USB Clock Upgrade My Experiences (so far)

[Scroobius]

OK so my better half has just been listening to Dexa versus not Dexa AND she insisted from the start that I must not tell her which NOS1 she was listening to (Dexa'd or standard). Sensible girl so "single blind" I tried to keep a poker face to not give any hints as to which was which.

So we started with "NOS A" and played the first track (Elvis Costello Wise Up Ghost - hard processed recording) and then I changed to "NOS B" and played the same again. OK mmm where is that "embarrassed" emoticon she said "have you turned the volume up?" to which I replied "no". She said "well it sounds louder, fuller, more out in the room, clearer, more detail, I can hear the emotion in the voice better I prefer this one" - the first one [NOS A] sounded flatter more recessed less clear not so engaging".

We tried the same comparison on a number of different tracks different types of music and every time she easily spotted which NOS was which and every time she preferred the Dexa'd version with similar comments to above.

But then we listened to Eldar - good quality jazz recording on NOS A - with this much better quality recording immediately she said "this is your NOS the blue one" so I said "well you ought to hear the other NOS before you make up your mind". So I changed to NOS B and she said straight away "no I got it wrong this is your NOS" - well maybe not very scientific that last "blind" test but anyway.

That is pretty much verbatim - anyway she 100% knew whether she was listening to Dexa or none Dexa - and preferred Dexa.

But that does not mean Dexa is more accurate of course but that is what happened.

By the way maybe when Ros said "louder" maybe I would say "dynamic" well anyway now you know maybe I was wrong!!

Oh by the way for quick comparison / switch over I left the PC end connected the DEXA'd pcie card - which does sound better than when connected to a none Dexa'd pcie card. So a bigger difference could have been heard with standard USB3 none Dexa'd card.

Cheers

Paul



 

[Nick]

Paul,

I think Ros deserves a medal for being so patient and I have to say I think she has "first class hearing" as she spotted the extra "good" loudness of the dexa setup   

Really though, very interesting and I hope you are both enjoying the sound.

Kind regards,

Nick. 

[acg]

Thanks for sharing Paul and very interesting stuff.  I am still kind of glad that my wife regards this audio stuff as a folly.

One thing to possibly do is to measure the SPL between the two dacs which would get out of the way if one was in fact louder than the other.  I am with you that more dynamic can fool us into thinking it is louder, so it would be nice to know what you measure.

Cheers,

Anthony

[acg]

Also remember that louder music often seems better...level matching is very important when doing critical listening, so if one is actually louder it may explain at least some of Ros' impressions.

[PeterSt]

Hey,

The below is worth nothing, because it is just about that "random" setup of mine and though I express about it heavily I feel it is off topic. Anyway, this is what was going on here yesterday :

With our both reference of the day before and the eventual expression by Ciska "isn't that a tad on the hasrh side" with my response "no, it is way loud", yesterday it took seconds only to make her say "too loud !". But it wasn't at all (80 maybe) and I didn't change (this is dangerous as we know). A next album was harsh according to her, but I did not hear that. But changed the album (hey, these days we can use Madonna only as test object).
Again I was thrown at with a "tirering" (like the day before).

It puzzled me; I could see where the remarks came from, but to me to doesn't work out like that.
I put on one of her favorites (a Jimmy Smith) and thus well known, and AGAIN it was harsh.
Btw, we use the term "sharp" when literally translated, but it can't be literally translated; my mentioned harsh would be in between English harsh and sharp.

So what in the world could be harsh while I only hear detail in a new way. Is it this "new way" ?
Then in the first track of Jimmy I heard tambourines. Ah, shoot, I wanted to tell you about that yesterday as THE example of on/off separation. Ok, in between the lines :

What comes so much forward is how the individual bells of tambourines are so auudible. And, I think we all know about this in the first place; can be a grey-ish sounding instruments which shows a flat one-graduate hit on the hand, or when the system improves the color comes more in and you start to hear separate bells (okay, tiny little cymbals).
So, this occurred to me the first nightm and that from synths (yea, sorry).

Back to Jimmy. So, I noticed tambourines I never ever even heard. Don't ask me what I heard instead (the sound itself can't be missed), but the guys use tambourines suddenly. Ehm, all over actually.
And so I pointed that out like "hey, I don't know what's up with you or possibly me, but did you notice these tambourines now ?" ... and this with a tone of "you better think this is better because it has to be". LOL

But crucial side note :
It never happened before that we had so much disagreement. Actually we never have.

One of the things coming from this was her "so boy, then let me hear S'es". Yup, this is always crucial because when S'es don't work out (like not at all or hurting) something is wrong in the base for dead sure. Anyway here too, it went with a tone like "for sure they don't work, because otherwise I wouldn't have problems somewhere".

But they worked and they worked perfectly.

I noticed another thing yesterday;
One of the measures is always applause. This so easily fails. However, we (or at least I) tend to judge this two ways only : Or it is to sharp and therefore something is wrong (hey, now I use the literal sharp !) or it is not and no matter it could be blanketed no real more measure points exist; It is too difficult (perceivedbly because no recording engineer tried to capture the audience clapping for the best anyway BUT when too sharp it should be wrong anyway).
Yesterday for the very first time I heard "sharp" clapping as my own hand clapping would be and it was NOT too sharp. So, in all the by now 1000s of test hours for the first time I found a next (third) gradation in how applause can sound.
Should tell something.

All I can tell is that the perceived harshness/sharpness is at a totally different "frequency" level. I *was* able to point out how much natural a hit on a snare drum suddenly sounds and how it does exactly NOT comes along with a too transient hit (think again about the one transient now being "unfilled" with small gaps of on/off). I was able to point out that S'es even perceive a tiny "vibration" (not the zzzoom type) which CREATES the S, instead of hearing an S which is just there and can easily go wrong.
Hmm, I see myself writing this CREATES and may have found a key there.

Ok, as said in the beginning, never mind much. But here too we have our little fights sometimes about who is right and who must be wrong, but this one is strange and not sorted out yet. The sound is totally unsusual, that is right ...

Peter

[Scroobius]

Hey Anthony - I just ordered an SPL meter well I needed one anyway!

Paul

[PeterSt]

LOL

Yeah, and what do we use that for ??

"Hey, see, this IS not loud. Don't nag now !"

[acg]

Hey Anthony - I just ordered an SPL meter well I needed one anyway!

Paul

You could use your phone or iPad as an interim measure Paul.

Peter, what are your next steps?  Are you tempted by a clock change?

Anthony

[PeterSt]

Anthony, no. Not at all.
Or yes when it is actually about the "trimming" hence my situation is purely coincidental and I have it trimmed right.
Notice the possibility for "trimming" needs other oscillators anyway.

But honestly someone should get the "one clock" to run first; this will be a so much different situation that it will be too important to just lay aside. I wanted to do this through special means, but I can't get the basics of that running (while it just should so that makes me wild). Also : I really need to do other things at this moment - like finishing some XXHighEnd version ...

Peter

[PeterSt]

Thanks for listing the chips Peter. I had not been aware that there are two versions running at different voltages until Coen mentioned it. Iv been trying to get my hands on the NEC USB3 chipset datasheet for a long time, they don't make it easy to get a copy. If anyone has it would be really great to have a copy.

With thanks to Nik.d AKA George, see attached.

Peter

PS: How this is related to "NEC" as such was beyond me right from the start. But not important I think.

PPS: Two versions running at different voltages ?

[Nick]

Thanks for listing the chips Peter. I had not been aware that there are two versions running at different voltages until Coen mentioned it. Iv been trying to get my hands on the NEC USB3 chipset datasheet for a long time, they don't make it easy to get a copy. If anyone has it would be really great to have a copy.

With thanks to Nik.d AKA George, see attached.

Peter

PS: How this is related to "NEC" as such was beyond me right from the start. But not important I think.

PPS: Two versions running at different voltages ?

George,

Thanks for responding to the ask for help with these data sheets further up in this post and for your pm.  I'm been trying to get my hands on a copy for ages !

Also Peter thanks for linking them.

Now for some reading 

Cheers,

Nick.

[Nick]

Thanks for listing the chips Peter. I had not been aware that there are two versions running at different voltages until Coen mentioned it. Iv been trying to get my hands on the NEC USB3 chipset datasheet for a long time, they don't make it easy to get a copy. If anyone has it would be really great to have a copy.

With thanks to Nik.d AKA George, see attached.

Peter

PS: How this is related to "NEC" as such was beyond me right from the start. But not important I think.

PPS: Two versions running at different voltages ?

George,

Thanks for responding to the ask for help with these data sheets further up in this post and for your pm.  I'm been trying to get my hands on a copy for ages !

Also Peter thanks for linking them.

Now for some reading 

Cheers,

Nick.

This is great ! I'm just scanning though and already some some ideas that are simple modes and could help performance are coming to mind.

This made me laugh 

"Note 1:
An external modular oscillator cannot be used instead of a crystal, due to aggressive clock management in reduced power states."

Guess we will have to avoid reduced power states then haha.

Nick.

[PeterSt]

Hey Nick, nice. Btw, I didn't look into the PDF's myself yet.

Well, at least that tells that any "one clock" situation should be on the card's side.

Keep up the good work.
Peter

[Nick]

Hi,

This is a post that i’m really pleased to be making, there is a very nice gain in sound quality but I'v had a feeling that there should be a more consistent approach available to tuning the PC and NOS than I could find before.

What is here is the coming together of work on clocks, messings with BIOS settings and some help from the NEC USB chip datasheet the George posted a few days ago.

Lets start off with some sound quality characteristics that come about when tuning USB link clocks using the dexa "heavenly trimmer" haha (first touched on here  http://www.phasure.com/index.php?topic=2784.msg29143#msg29143)




So as the dexa usb clock speed at the PCIe USB card is tuned there are three sound quality conditions that occur:

1)   Sound characteristic 1 is super smooth, it sounds right and very appealing but when listened to you realise that dynamics / transients / weight / scale / and presence have suffered BUT the hardness in 2) has gone which is good.

2)   Sound characteristic 2 has a harsh element in the upper frequencies too much sibilance and on very complex passages particularly with lot of high frequency energy it feels loud in a poor sense.

3)   The “sweet spot”, sound characteristic 3 has smoothness and detail with good portrayal of dynamics / transients / weight / scale / and presence in addition there is detail but without the sibilance and harshness of case 2.
As you tune the dexa clock trimmer the tipping point to move from sound 1) to 2) via 3) (the sweet spot) is very rapid and takes a little work to find where sound 3 is to be found.




So far so good, some folks might recognise the sound types described. I have posted before on the CPU BIOS clock ratio setting and memory speed needing to be carefully set, on thinking these experiences and the dexa trimming about I was starting to see similarities in the sound types produced.

Then whist reading the NEC Data sheet that kindly George provided it was clear that data is being clocked in to the NEC chip from the PCIe bus which nominally runs at 100Mhz, hummmmm.....

So thoughts moved on, what if the main music data transition points can be tuned going backwards up the data stream from the NOS1 all the way back to the HDD, AND what if they behave in a similar way ? Now THAT would be something to work with ! -  a common principle that might be applicable to much of the PC and the USB link into the NOS.





So possible tuning points working back from the NOS upstream to the PC:

a)   PCIe USB clocl speed => NOS USB usb clock speed (using dexa clock trimmer on the PCIe USB card)

b)   PCIe bus speed => PCIe USB card clock speed (set using BIOS BCLK setting)

c)   CPU speed => PCIe bus speed (set using BIOS CPU ratio, (need an Extream mode lntel CPU for this) )

d)   RAM => CPU Speed (using BIOS Ram Speed setting)

So when tried the interesting thing is that each of the above four tuning points have exactly the same effect on sound. When the upstream side of the data transition is fast I get sound chrateristic no 1 when it is slow I get sound characteristic no 2 and then there is a knife edge transition setting which produces the sweet spot 3 in each case !

As an example a change in BIOS BCLK setting of less than 1% hops over the sweet spot setting from sound no 1 to sound no 2. In reality BCLK of 100mhz in BIOS = sound characteristic no 2 and Bios setting of 99.5mhz = sound characteristic no 3, the sweet spot, BCLK of 99mhz gives sound no2.

So I have spent  the afternoon messing about (being suppressed at the similarity of the effect of tuning each parameter) working from tuning points a) to d) above. At the end of this process sound is really excellent, better than I have heard before, silky smooth with ultra detail, coherent and with presence and scale tone and authority.

By a happy coincidence, last night I went to a carol concert at our town's cathedral to hear my daughter sing in a choir. It was a really nice evening but it also meant that I was listening to live church organ last night. Today with the tuning above the sound of reproduced church organ is very very close indeed to what I was hearing last night.





Settings on an ASRock z79 Extreme 4m mobo ended up as follows.

CPU BCLK = 99.5mhz
CPU ratio = 29
RAM 2100 Mhz
Dexa clock at the PCIe USB card 1/16th turn (about) clockwise from standard position (note running against a dexa set to standard trim position at the NOS USB interface.

Final thoughts.

I am strongly suspecting that the above may have something to do with any “wait state” that data encounters as it goes from one PC sub system to the next introducing jitter somehow. I'm also very excited about this, its the first time for me that a consistent approach applied to multiple points where speed can be tuned has resulted in totally consistent effects on sound quality.

Now I’m considering accelerating a project I have started to put a tuneable clock on a HDD, I know what I think it may do when tuned - but will it !! 

Best,

Nick.

[PeterSt]

Then whist reading the NEC Data sheet that kindly George provided it was clear that data is being clocked in to the NEC chip from the PCIe bus which nominally runs at 100Mhz, hummmmm.....

Ha ! Yes. I read that elsewhere already and wondered.

Now I will try to get my head around all of this. Not so easy.
Great thanks Nick !
Peter