• Registered: 2020-01-05
  • Posts: 8

Topic: setting the SNR per channel on the M-32 AD / DA Pro

Hello,

I just got the M-32 AD Pro and the M-32 DA Pro.

I have some questions about setting the Analog Line Levels which can be done per channel which is awesome.

The problem is I don't have a clue on what setting to pick... (+13 dBU, +19 dBu, +24 dBu)

I have vintage analog synths like Roland Juno 106, SH-101.. Korg Poly-61 etc..
Those vintage synths always have more noise...

I also have more modern analogs like the Sequential Circuits OB-6, Deckard's Dream.. they have much less noise..

My digital synths (DX-7, M1) have virtually no noise..

I use vintage effects like Universal Audio 1176LN compressor with quite some noise, but also more modern analog gear like Overstayer Modular Channel with much less noise..

I use vintage drum machines : Roland TR-808, TR-909, 727, 707...

What about my Roland RE-201 Space Echo (using tape)?

Is there a rule of thumb here?
How can I calculate the ideal SNR setting for every piece of gear?

Can I just use +24 dBu on everything?

2 Reply by ramses (edited by ramses 2021-07-29 11:38:39)

  • ramses
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  • Registered: 2012-10-14
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Re: setting the SNR per channel on the M-32 AD / DA Pro

thomas.schols wrote:

Can I just use +24 dBu on everything?

You don't always drive a car in 5th gear, do you?

There are different line levels for consumer and professional audio in use.

See e.g.: https://www.sweetwater.com/insync/under … udio-gear/
[...]Level-matching issues
If you are trying to interface gear and the levels are wacky, then it’s an interface level problem. If you need to connect a +4 output to a -10 input (12dB too hot), then you’ll need a pad (a resistor network) to drop the output voltage. An in-line solution such as the Shure A15AS is ideal for this, offering switchable 15dB, 20dB, 25dB attenuation. Inversely, if you need to interface a -10 device to a +4 input (12dB too low), then the Radial J+4 2-channel Signal Level Driver is the perfect solution.[...]

With the different reference levels it is possible for you to adjust the input optimally to the signal strength of the sender with the goal of avoiding clipping and achieving the highest possible dynamic range and SNR.

If you look into the data sheet of your equipment you might notice, that the different reference levels might have different SNR. Usually with consumer level the SNR is a little bit lower.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14
  • Registered: 2020-01-05
  • Posts: 8

Re: setting the SNR per channel on the M-32 AD / DA Pro

Hi Ramses,

Thanks, that Sweetwater link you provided shows that most pro gear has line level +4. (that was my understanding as well)

That corresponds to 0 dBFS +13 dBu right?

  • ramses
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Re: setting the SNR per channel on the M-32 AD / DA Pro

According to the M32-Pro AD manual the lowest reflevel is +13 dBu, yes pls use that.

• Signal to Noise ratio (SNR) @ +24 dBu, 44.1 kHz: 117.0 dB RMS unweighted, 120.7 dBA
• Signal to Noise ratio (SNR) @ +19 dBu: 116.3 dB RMS unweighted, 119.9 dBA
• Signal to Noise ratio (SNR) @ +13 dBu: 114.7 dB RMS unweighted, 118.3 dBA

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14
  • vinark
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Re: setting the SNR per channel on the M-32 AD / DA Pro

No rules here. Your synths are all way noisier then your AD. So just use 24dbu. If a synth is way to soft then try the other settings.
Or try the other way round. Start with 13dbu and see if any synth give overloads. If no that is the best setting. Might be faster that way.

Vincent, Amsterdam
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BFpro fs, 2X HDSP9652 ADI-8AE, 2X HDSP9632