Re: [LAU] [Music] Delta1010LT card

From: Tim E. Real <termtech@email-addr-hidden>
Date: Mon Jul 18 2016 - 19:59:27 EEST

On Monday, July 18, 2016 10:30:47 AM EDT Robert Edge wrote:
> Do whatever you want. I can't explain it to you any more clearly.
>
> On Mon, Jul 18, 2016 at 10:25 AM, Len Ovens <len@email-addr-hidden> wrote:
> > On Sun, 17 Jul 2016, Robert Edge wrote:
> >
> > If you don't believe me, do this simple test:
> >> feed a 1kHz tone in to the input

I already said that I did that and verified it works.

Unless MAudio had started to make these cards without
 a volume control chip, your distortion is upstream,
 not from the 1010LT card.
Or the card is not being used correctly. Check your settings.
Are you sure the Patchbay/Router tab settings are correct?
Or... your card has a partially fried preamplifier IC? Hey, it happens.

This card has an ak4*** chip with full analog attenuator and amplifier.

(And, uh... if /you/ don't believe /me/ then look at the 'About' tab
 in Mudita24 and see who one of the authors is.)

But seriously, I hope this helps in better understanding the card and
 tracking down the real source of the distortion, which cannot be
 a properly functioning card.

Tim.

> >>
> >> set 'analog volume' control in software to 0dB
> >>
> >> connect to ardour or your choice of recorder with decent metering. set
> >> meter
> >> point to 'in'
> >>
> >> increase volume of test signal until you are getting 0dBFS. no matter
> >> how much
> >> you increase the level of the test signal from here it will continue to
> >> read
> >> 0dbFS. turn the signal generator up a good few dB so you are well in to
> >> clipping.
> >>
> >> record a bit of this. you will see a squared off wave.
> >>
> >> now turn down the 'analog volume' control until you are seeing a nice
> >> comfortable
> >> level. do not change the level of the test signal generator.
> >>
> >> record again.
> >>
> >> the result will still be clipped.
> >>
> >> in fact it will be identical to the first signal you recorded, just
> >> scaled down.
> >>
> >> I mean, you guys do whatever you want, but that is what is actually
> >> happening in
> >> your signal chain.
> >
> > How do you know this is digital and not analog clipping? The result would
> > look the same.
> >
> > signal path:
> >
> > AC -> resitor -> buffer -> digitally -> ADC
> > in pad on amp controlled
> >
> > card analog gain
> >
> > if the input signal after the input pad has p-p higher than amp's power
> > rails allow, the signal will be squared off, just as you are seeing. The
> > gain stage would be a part of the ADC chip BTW. The buffer amp is probably
> > not, but rather a gain stage added to allow the use of mic level inputs.
> > (M-Audio advertise it as a Mic Pre)
> >
> > --
> > Len Ovens
> > www.ovenwerks.net

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Received on Mon Jul 18 20:15:02 2016

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