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[soundcheck]

Hi folks.

I don't know if this is a bug at all. Anyhow. I just want to check it out.

I am shutting down the Windows Audio Service under system control/administration/services to make sure
that MS is no longer involved in any audio relevant context.
(This is also a good test to check if an application uses e.g. poor Windows Volume control, which won't work afterwards!
MC passed that test!  )
I know it is a weired setup. For me it was the easiest way  to switch MS off and just use the external sound-device via ASIO.

My USB ASIO driver is still working. MC also keeps working well. The internal volume control is also working. I am happy with the result!

Still - When starting up MC, it runs into a strange 60s timeout. It completely hangs for a minute and after that it works perfect.

Perhaps there is an answer to this behaviour.

Cheers

[Matt]

There's no need to cripple Windows.  MC will be bit-perfect either way if you use ASIO.

At startup, MC may be "optimizing the volume" (max software volumes and use the hardware volume for the best S/N ratio)

You can disable this in Options > Startup

[soundcheck]

Matt.

I rather cripple Windows, than Windows crippling my sound output. And what's better than just switching all the mess off. 

I configured this setup for my very specific Audio HW-profile only. On the standard HW-profile I use MS Audio the classic way of course.

Thx for the hint on the volume optimisation. I actually did not understand the explanaition in the help file, saying it combines
wave and master volume control. Shouldn't it say it combines MC and Windows volume control. What is maxed than? MC Volume or Windows
volume?
The way I understand it. You are combining MC internal 32bit float volume control ( if I recall it right?!?) with the
rather limited windows volume control to improve SNR.

Cheers

[JONCAT]

Matt,

I wouldn't mind hearing from you if Alex B's comments on bit perfect ASIO playback (sending via digital to an external DAC) are accurate:

"At least these options need to be disabled for bit perfect output: everything in DSP Studio, Internal Volume (maxed out = bit perfect), Cross-fade and Do not play silence (leading and trailing)."

This, to avoid MC jumping in with 32bit dsp....
Myron tested MC for bit-perfect playback but I am wondering if a user really needs to disable the useful DSP features that Alex B mentioned: remove leading trailing silence, crossfade, etc.

Myron said:
"As for the audibility of differences between ASIO and other output modes I personally have not yet made the comparison.  However, I can say with 100% certainty that ASIO in MC passes the DTS and AC3 'bit-perfect' test.  Direct Sound and Wave Out do not.  I've tried this with two different M-Audio cards on two different machines.

In case you're not familiar with this test, it involves playing a DTS or AC3 encoded WAV file out via the digital output of a sound card to see if an external processor can decode the audio.  Any manipulation of the data, such as volume control, will result in the processor not being able to decode the audio."

v/r
DC

[Matt]

Matt,

I wouldn't mind hearing from you if Alex B's comments on bit perfect ASIO playback (sending via digital to an external DAC) are accurate:

"At least these options need to be disabled for bit perfect output: everything in DSP Studio, Internal Volume (maxed out = bit perfect), Cross-fade and Do not play silence (leading and trailing)."

You should know that Alex is always right.  He's amazing.

Obviously cross-fade or silence trimming isn't "bit perfect" since it changes the source signal, but once a fade is over or silence is over, MC will be bit-perfect again.  During the time it's changing the signal, it does everything in 32-bit space so there's way more headroom than even a studio engineer would need.

[JONCAT]

Great news....perfect way to do it. Deep down, of course, I knew he was right. He ALWAYS is...but I am glad I asked since we can effectively leave those funtions enabled if they are only going to un-bit-perfect the stream momentarily...

..hey congrats on your first! Our 1st born son is 3 months old next Monday. Enjoy the ride, it's amazing (as you know). 

Jonathan

[soundcheck]

Hi there.

As far as it comes to bit perfection, we had that issue before.

This can be measured up to  "last point of control". It is most probably a fact that a bit perfect stream leaves MC.
What happens afterwards stays a secret, because MC doesn't get any feedback from e.g. an external DAC when driven over USB telling about buffer under- or overruns,
if the comunication is unstable.
You don't have a clue what will be received by an external DAC and what the DAC is doing with the stream.
You don't no how much Jitter is induced to the stream

This will only work if you've got an external  master clock out there running the PC, soundcard and application as slaves. You can configure e.g. pro applications, such as Samplitude, for external clocking.

BTW. I tested the application behaviour, whith "optimised volume swicthed off". It still runs into the same timeout. Never mind!

Cheers

[JONCAT]

This hang you have is strange; I used to hang for maybe 10 seconds sometimes with 11 & I attribute that to my databased being hashed or something. MC12 has been incredible: blazing fast startup times, stability, and getting better every day.

I hate to play the old "stress test" card, but have you tested your memory and hardware with Prime95 and the windows based memory tester Matt recommended here on the forum. I can try to dig it up if you can't find it, but you could always use a dos based app like memtest86+.....

I don't have a master clock but I do have an EMU usb 0202, 1212M, and Benchmark DAC1...but I guess I can't test until I have a clock.

Benchmark wants bit-perfect sent to the DAC1, to prevent jitter, but will upsampling introduce jitter with 32bit in MC? The Benchmark can take anything you throw at it, so why not upsample or at least do 24bit in the DSP.

DC

[soundcheck]

DC.

I am wondering what the bit depth has to do with jitter.

It is the samplingrate which plays the main role here.
Moving from 44,1 to 48 just eleminates the uneven distributed samples over the USB timing scheme, which apparantly goes together with the uneven 44.1khz sample rate.

IMO 24bit would be the choice if you use the MC internal DSP volume control instead of an external control or in case you got 24 bit base material.

Interesting read for USB DAC owners (not new though): http://www.planetanalog.com/showArticle.jhtml?articleID=12801995