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Where has my Recording Level Slider Gone?

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Paul Sanders (AlpineSoft):
We get a lot of questions about this. The fact is that many USB devices (including most Ion turntables, the Behringer 202 and the NAD-PP4) have no recording level control that can be adjusted via VinylStudio's recording level slider.  This means that if the signal is be clipped (i.e. exceeds the maximum level that your PC can handle) on loud passages of music there is nothing VinylStudio can do about it.  This is because the signal is clipped before it even enters the PC.

Some devices, such as the NAD PP-4, offer a gain control on the front on the unit and this is a simple and effective solution.  Others (most, in fact) do not, which can be awkward.

At the software level, VinylStudio deals with this in one of two ways:

* If you check the 'Use WASAPI when recording' box in the Check Level dialog, then the slider is disabled and whatever it then happens to display is irrelevant - VinylStudio just uses a straight-through signal path.
* If you uncheck that box, then VinylStudio displays a 'Set Digital Gain to 1' button and you should click it.  Any other setting of the slider is sub-optimal.It is tempting to reduce the slider setting if VinylStudio tells you that the signal is clipping, but all that does is mask the problem. If clipping is occurring, the flat tops of the waveforms will still be there and if they are severe enough, audible distortion will result.  All that turning the slider down achieves is to hide them from the clipping indicator.

Some USB devices (including the PP-4) also incorporate traditional (analog) line-out sockets.  If so, you can run a cable like the one pictured here to line-in on the soundcard built into your PC or (older) Macs.  If the clipping is severe this is often the best solution.

If, on the other hand, your recording is too quiet, you can boost the playback level after recording by normalising the recording as shown on our videos page.  Boosting the input signal with the recording level slider (i.e. by moving it above the 'Set Digital Gain to 1' setting) is then also a viable solution, but please be careful. Never, ever, set the slider below that level if that button is on show, for reasons already given.

Please note that XP users are unaffected by any of this.  There is still no slider, nor is there any need for one as XP does not meddle with the input signal in any way.  And it works the same way on the Mac.

Note: Some of the posts below refer to older versions of this post, which has now been substantially revised.  Most of them therefore probably don't make much sense anymore.

Paul Sanders (AlpineSoft):
Question: You say there is no point providing a recording level control in software for USB devices.  Why?

The reason why this doesn't work (or it least, doesn't do anything useful) is that the signal is digitised before it enters the PC.  The digitised signal is limited to 16 bits per sample and if it exceeds that level it will be clipped inside the USB device.  After it reaches the PC, all that can be done is to scale the numbers down.

To put it another way. each sample is just a number and if it exceeds 16 bits (-32767 ..  32767), the excess cannot be transmitted across the USB bus.  The glass is full.  Period.

Muddler:
Could you please clarify something regarding the NAD PP-3 - you say that the device implements "soft-clipping".  When recording from the device, the software registers literally a thousand or more clips each song.  My cartridge outputs 5,5 mV.  If your software is registering clips, there are indeed clips, correct?  In other words, this "soft-clipping" isn't stopping clipping when your software registers clips, right? 

Fortunately, I have an alternate recording option, so if the answer is that I'm going to lose audio quality using the PP-3 as a USB out device, better to know now before I do a lot of recording only to play audio back later and wonder why it sounds off.   

Thanks.

Paul Sanders (AlpineSoft):
Actually, I can't.  I will talk to NAD about this and post back to this thread, but I think the idea is that the waveform is rounded off somewhat, rather than being just sliced off like the top of an egg.  I believe the processing is analogue (a bit like a valve amplifier, which has some soft-clipping characterics) rather than digital, but I could be wrong about that.

As for using an alternate recording option, I would record the loudest thing you can find using both alternatives and have a listen on headphones.  Also record something quiet (or even silence) and listen to that.  Hiss and hum pickup can be a problem with vinyl recordings and the PP-3 has a particularly low noise floor.

dmerrick:
I Use the ART USB Phono Plus II.

With Version 6 my input is clipping 100% all the time.
My preamp has built-in clip indicators, they work as they should.
But something is different.

This has made the software unusable for me.
Is there a link to DL Ver 5 from somewhere?

Without that gain control, I can't record.

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