Best CNF results for system hiss

[Chris Riley]

Hi Craig, you listed in a post way back in 2012 about the basic sequence for LP transfers, with some alterations:

1. Transfer recording flat at 96 kHz
2. Use the Virtual Phono Preamplifier in Diamond Cut to provide the proper EQ Curve to the file
3. Use the Impulse Filter(s) to remove clicks, pops, ticks, etc.
4. Convert file to 44.1 kHz
5. Apply the CNF to reduce (system) hiss (using the sample noise method)

Results are great. But then I apply CD-Prep > Gain Normalize, and there is an audible increase in the hiss. Would you recommend applying CNF a second time, AFTER applying GN? Or, perhaps just the one time, but only after applying GN?

Much thanks,

Chris

[Craig Maier]

I would not recommend applying the CNF a second time. What you are hearing is not an increase in hiss, but an increase in both the signal (music) and the residual hiss since gain normalize elevates the amplitude of ALL signals. One thing that I always do is to use Normalized Gain Scaling rather than just Gain Normalize. I set the Normalize Gain Scaling to about 2 dB below full scale. Of course, it will still elevate all signals, but it will prevent using up the entire DAC counts in the event that your DAC has problems with full scale operation (some do). I hope that makes sense - - - give it a try. Normalize Gain Scaling is also in the CD Prep menu.

[Chris Riley]

Thanks for the clarification on the type of sound. The residual "hiss" that's left over is still quite low, and you'd be mad to listen to the CD at a level for it to be audible anyway, but one less filter is one less filter.

Cheers!

[Marc Hildebrant]

Chris,

In my work, I normalize to the value I want before I use the CNF software. In that manner, I can use one setting for many of the songs since the CNF settings that I developed was related to the amplitude of the song and if all of the songs are normalized then most times the same CNF can be used.

Marc

[Craig Maier]

Sometimes, when I am confronted with a very low level transfer, I will normalize gain scaling to about -2 dB at the beginning of the restoration process. Then, I go through all the steps to restore the audio. When done, I will re-normalize gain scaling to correct the level back to a reasonable range.

Craig

[Chris Riley]

Chris,

In my work, I normalize to the value I want before I use the CNF software. In that manner, I can use one setting for many of the songs since the CNF settings that I developed was related to the amplitude of the song and if all of the songs are normalized then most times the same CNF can be used.

Marc

I might experiment with that approach. Thanks!