db limitation

[erzane]

hello,
I would like to limit the db amplitude during the recording of a vinyl to -3db.
Whitch menu should I Try?

My material: Technics MKII - Onkyo CR-N755 - Pro-Ject USB-V - VAIO VPCX11S1E

[pandy]

Use Input level mixer to set input in a way that analog input signal (with highest possible level) will never not exceed -3.0103dBFS.

[erzane]

thanks for your reply
do you have a pic of the input level mixer pls?
my menu is in french

[pandy]

Pro-Ject USB-V is equipped with manual knob so try to use it first, you may try to "calibrate" your signal path - try to select vinyl with highest level and try to adjust gain to match this approx -3dBFS level - you can use for this for example https://www.roomeqwizard.com/features.html or any real time level meter suitable for your configuration.

[erzane]

Yes, in fact I use the manual pot of the Pro-Ject first.
When the song is playing I watch carefully the db. on the level meter and I test the db level by pushing F10.
When I see the db fierce don't goes more far than around -6 to -4db I start to record.
Sometimes there is some high level peak during a very small time whitch goes to -2, or -1db (but it's very rare, it depends of the age of the vinyl, I think those kind of peak comes from some background acute noise)

So, after recording I do that:
My current track is around -6/-5db when finishing recording (step#1).
I amplify it a little bit to -3db (step#2).
And I cut all the thiner lines which exceeds by doing >Effetcs >Amp & Compress >Limit Fix
and I set the limit to -3db (step#3).

What do you think about this method? I'am just wondering if I do well, because I am afraid that fixing a limit to 3db by cutting exceeding peaks takes off some infos of the quality of the track.. ( I don't hear it, but it's only in my mind). The fact is that I want to amplify the volume level (with the virtual pot) like this I am sure to have a strong but safe saturation free volume level when playing. (I notified that vinyl sound is lower than cd one).
p.s. I record in 88khz - 16bit flac

Step#1


Step#2


Step#3


Virtual Amplifier Pot


Level Meter


Perhaps it exists an easier method to regulate the volume level. I found this video, but don't really understand what this guy is doing, but it sounds good (from 4:50 to 6:00min)
https://www.youtube.com/watch?v=ewDe0i_qnNo

[pandy]

Pro-Ject USB-V is quite limited by using only 16 bit AD converter, side to this accordingly to specification Pro-Ject USB-V support maximum 48kHz sampling rate - both factors imply that you must be very accurate in setting level and you should avoid any additional processing. Small peaks if then not going over 0dBFS are acceptable.
I would consider some replacement for Pro-Ject USB-V - something capable to perform 24 bit acquisition - this should create situation where level settings will be less critical.
Personally i apply sometimes gentle (maximum second order) IIR filter with almost linear phase characteristic (such as Bessel) and reasonable cut frequency (16 - 19kHz depend on content) - this should nicely show if there is any risk of digital clipping (always check peak peak and RMS digital level, peak to peak shall never go over 0dBFS and RMS shall never be higher than -3dBFS).

[erzane]

About your processings:
-IIR filter - whitch menu is it?
-how to check ''peak to peak'' and ''RMS'' digital level?

About general settings during recordings:
-what is MM & MC button? on mine it's on MM as default
-should I go until 48khz if my pro-ject is able to do it? or 44 would be fine to?

Btw, when I record on 48khz, I have this message. It seems some of my machine handle only 44khz..


p.s. around -10db, the level meter beginns to be yellow. what's the best colour to your eyes? do you actually records vinyls around -15db when it stay yellow, -10db when still on the green, or -6/-3db (begin to be orange)?
To my eyes, the green colour is always more safe, even is sound when listening is less louder. I am just wondering if the yellow colour is still ok. I read about -6/-3db is the most common, but I notified it's almost red, since it begin to be orange...
Just would like to know your opinion on that.

[pandy]

IIR Filter is digital analogy for classical analog filters - most common characteristics are Bessel, Butterworth and Chebyshev - location depend on sound editor you intend to use.

Peak to peak and RMS are usually located in statistic window also depend on software used as sound editor.

As a sound editor you may use SoX (command line based) or some free editor like Audacity.

MM is Moving Magnet pickup and MC is Moving Coil type pickup - you should select proper one - depend on your pickup - they have different frequency correction characteristics so this selection is very important also they are significantly different in terms of electrical signal - MM cartridge gives signal 20 - 100x times stronger than MC - usually MM are lower grade pickups (MC are usually more accurate).

I'm no french speaking so i'm unable to understand this message about 44.1kHz.... sorry but Pro-Ject USB-V is definitely capable to sample with 48kHz so perhaps this some issue with configuration or drivers?

Rule is simple every 6dB is 1 bit of audio, in your case Pro-Ject USB-V is only 16 bit it means to maximize dynamics you should set level very accurate (to fully use AD dynamic range especially that ADC in Pro-Ject USB-V is PCM2904 and this mean relatively poor dynamic range around 90dB) in digital audio peak signal level shall never exceed 0dBFS, and should not exceed -3dBFS for RMS signal level, also you should stay with signal level RMS value above -9dBFS so -6 ... -3dBFS sounds OK in your case - for 24 bit ADC this may be relaxed as usually 24 bit ADC offer few dB higher dynamics (usually around 100 ... 110dB which is more than 16 - 18 bit).
It is quite important to remember that noise not correlated with signal (i.e. natural noise present in recording plus noise from equipment) works as dither and usually it help to keep low level details (but usually dither level should not exceed 9 - 12dB unless aggressive noise shaping is used).

This video may be nice to watch as some of your question may be nicely answered - probably one of the best video dedicated to this topic.
https://www.youtube.com/watch?v=cIQ9IXSUzuM

[erzane]

about sound editor I use: adobe audition

about MM and MC: how can I verify what pickup I have?
on the Pro-Ject USB-V Manual, they say that MM is the basic setupbecause most of the systems wrork with it, that's why they put on MM as factory settings (as default).

about my configuration or drivers:
the message wants to say that the basic settings of my sound card is 44khz. If I record on 48, the pc will automaticly ''downscall'' it. I use this term, but it means, it will put it to 44, and not keep 48, by doing a ''resampling''.
Where can I know the specs of my soundcard? Like this you can see what they are.

about the db level. I see. Now, if I record the track with signal level RMS value above -9/-6dBFS, and after recording, when listening, I find the volume is not high enough, can I amplify it on adobe audition with the virtual ampifier pot?




thanks for your explanations and the video

[pandy]

In Adobe Audition analog filters (digital implementation) are located under 'Effects' > 'Filter & EQ' > 'Scientific Filters' > Bessel, Low Pass, Cutoff 20000Hz, Order 2 - this should expose eventual clipping.

Amplitude Statistic is located under tab 'Window'

I'm almost sure that you have MM type cartridge.

Perhaps there is some configuration software for Pro-Ject USB-V where sampling rate can be set? Definitely 48kHz should be supported.

Adjusting level of signal in digital domain usually lead to some loss (with few exceptions) of quality Of course it is possible but if you pursuing highest quality then i recommend setting signal level in analog domain before ADC.

[erzane]

Thanks for all infos

Btw, I was thinking my issue concerning the fact that I cannot go to 48khz is due to the sound card of my VAIO.
But I see there it can handle 48kz
http://realtek.info/pdf/alc262.pdf

But, since I am actully buying a brand new PC, I could buy a PCI sound card which can go to 24bit. Like this I could record in 24bit/44khz, what do you think about this one?
https://www.microspot.ch/msp/fr/composants-pc/cartes-son/creative-sound-blaster-audigy...24--0000762225
p.s. the only issue would be the distance between my pre-amp and my PC. Do you think a 3m or 5m long usb A-B will loose signal quality?
Btw, my actual PCs soundcard can handle 48khz.