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@xxxxxxxxxxxxx> 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 _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
