• From: Sunbury, Australia
  • Registered: 2023-03-20
  • Posts: 7

Topic: Amp Sims instrument input gain UFX-II Neural DSP

Hi brains trust

Wondering if anyone can advise or clarify the manual. I have a query regarding setting the gain to use with Amp Sims (ie Neural DSP). They advise 12.2dBu (on Apollow interfaces this is achieved by setting the Input Gain on the Instrument to ZERO, calibrated to +13). The below video describes setting the RME input gain to +13, however the Instrument inputs on my UFX-II do not have this option. If I select "Instrument", it sets the gain to 8dB and there is no +13 option.

So...

From the Manual:Maximum Input: Level: Gain 8 = +21dBu, Gain 50 = -21dBu.
Going by that, and doing the math, should I set the gain to 16dB to get the max to +13dBu? Hope that makes sense. (then add the 0.8dB in Neural DSP plugin to achieve 12.2dBu)

I hope my question makes sense....

https://www.youtube.com/watch?v=vTIqslg … %26Pickups

Thanks
Regards, Nathan.

2 Reply by MC

  • MC
  • MC
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  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 25,478

Re: Amp Sims instrument input gain UFX-II Neural DSP

Setting the INST option gives you a max input level of +21 dBu, @ 8 dB gain! So to get +13 dBu as max input level you need +16 dB gain.

Regards
Matthias Carstens
RME

MC's Website

  • From: Sunbury, Australia
  • Registered: 2023-03-20
  • Posts: 7

Re: Amp Sims instrument input gain UFX-II Neural DSP

MC wrote:

Setting the INST option gives you a max input level of +21 dBu, @ 8 dB gain! So to get +13 dBu as max input level you need +16 dB gain.

Ok thanks, so what you're saying is my statement above is correct. Good to know!

  • From: Sunbury, Australia
  • Registered: 2023-03-20
  • Posts: 7

Re: Amp Sims instrument input gain UFX-II Neural DSP

MC wrote:

Setting the INST option gives you a max input level of +21 dBu, @ 8 dB gain! So to get +13 dBu as max input level you need +16 dB gain.


Been playing with this using the Neural DSP plugins.  It seems if I set my Instrument input gain to 17dB, this translates to my DI guitar signal hitting Logic at around -25dBfs - a very low signal. I'm thinking it should be around -13 to -15 or so. Somewhere here the maths is wrong. -25 its even hard to see the waveform even zoomed. Seems far too low.  This doesn't add up.

  • Registered: 2023-06-30
  • Posts: 124

Re: Amp Sims instrument input gain UFX-II Neural DSP

nwarrick wrote:

I'm thinking it should be around -13 to -15 or so. Somewhere here the maths is wrong. -25 its even hard to see the waveform even zoomed. Seems far too low.  This doesn't add up.

SMPTE recommends -20 dBFS as the alignment level for 24 bit recording, EBU recommends -18 dBFS.

This article explains these considerations very well: https://www.soundonsound.com/sound-advi … -recording

Fireface UCX II + ARC USB > ADI-2 Pro FS R BE > Neumann KH 750 DSP + MA 1 > KH 120 A
  • From: Sunbury, Australia
  • Registered: 2023-03-20
  • Posts: 7

Re: Amp Sims instrument input gain UFX-II Neural DSP

unpluggged wrote:
nwarrick wrote:

I'm thinking it should be around -13 to -15 or so. Somewhere here the maths is wrong. -25 its even hard to see the waveform even zoomed. Seems far too low.  This doesn't add up.

SMPTE recommends -20 dBFS as the alignment level for 24 bit recording, EBU recommends -18 dBFS.

This article explains these considerations very well: https://www.soundonsound.com/sound-advi … -recording


So going by the picture on that, a plugin amp-sim wanting to see 12dBu is equivalent to -12dBFS.  But not what the above maths tells me doing the conversion based on my interface specs.

From the Manual:Maximum Input: Level: Gain 8 = +21dBu, Gain 50 = -21dBu.
Going by that, and doing the math, I set the gain to 16dB to get the max to +13dBu.

Hope that makes sense.

But with my Instrument Input on the RME at, say 17dB gain, I'm peaking around -25dBFS (closer to 0dBu).

Still confused.