XXHighEnd

Ultimate Audio Playback => XXHighEnd Support => Topic started by: arvind on December 10, 2012, 08:26:24 am



Title: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: arvind on December 10, 2012, 08:26:24 am
Hi Peter,

Since 3 weeks, I have been noticing that in the first track of the playlist, after about 5 secs, there is a drop in the output volume by over 50% for a fraction of a second. The same tracks played normally earlier.

At first I thought it may be a problem with my preamp, but when I play a CD, this doesnt happen.

Best regards,

Arvind


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: PeterSt on December 10, 2012, 12:10:55 pm
Arvind,

Huh ?

Can you check whether this is related to the SFS ?
Notice that at the first next load of a track part there's an audible tick. It could be related.
Btw, in your X3 log file you can see after how many seconds that 2nd track part loads ("ready to play"). Notice that this is earlier after the 1st part (of any "play" session) than the subsequent next.

Regards,
Peter


PS: If you test with Phase Alignment On, please test it without that and see whether it makes a difference.


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: arvind on December 11, 2012, 02:50:43 pm
Hi Peter,

The X3 log shows this:
1st track ready to play 18:46;51
2nd track ready to play 18:46;52
3rd track ready to play 18:47:02

With PA off the volume does not dip.

Best regards,

Arvind


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: PeterSt on December 11, 2012, 09:22:47 pm
So, a very small SFS. But does a larger SFS get rid of the problem ?
Notice that I referred to the log file so you can concentrate on when it then happens ...

Regards,
Peter


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: arvind on December 16, 2012, 05:31:42 pm
Hi Peter,

This issue is certainly connected with SFS. I increased SFS to 320 & the vol dip now occurs after a min or so.

Best regards,

Arvind


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: PeterSt on December 16, 2012, 06:01:07 pm
Thank you Arvind. But strange !
I will look into this.

What might be important for me ... the title of this topic; Are you saying that this wasn't before 0.9z7-4 ?
(you don't need to check it if you actually don't know).

Regards,
Peter


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: arvind on December 17, 2012, 11:03:02 am
Hi Peter,

It certainly wsnt there before 0.9z-7-4. As a matter of fact it wasnt in 0.9z-7-4 initially. This has started since a few weeks. Thats why I too am puzzled as to what has changed since then.

Best regards,

Arvind


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: PeterSt on December 17, 2012, 11:41:38 am
Hmm ...

As I said (I think), all I know is about this tick at the first "SFS boundary" and since I measure through XXHighEnd itself I should have easily seen this dip, when you can apparently easily hear it.

It is possible for you, somehow, to judge this through another amplifier ? I mean, it almost looks like your amplifier reacts on the DC change. But let's put it differently : do you recognize any changes to your setup (maybe even performed explicitly for Phase Alignment) ?

Watch out : I call this "reacting to DC change" but this can't be it. Or not alone. I mean, that tick at the first SFS is nothing else than some strange jump in output voltage that doesn't change DC. However, that voltage jump itself will be a high transient (max 4V peak-peak to the input of your amplifier) with the duration of 1-3 samples (one sample lasts 1/705600 secs) and now your amp reacts to *that* but including the DC offset blabla ? -> can't be correct when your amp is blocked for DC).

Arvind, this was a brainstorm but it may help you. That is, if you say that this started to happen somewhere in the midst of 0.9z-7-4 there should be some change on your side. And that can also be a XXHE setting of course ...

What I will do now is try to mimic it myself by all means, and let you know.

Peter


PS: What about your preamp ? So, you use one, and it gains (assuming you never changed this). Did you ever check *that* for passing DC ? So, the rule normally is that your main amp shouldn't let in (or pass) DC, but in your case this applies to your preamp, and now your *that* may react to "something" (but in combination with that voltage jump !).


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: PeterSt on December 17, 2012, 04:46:09 pm
Arvind,

If you have After SFS Rounds set to 1, at least *some* things make sense to me ...

?

Peter


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: arvind on December 18, 2012, 07:00:46 am
Hi Peter,

The CAT preamp & amp block DC, I have confirmed it with Ken Stevens. Settings on XXHE havent changed except I used to set SFS=2 & now I am at 60. At SFS=2 I had 7 SFS rounds & at 60 it is 1.

Best regards,

Arvind


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: PeterSt on December 18, 2012, 07:59:37 am
Thank you Arvind, also for your efforts.

Since I now must mimic (or explain !) this behaviour (with high doubts I will be able to), can you tell me how long such a dip lasts ? So, 0.1 second, 0.5 second, 1 second, several seconds, etc. ?

I hope this was my last question. :)
Peter

PS: But another question already : do you have an analogue voltmeter ? (one with a moving needle instead of numbers on a screen)


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: arvind on December 18, 2012, 09:16:14 am
Hi Peter,

I would guess the volume dip lasts for 0.2/0.3 of a second. I can get hold of an analog voltmeter.

Best regards,

Arvind


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: PeterSt on December 18, 2012, 10:44:12 am
A bit ahead of things (but it really is my turn now !), you could get a 50Hz test signal (I can provide that) and see whether the output of the DAC already exhibits the dip. When not, the output of the preamp should. When not, the output of the main amp should. When not, you are dreaming, haha.
But about dreaming : it really can be so that what happens when Phase Alignment engages (because it is about that) this is experienced as a sudden under pressure which theoretically will hold back sound for a brief moment (think like all air is moved away from you towards the speakers). This is where measuring the output (AC btw !) is important, because when that shows nothing while you still perceive the dip, it can only be about this phenomenon.

It might be a bit tricky to interpret all correctly because there's also this tick and this *should* incur for a very short change. But I reckon that this 3 sample dip or peak coming from that won't let move the meter.

But first it is my turn now.
Peter


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: PeterSt on December 19, 2012, 10:35:26 am
Hi Arvind,

No way I can see your dip; Tried everything and all which could be related. So, time for that test signal now ?

If you want to go this route you may need that test signal. Let me know if you want me to email it to you.

Best regards,
Peter


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: arvind on December 19, 2012, 10:52:18 am
Hi Peter,

I think lets wait for 0.9z-8, if this still continues then we can take it further.

Best regards,

Arvind


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: PeterSt on December 19, 2012, 11:24:31 am
I don't foresee a change there, but of course it is so that I am looking through the due 0.9z-8 ...

Peter


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: arvind on December 24, 2012, 10:26:23 am
Hi Peter,

Strangely enough the problem seems to have solved on its own, just like the way it suddenly started. Who says computers are not tempremental.

Merry Christmas to you & your family.

Best regards,

Arvind


Title: Re: 0,9z-7-4/0.9z-7-5 problem of drop in volume in first track
Post by: PeterSt on December 24, 2012, 12:11:51 pm
:scratching:
:)