Analog Line-In Recording Question

dialcee · Feb 15, 2005, 01:47 PM

Hi, I use KX 3538h and a SB0222 card. I plan to record my vinyl collection via line-in, using the headphone output of the phonograph (it has no other low level output) -which is a little noisy. I will record at 48 KHz/16 bit. I plan to use Cool Edit Pro to upsample to 48/32 and edit/denoise the files. So I want all the edits to be in 48/32 bit domain. I read this guide:
http://kxproject.lugosoft.com/tech.php?language=en
Quote from it:

Quote:

Volume Levels and kX DSP settings

In order to avoid any software processing and audio quality loss, the volume levels should be set as follows:

Master Level: 100%
Wave level: 100% (both, in kX Mixer and in your audio application)
Master Recording level: 100%
[color=Red]All inputs and outputs are to be set to '0dB' or muted[/color]
To avoid recording 'What U Hear', set Wave, Synth, FX1 and FX2 Recording Levels to -inf

I am a little confused by this (red line above) since I thought that the input level is like an amplification/atenuation in analog domain, before the analog-digital conversion.
So my question is: the level of AC97 recording does modifies the volume after the digitization (so it's better to leave it at 0 dB, because it's better to raise the volume in 32 bit domain) or before so I can go up to +12 dB (which I would preffer, since the amplification in my card is less noisy than the phonograph's).
Thanks in advance!

TravelRec. · Feb 16, 2005, 07:17 AM

Hi!

All faders in kX-Mixer work as digital attenuation or amplification. Since the analog stage amplifies the input by 1 the card samples at 0db while you feed a signal with 0db (ideally). It´s recommended to leave all faders at 0db to avoid distortion of input stages or in the DSP itself due to unmatched levels and to have as much as possible usable magnitude. If your source is a headphone amp, there is no way to get away the noise which the amp introduces (except externally with a denoiser or a better low-noise amp). Best is to feed the card with a signal a bit below 0db (to have a small headroom for vinyl crackles) and after that denoise the signal a little and compress it. Additional you can insert an APS expander between line in and record in (in the DSP) and tweak it that it works as a noise gate, so you can get a better S/N in low signal parts. BTW: don´t forget that vinyl records can´t have a better S/N than 60db, physically limited.

dialcee · Feb 17, 2005, 06:55 AM

Many thanks for your answer and tips.

dialcee · Feb 18, 2005, 12:23 AM

Hi, it's me again.
Looking at about info in kx mixer, at some point it says this about my card:
DAC resolutions : -16-bit- -18-bit-
ADC resolutions : -16-bit- -18-bit-
Does this mean that I could capture sound at higher bit depth than 16 bit? If yes, how? Recording in cool edit pro as 48Khz/32 bit would do it?

ROBSCIX · Feb 18, 2005, 01:11 AM

I your using CEP..keep your signals within -3db to -6db this leaves headroom for snaps,pos and crackles also for peaks in the line..ideally I don't think using the headphone amp is a good idea..as it is probably very noisy and narrow in frequency response

TravelRec. · Feb 18, 2005, 07:12 AM

Quote:

Originally Posted by dialcee

Hi, it's me again.
Looking at about info in kx mixer, at some point it says this about my card:
DAC resolutions : -16-bit- -18-bit-
ADC resolutions : -16-bit- -18-bit-
Does this mean that I could capture sound at higher bit depth than 16 bit? If yes, how? Recording in cool edit pro as 48Khz/32 bit would do it?

Not really - you can record via WMM (Windows) what you want - it´s still 16Bit at the selected frequency - still resampled by software. Via ASIO you´ll get 16Bit at 48kHz (wich is the best sound I think). For your vinyl that responses around 16kHz maximum I think it´s quit okay to record 16/48 !

dialcee · Feb 18, 2005, 11:03 AM

Quote:

Originally Posted by ROBSCIX

I your using CEP..keep your signals within -3db to -6db this leaves headroom for snaps,pos and crackles also for peaks in the line..ideally I don't think using the headphone amp is a good idea..as it is probably very noisy and narrow in frequency response

Unfortunatelly this is all I got. Finding or buying another phono player these days is not an option for me, I don't have more than 150-200 vinyls and besides, I'm pretty happy with the output, it goes up to full frequency range (24 khz) when I record in 48 Khz.

Quote:

Originally Posted by TravelRec

Not really - you can record via WMM (Windows) what you want - it´s still 16Bit at the selected frequency - still resampled by software. Via ASIO you´ll get 16Bit at 48kHz (wich is the best sound I think). For your vinyl that responses around 16kHz maximum I think it´s quit okay to record 16/48 !

So, is a recording via ASIO at 48 KHz/16 bit better than one via WMM at 48/16? Because I thought that ASIO is good when you want low latency, and thats all. Anyway, CEP has no ASIO input, do you know a cheap recorder program (ideally free) that has ASIO input?

**dj_stick** · Feb 18, 2005, 11:06 AM

krystal is one i think

dialcee · Feb 18, 2005, 07:49 PM

Thanks!

Feb 16, 2005, 07:17 AM	#2
TravelRec. Alternative Audioproductions Join Date: Sep 2003 Location: Germany / Sachsen-Anhalt Posts: 1,710 Rep Power: 56	Hi! All faders in kX-Mixer work as digital attenuation or amplification. Since the analog stage amplifies the input by 1 the card samples at 0db while you feed a signal with 0db (ideally). It´s recommended to leave all faders at 0db to avoid distortion of input stages or in the DSP itself due to unmatched levels and to have as much as possible usable magnitude. If your source is a headphone amp, there is no way to get away the noise which the amp introduces (except externally with a denoiser or a better low-noise amp). Best is to feed the card with a signal a bit below 0db (to have a small headroom for vinyl crackles) and after that denoise the signal a little and compress it. Additional you can insert an APS expander between line in and record in (in the DSP) and tweak it that it works as a noise gate, so you can get a better S/N in low signal parts. BTW: don´t forget that vinyl records can´t have a better S/N than 60db, physically limited. __________________ Always take a look behind.

Feb 17, 2005, 06:55 AM	Thread Starter #3
dialcee DriverHeaven Newbie Join Date: Dec 2003 Posts: 10 Rep Power: 0	Many thanks for your answer and tips.

Feb 18, 2005, 12:23 AM	Thread Starter #4
dialcee DriverHeaven Newbie Join Date: Dec 2003 Posts: 10 Rep Power: 0	Hi, it's me again. Looking at about info in kx mixer, at some point it says this about my card: DAC resolutions : -16-bit- -18-bit- ADC resolutions : -16-bit- -18-bit- Does this mean that I could capture sound at higher bit depth than 16 bit? If yes, how? Recording in cool edit pro as 48Khz/32 bit would do it?

Feb 18, 2005, 01:11 AM	#5
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	I your using CEP..keep your signals within -3db to -6db this leaves headroom for snaps,pos and crackles also for peaks in the line..ideally I don't think using the headphone amp is a good idea..as it is probably very noisy and narrow in frequency response

Feb 18, 2005, 07:49 PM	Thread Starter #9
dialcee DriverHeaven Newbie Join Date: Dec 2003 Posts: 10 Rep Power: 0	Thanks!