Phono signal clipping

[Jens]

I wonder if anybody has experience with optimal setup of the phono sensitivity and how to avoid signal clipping.
My setup is an Oracle Delphi turntable w/Ortofon Kontrapunkt B cartridge connected to a Devialet 200, connected to a Mac Mini running Audacity 2.1.1. 
Technically everything works fine, and I am very happy with sound quality via the Devialet phono inputs set to MC mode - low noise, no hum whatsoever.

I just tried to digitize a vinyl record for the first time, and examining the sampled music in Audacity, I realized that in a few cases during high signal peaks there was noticeable clipping. I had the phono sensitivity set to MC and 300uV on the Devialet. After changing the sensitivity to 600uV, the clipping disappeared - at least for the record I wanted to transfer.
So I am wondering if anybody else has a similar experience, and how did you actually determine the correct sensitivity setting for the Devialet phono inputs (other that the way I did) ?
I am also wondering if the clipping actually takes place in the phono preamp section of the Devialet or somewhere else in the chain. Points of view would be appreciated.
Since a very small amount of clipping is not really audible, I'm guessing that it is very likely that a lot of people have the sensitivity on their phono inputs set wrong, or at least that seems to have been the case for me.
Regards, Jens

[Mohmm]

I wonder if anybody has experience with optimal setup of the phono sensitivity and how to avoid signal clipping.
My setup is an Oracle Delphi turntable w/Ortofon Kontrapunkt B cartridge connected to a Devialet 200, connected to a Mac Mini running Audacity 2.1.1. 
Technically everything works fine, and I am very happy with sound quality via the Devialet phono inputs set to MC mode - low noise, no hum whatsoever.

I just tried to digitize a vinyl record for the first time, and examining the sampled music in Audacity, I realized that in a few cases during high signal peaks there was noticeable clipping. I had the phono sensitivity set to MC and 300uV on the Devialet. After changing the sensitivity to 600uV, the clipping disappeared - at least for the record I wanted to transfer.
So I am wondering if anybody else has a similar experience, and how did you actually determine the correct sensitivity setting for the Devialet phono inputs (other that the way I did) ?
I am also wondering if the clipping actually takes place in the phono preamp section of the Devialet or somewhere else in the chain. Points of view would be appreciated.
Since a very small amount of clipping is not really audible, I'm guessing that it is very likely that a lot of people have the sensitivity on their phono inputs set wrong, or at least that seems to have been the case for me.
Regards, Jens

In the times of good old D-Premier there was a lot of clipping indicated by the blinking power light. Since then their phono firmware became much better. Now, with my 800, I set sensitivity about 10% higher (MC 650uV or 700uV in my case) than the nominal value (600 for my Lyra Delos). There is no clipping anymore except in the most extreme cases. If the nominal value of your MC cartridge is 300uV, a setting of 400uV should be fine. If you set it too high, you'll loose a lot of the signal/noice ratio.

[f1eng]

There is no optimum setting for phono sensitivity since there is no standard for the maximum allowable recording value set as a standard for LP cutting, so a setting which is fine on one LP may clip when playing a different one.
The dynamic range of LP is around 11-bits, so, since the ADC in the Devialet is 24-bit it has much more dynamic range capability than is needed for playing LPs.
I noticed quite a lot flickering of the clipping indicator on my D-Premier using the 0dB output of my cartridge as the sensitivity in the configuration, so halved it.
Once the firmware had added the level display it was easier to adjust the level, but too low is much better for sound quality than too high, though it may give a very different volume control position for normal listening than digital inputs if one listens to lots of pop music which nowadays seems to be hammering the limiters and almost no dynamic range.

I used to do a lot of tape recording. To set levels such that the tape overload was still euphonic without the quiet bits descending into noise was quite an art. With a 16-bit digital recorder it was quite easy, though of course the nice sound of mild tape overload is no longer there unless simulated. With a 24-bit system it is very easy to set levels to capture everything - just avoid clipping. Aim for a sensitivity which gives peaks around -6dB which used to be a general recommendation for setting levels on a digital recorder.

[f1eng]

If you set it too high, you'll loose a lot of the signal/noice ratio.

It would have to be a lot too high to use a "lot" of SNR
Halve the gain is only a 1-bit change and there are 24 to play with to reproduce something with a dynamic range rarely as much as 11-bits.
Some people have a dislike, irrational IMHO, to turn the volume  when the sensitivity is set to avoid clipping but there is no SQ penalty for this.

[marcor]

Hello,

I am re-posting here a question I asked on another thread. I think it can be pertinent to this topic too.

The question regards the level meters on the Devialet.
I have an Airtight PC3 cartridge with a factory suggested output voltage of 0.55 mV. I did some test changing voltage and I noticed that even if the level meters in the devialet are well underneath the yellor/red area the yellow LED that is on the front of the Devialet started occasionally flashing Red signalling a clipping. My understanding was that if the level meter were in the green range I should be in the safe area.
With the suggested settings the 0.55mV I don’t have any red flashing but obviously I need to push the volume more.
Did anyone noticed a similar behavior or can explain me the logic behind this?

Thanks

Marco

[Jens]

hi marco,
I think the Devialet meeters are probably much too crude to be used for anything other than a rough adjustment or trouble shooting. It has been a while since i checked the readings on my own amp - i will do that tonight and post a follow-up.
As previously mentioned the way i found the correct sensitivity setting was to use the USB output feed, record a couple of 'reference' tracks, and then review them for clipping on the pc.
This clearly showed that the 'optimal' setting was not that easy to determine based on the cartridge specs.
Regards, Jens

[ciptip]

Hello there,
Help needed!
I have a strange clipping problem on my 120 and I suppose is due to the phono config; it's strange cause pulled out the phono cables and it was still clipping (those about 10 clipping that you can loudly hear on the speakers each 5 seconds). I configured the phono input for a Rega Apheta at 500mvolt, mc, high; there are not so many config options as in the bigger 200 or 250s. As far as I understood it is suggested that I should put a bigger value than the one stated by Rega.

[Jens]

Hello there,
Help needed!
I have a strange clipping problem on my 120 and I suppose is due to the phono config; it's strange cause pulled out the phono cables and it was still clipping (those about 10 clipping that you can loudly hear on the speakers each 5 seconds). I configured the phono input for a Rega Apheta at 500mvolt, mc, high; there are not so many config options as in the bigger 200 or 250s. As far as I understood it is suggested that I should put a bigger value than the one stated by Rega.

Hi,
Can you try to explain a little better what it is you experience? 
You say that you pull out the phono cable (I assume you mean out of the Devialet, leaving the inputs on the Devialet-end empty?) and you then hear a constant sound (please describe: white noise or hum or ..?) or is it a 'blip' every 5 seconds?
If it is a blip it could be due to having wifi on the Devialet enabled, it's described in the manual. If you pulled out the cable on the turntable end, leaving open-ended cables in the Devialet input, it could be the cable picking up noise or the cable might be defective. Did you connect the separate ground wire correctly from the turntable to the Devialet?

[Jens]

... Actually, how do you display the meters on the Devialet? I have not used this feature for a long time, and now I don't seem to be able to get them to show ....

[marcor]

... Actually, how do you display the meters on the Devialet? I have not used this feature for a long time, and now I don't seem to be able to get them to show ....

By memory, I keep pressed the third button, the one market "invert" on the remote for a while until you enter in the diagnostic mode. Then a short press to change each screen. The last one you encouter are the meters.