Author Topic: ADC with adjustable input sensitivity  (Read 10476 times)

mgd

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ADC with adjustable input sensitivity
« on: May 15, 2010, 11:34:26 am »
I have a NAD PP3 phono RIAA preamp with USB interface which I use for recording my vinyl records to harddisk. However, I am a bit disappointed that I am not able to adjust the signal level that goes to the ADC.

As you know different records are recorded at different levels and cartridges has different output voltages and without being able to adjust the level of the signal that reaches the ADC, I am not able to fully utilize the resolution of the ADC.

Is anybody aware of a decent ADC with USB output which also offers the possibility to adjust the signal level before the signal enters the ADC. (If it also incorporates a RIAA preamp stage that would be fine, but it is not strictly necessary as I can still use the RIAA preamp of my NAD PP3.)

Any help will be greatly appreciated.

Regards,
Martin

Paul Sanders (AlpineSoft)

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Re: ADC with adjustable input sensitivity
« Reply #1 on: May 15, 2010, 12:30:25 pm »
The Griffin iMic will do it, but it doesn't work with Vista (it's OK with XP and Windows 7).

Alternatively (and cheaper!), you might try running a cable from the line out sockets of your PP-3 to line-in on your soun card.  This often gives excellent results.  The cable you need is pictured here:

http://www.alpinesoft.co.uk/VinylStudio/connecting_up.aspx

HTH.

mgd

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Re: ADC with adjustable input sensitivity
« Reply #2 on: May 15, 2010, 01:13:25 pm »
Paul,
Thanks for your reply!

> Alternatively (and cheaper!), you might try running a cable from the line out
> sockets of your PP-3 to line-in on your sound card.

I thought of this as well, but would like the ADC to reside outside of the noisy PC environment.

> The Griffin iMic will do it, but it doesn't work with Vista (it's OK with XP and Windows 7).

Do you or anyone else know whether the iMic has a sliding/analog level adjustment knob, or is it only a discrete switch between mic and line level? I am not able to figure it out from the specs and images on the web page where it says:

  iMic supports both mic and line level inputs via a selectable switch, ...

I found some specs on their support page for the resolution and sample rate:
http://www.griffintechnology.com/articles/15-is-the-imic-a-digital-input-is-it-24-bit-48khz-mac

It seems this is a 48KHz/24bit device, right?

Have you tried it yourself? And if "yes": do you find the sound quality to be good?

Lastly, I guess I forgot to be more specific about what I am looking for:
I would like a device that offers at least 44.1KHz/16bit/stereo but 48KHz (or maybe 96KHz) and 24bit would do not harm to have as well. But a good quality 44.1KHz/48KHz device is preferred over a mediocre 96KHz device. (However, we are still talking about entry level equipment below £130/€150 if it includes a RIAA preamp and at a lower cost if it has no RIAA stage.)

Also, I found this device which is a RIAA preamp, analog gain control and ADC with USB output.
(Cost is €101 + shipping.)
  ART USB PHONO PLUS V2
  http://www.thomann.de/dk/art_usb_phono.htm

Is it a device anyone has heard of and knows whether it offers a good sound quality?

Regards,
Martin

P.S. I need to use the device on a Mac as well as on a PC. Forgot to mention that initially.

mgd

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Re: ADC with adjustable input sensitivity
« Reply #3 on: May 15, 2010, 01:22:33 pm »
I just found some more info about the iMic and it has only a discrete input level selector that can be set to either line or mic (in which case the internal preamp is turned on).

However, I would like to have a turning knob or slider that allows me to precisely adjust the input level before the signal is converted in the ADC.

So, do you, Paul, or anybody else know of such a device with these requirements:
  44.1KHz/16bit/stereo but 48KHz (or maybe 96KHz) and 24bit would do not harm to have as well.
  But a good quality 44.1KHz/48KHz device is preferred over a mediocre 96KHz device.
  Cost: below £130/€150 if it includes a RIAA preamp and less if it has no RIAA stage.

Also as I mentioned earlier, I found this device which is a RIAA preamp, analog gain control and ADC with USB output. Cost is €101 + shipping.
  ART USB PHONO PLUS V2
  http://www.thomann.de/dk/art_usb_phono.htm

Is it a device anyone has heard of and knows whether it offers a good sound quality?

Regards,
Martin

Paul Sanders (AlpineSoft)

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Re: ADC with adjustable input sensitivity
« Reply #4 on: May 15, 2010, 02:42:38 pm »
Hi,

The iMic does have a proper hardware level control.  I have one here and it works well.  I have no personal experience of the ART USB device you mention but if you ask this questions at Hydrogen Audio I imagine you will get some informed replies.  I will ask Apple whether OS X does indeed limit USB devices to 16 bits, and I will post their reply back here.

But try it through your sound card.  Make a recording of a quiet passage (or, indeed, nothing at all) and check for background noise.  There might not be any - there isn't on my own recordings, which were made on a desktop PC, but there is if I do this on my MacBook.

mgd

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Re: ADC with adjustable input sensitivity
« Reply #5 on: May 16, 2010, 04:05:50 pm »
Hi Paul,

Thank you for your reply.

Ok, so I guess "hardware level control" means that you can control the recording level from e.g. Vinyl Studio and this will change the level in the hardware before the analog signal is sampled (and not simply in Windows after it is sampled.)

Thank you for your tip regarding the Hydrogen Audio forum. I will try to ask the question there.

I might also try to give my internal sound card a shot -- although I'm using a MacBook Pro and you said that you had noise on your MacBook.

Regards,
Martin

Paul Sanders (AlpineSoft)

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Re: ADC with adjustable input sensitivity
« Reply #6 on: May 16, 2010, 04:54:12 pm »
Well, for the cost of a cable, why not?  You really have nothing to lose.  And yes, as far as I can see the level control in the iMic operates before the signal is digitised (and the level control slider in VinylStudio is operational with this device).

Paul Sanders (AlpineSoft)

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Re: ADC with adjustable input sensitivity
« Reply #7 on: May 19, 2010, 02:17:21 pm »
Update: I did a bit of digging about the iMic and you are right: it does *not* support 24 bit audio on the Mac (or indeed anywhere else).  This appears to be Griffin's fault, not Apple's.

Perhaps you could let me know what you learn from HA about a suitable alternative device (or post a link to the thread back here so that I can monitor it).  Thanks.

mgd

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Re: ADC with adjustable input sensitivity
« Reply #8 on: June 21, 2010, 07:31:03 pm »
Hi Paul,

I haven't forgot you I just wanted to give my NAD PP3 a shot. If I post something on the HA forum I will off course let you know what I find out.

Regards,
Martin

Paul Sanders (AlpineSoft)

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Re: ADC with adjustable input sensitivity
« Reply #9 on: June 21, 2010, 07:56:01 pm »
Hi Martin,

I did in fact learn of another device - the ART USB Phono Plus - which has a manual level control (i.e. a knob you can twiddle). At around £80 including a phono preamp that might be worth a look.  According to ART's website, this is compatible with Vista but it always pays to check.

http://www.artproaudio.com/products.asp?type=90&cat=13&id=128

Rgds - Paul Sanders.