -2V in one go. This is too steep to follow for the output stage and it causes the "static" crack. This is so loud, that even with the pre-amp connected and its smallest volume setting possible, it can be rather loud. Not that the windows go out, but it has such transients that you'll drop from your chair. :)

Remember, this is about trying to get things to work in numerous different DACs, and while it's kind of guessing for me how they should be fed in certain situations, there's also the combination with Vista Exclusive Mode which is kind of wacky. I mean, it might report to the program that something is possible, while it actually is not. Thus, e.g. when it says that 32 bits should be fed per sample while actually it is 24, I'll be feeding with (remapped) 32 bit voltage values, while it really should be 24. And, in dB this is just 48dB too much. So, your music may be normally playing, but peaks (and all) are fed 48dB too high, and all will be cut at the +2V/-2V level, and each other sample may imply those voltage jumps.

In the end, so far, I did not hear anyone having such an experience (or they ar ein hospital now :)) so I think this is not a problem. I had it myself many times though, just because of doing things wrongly. As a matter of fact the next coming hours will again be party time here, because of testing upsampling to 88.2/24 (so far this was 88.2/16).

Quite another reason would be that you make a mistake in the setup. So, follow the procedure as described in the Release Notes and you're ok, but still you must be careful to indeed follow that procedure. For example, if you forget to set the XX volume level to a reasonable level (while at first you don't even know what that is ! so you could set it too high), then the windows may go out even with normally playing music. It depends on the gain of your amps and the sensitivity of the loudspeakers. For example, a while ago I played with the 115dB sensitive speakers with 4x 140W RMS amps. Now *that* would be bad if it came out unattennuated ... Mind you, the 4x 33W I have now already would near self-launch the speakers. :yes:


Is this what you wanted to know ?
Anyway Chris, don't be afraid and just try it, following the procedure. I think you won't be sorry in the end.