PlanetZ forums - scopeusers.com

Hi,

I've potentially got a great system, but the low level crackle that I'm getting is driving me mad

My system:

Scope Profesional
Scope 14 DSP booster
Scope Project
SW1000XG (which I need to keep for the VL board and my WX5, though using it to drive the minimax is lots of fun
Noah EX
P4P800 (basic)
NVidea FX5200 running dual monitor
P4 2.6Ghz
1Gb ram
1 x 120Gb SATA
1 x 80Gb PATA
Windows XP
ACPI enabled
HT enabled

I'm using a seperate hardware profile for my music kit with as many services as possible disabled. All the usual Xp tweaks, no screen saver, remote desktop, indexing turned off, optimised for background services. I was having random lockups, but so far so good. But now I've noticed the crackle, which is low level and quite a harsh digital sound but definitely there, and especially noticable when I use scope synths. It's not that noticable with audio from cubase SX surprisingly.

I've been through a long (and painful)process to get where I am now,ie hopeful stable (but not enough testing time to say for definite) which has resulted in re-arranging the cards so that they have their own interupts, sorting out midi over usb on the noah and using midiox to remove active sensing midi messages, latest bios update (don't like motherboard turning into a brick if the power fails), setting affinity for cubase and SFP4 to seperate CPU's.

From what I've read on planetz I should be able to leave ACPI and HT enabled. Two of the scope cards share an interrupt whilst the other is on a seperate interrupt as is the SW1000XG.

I think I've changed the cset.ini file to reflect the scope professional card as first. But in the routing window the Scope board with I/O is listed second from the top and the DSP load shows 1..14,1..14,1..6.

Could this be the problem?
ACPI? I was under the impression that ACPI and APIC on this board was a combo that worked?
Does HT make that big a difference?

I've also used a tool called Double Dawg to alter latency levels for al the cards including the FX5200. The FX5200 was set at a whopping 248, but altering it didn't help, thought it might be worth pursuing in more depth. I suspected a shared irq for USB and a scope card was the culprit but ditching that USB port didn't help.

Any help for a desperate man from you guru's out there would be greatly appreciated.

tia

Rob

my knowledge in XP tweaking is really limited, but the graphcard latency is much too high (imho).
this is not ASIO where a high latency causes lower load - it's the opposite.
The higher the PCI latency, the longer the respective card can occupy the bus and lock out others - your Scope boards

Try with 64 or even 32 for the graphic and increase the Scope values (but only to a reasonable level - whatever that may be...)

cheers, Tom

ps: welcome btw
and while I read about the WX... may I suggest the STW P100 classic plate which will entitle you a free CD100 dynamic chorus delay, which is THAT thing for wind instruments.
Sorry for the shameless ad, but it's a real bargain combo for 99 ($ ?) and the author deserves a little support. We want him to release more stuff, so it's a bit selfish, too

<font size=-1>[ This Message was edited by: astroman on 2004-09-18 20:54 ]</font>

Buzzbang can u post a clip of the crackling?

Hi guys, thanks for the replies

astroman: will try different latency values later today. There's a good article about PCI latency in this months Sound on Sound which is where I read about the double dawg program which allows you to change latency settings in windoze. Also it points out that changing them in the BIOS might not be that effective as the driver will override them when it starts up. I've tried a few different values but heard no real difference, so not overly hopeful that this is the cause

Also your shameless plug for the STW P100 is perfectly acceptable. Having heard the demo (stonkingly good reverb)it's on my list, and now I know that the CD100 is good for wind instruments it's a no brainer

valis: I will post a recording of said crackles later today in presets or modulars and post a link here. My only concern is am I being too picky? The crackle is low level, it's not the evil digital rip that we all know and love. But I can't believe that's it's not caused by anything other that a slightly incorrectly configured system.

she who must be obeyed is dragging me to worship the gods of capitalism (oh the joys of shopping), more later......

cheers

Rob

You don't want any noise though so post up the link so we can have a listen to see what type of noise it is.

You've got a lot of good kit there so you shouldn't be having problems. You may have to look at trying to run in standard pc mode. The p4p800 should allow you to force one IRQ for all scope cards?

Have you tried this tip:

http://www.planetz.com/forums/viewtopic ... &forum=3&7

?

Might be worth a go...stopped the crackling on my system, which has quite similar specs to you own (although I don't have it tweaked the same way as I'm running W2K Pro, not XP)

Royston

Well, I might interupt an otherwise fine troubleshooting session and shamelessly display my absolute lack of knowledge to the world, but are you shure that the noise is in the digital domain? if for instance your headphone cable is too close to the PC, it will pick up noise. Test this by making a recording to CD and go and listen to it on a stereo (which is placed in another room)

Just my 2 cents

Stubbe

Hi - where in London are you?
I've got a very similar system to you - don't know if it's the same crackles I'm thinking of, but graphics seem to have a lot of influence.
I've increased AGP aperture to 256 Mb in bios, only run 16bit at max hardware acceleration.
But the main thing that increased overall smoothness for me was running winXP in Standard PC mode......a world of a difference.
HT won't make any improvement to Scope BTW: it'll only affect Cubase, and it's benefits are probably not all that great.....can't say I miss it.
Cheers.

Stubbe's point is a good one. Do you hear any crackling if nothing is playing, or is it only when something is playing back? Is it constant or intermittent?

Audio buffer / PCI bus problems don't usually give rise to constant crackling...if I plug some headphones into my work PC's soundcard (on the MOBO), there's constant low-level noise regardless of whether I'm playing e.g. an MP3 file or not. (I don't get this on my home DAW).

As suggested, a post of the noise / some further details may well aid Z folk in helping you with this problem further.

Royston

Hi,

thanks for all the suggestions guys:-)

A recording of the crackle is <a href="http://www.planetz.com/forums/viewtopic ... 0">here</a>

This was recorded in cubase using the prodyssey synth in SFP. The crackle is still there when you drive a synth straight from the SFP midi in.

After thinking that it might be related to a digital synch problem last night. I foolishly intoduced another variable into the mix using my A16U over adat:

A16U <---- ADAT-------- SFP (slave)
(master)
|
|
WordCLock
|
|
NOAH ------ADAT -------> SFP
(?)

Bit of a red herring, no real difference, <i>possibly</i> slightly better.

OT: any ideas on the best way to hook up the A16U into the equation. I can use ZLink, but do I need wordclock in my SFP box?

Back to a simple setup. unhook all digital. Midi straight into the SFP, no sequencer req, still crackles. Therefore must be low level, most tempting options are switching ACPI to Standard PC and making the cards sit on a shared IRQ.

Are there any gotcha's on doing this?

I will search plantz.


Royston: there are no crackles when nothing is playing, semi intermittent when playing synths without cubase. Thanks for the tip on Cubase you posted earlier.

Plato: I'm in SW london, and you ? I've tried the 16bit colour depth, will try the aperture as well, and yes I suspect Standard PC is the way to go.

any help appreciated. Further seaching and experimenting call.....

cheers

Rob

Hi,

found the main culprit: HT grrrr. Wish I'd diabled it earlier, doh. I didn't have to move to Standard PC mode... or do I...?

Now all I have is a very faint zipper noise when I move a fader in SFP. Any takers?

thanks for the all the suggestions so far..

Rob



<font size=-1>[ This Message was edited by: BuzzBang on 2004-09-20 16:32 ]</font>

On 2004-09-20 13:48, BuzzBang wrote:
...
After thinking that it might be related to a digital synch problem last night. I foolishly intoduced another variable into the mix using my A16U over adat:

A16U <---- ADAT-------- SFP (slave)
(master)
|
|
WordCLock
|
|
NOAH ------ADAT -------> SFP
(?)

Bit of a red herring, no real difference, <i>possibly</i> slightly better. ...

imho the buzz isn't at all ground related - sounds like a digital sync problem, indeed.
Is the word clock connection properly terminated ?
Are you shure you have 75 Ohm cables and not 50 Ohm RG58 type (as used for ethernet in computer stoneage) ?

You could set Scope to master and slave both A16u and NOAH via Adat, that should work for certain.
I dunno how good CWA's clock in the A16u is - at least people still buy expensive studio clocks for the optimum setup.

At least the difference between Adat and BNC sync would be magnitudes less 'impressive' than your example sound - which isn't a slight annoyance but totally s*cks.
I honestly didn't expect that level of distortion - must be a 15% THD ratio...

But of course non-matching software drivers can sound similiar... unfortunately

cheers, Tom

ps: oops, took me too long to listen and write...
nice you found a solution - that zipper noise is probably the rest left for fine tuning Windows. I've had a similar effect in a 'worn out', messed installation and it disappeared after a clean install.

<font size=-1>[ This Message was edited by: astroman on 2004-09-20 16:53 ]</font>

On 2004-09-20 16:31, BuzzBang wrote:
Now all I have is a very faint zipper noise when I move a fader in SFP. Any takers?

Is the zipper noise there when you move any fader, even the master level on a mixer?
Some of the faders in my setup makes a noise too, but it seems only related to synths and only those controlling something more complex than a simple fader, say a chorus frequency setting. So far, I have concluded that this is inherent in the SFP design, but I will be happy to be proven wrong?

Anyone ?

Stubbe

usb mouse?

On 2004-09-21 02:59, Stubbe wrote:
... Some of the faders in my setup makes a noise too, but it seems only related to synths and only those controlling something more complex than a simple fader, say a chorus frequency setting. ...

right, like setting delay times or room sizes in reverbs - that noise is inherent in the design of the devices.
In my case it was any 'regular' fader movement, menu up and down choice or dragging windows on screen.
The installation had become messed at an unknown point (that noise is not immediately obvious) - and the noise was gone with the next installation.
But I wouldn't suggest a complete new install before actually checking driver and chipset or latency setting. My system was a Win98, not XP installation, so that's not comparable 100%.

cheers, tom

The zipper noise only apprears when moving the fader in the STM1632 which has the adat input from the Noah. But not on the input channel from the ZLink. Bought a Firewire lead and I've now changed to hooking up the A16U via Zlink. Bog standard firewire leads work just fine by the way.

I can drag windows around wiggle other faders inc the master, and no problem, and the audio from the Noah's just fine, just not when I move it's fader, hmmm.

The bottom line for me at the moment is that my system's now running very sweet and I'm very reluctant to do a clean install.... But I have yet to stress test it fully


astroman: I am using stoneage 50 Ohm RG58 cable for the wordclock. Through ignorance rather than choice, doh. But it seems to be doing a grand job. Any reason to change it?

garyb:no usb mouse

now I just need to sort out some good SFP projects and Cubase templates, etc etc etc etc and then music.........

cheers for all the help folks

Rob


<font size=-1>[ This Message was edited by: BuzzBang on 2004-09-21 17:28 ]</font>

yes, I would change the cables to 75 Ohm types - I've seen ethernets comletely fail due to a single non-matching cable.

A bad clock doesn't render the audio into complete crap necessarily - often the difference becomes only obvious if compared to the proper setup as a more clear and transparent sound.

cheers, Tom

When is it necessary to use wordclock? I use an A16U with SFP as master connected with Z-link. Also I use SX,atleast until Tripledat is released. Sometimes I also use a Lucid AD9624 connected with AESBEU. I have to make it the master when I use it. I don't know if I should use some sort of clocking device, or just connect devices with 75 ohm cable,or maybe leave it alone. I don't have any problems,but I don't know if it would sound better if i did things differently. Any advice is appreciated.

the problem is that there's almost no reliable data published about the clock specs of most digital gear - unless it's a dedicated clock, which is rather expensive.

The clock circuitry in the old A16 (non-ultra) at least looks impressive.
It's on a separate part of the circuit board and easy to detect. CWA describes it as '... a high quality device' but without further details.

The Lucid gear is also highly regarded in that context, and probably you have the same 'amount' of information.

At least it's a matter of fact that the more precise the clock, the more detailed and precise is the conversion process.

Jitter (the drifting of the clock pulse in time) is the sum of a lot of small phase errors and the ear is rather sensitive in this context.
But it's also a thing that doesn't sound completely unpleasant (like digital clipping), so there's a high tolerance level, unless one directly A/B compares the sound.

Considering your gear I wouldn't expect tremendous improvements, though advertisers like Apogee (for example) insist that their clock will push any gear, at least slightly
On the other hand it's a frequent observation that 'regular' big studio productions seem to have an 'overall sound' which is difficult to achieve.
A dedicated studio clock may be one reason (among others), but actually I don't know - I'm just counting bits and pieces

cheers, Tom

<font size=-1>[ This Message was edited by: astroman on 2004-09-28 07:25 ]</font>

Thanks very mush Astroman.I am wondering also if I should connect BNC wordckocks.I would only do so if I am using both Lucid and A16U. Otherwise there is nothing to connect the wordclock to when only using A16U.