Gain Staging/Mixing Troubleshooting

[highkrausen]

I just got a 16A. Plugged in all my devices: eurorack, Digitakt, a bunch of external synths, Guitar pedal loop, etc. The external synths (hydrasynth, etc) all appear to have appropriate (expected) gain/input levels. However, a few of the devices, like eurorack and Digitakt specifically are SUPER quiet and the computer audio is in super loud. I have to turn the level on the eurorack/Digitakt devices up to 100% and even then +12db on the trim or channel fader before I hear anything. Eurorack is outputing Line Level.

Any ideas what to troubleshoot? Also, on my external synths....at 0db on channel and main mix faders, the sound are loud through the monitors...but barely hit -24dB in the Mix. Computer audio is coming in is SUPER loud coming out of the monitors... had to turn computer audio down to 10% and monitors down to their lowest setting. It seems all over the board. I’m sure it’s me, but could use some help troubleshooting. Thanks!

[mikehalloran]

I don’t know the 16A but I suspect that, like most recent interfaces, the Line Inputs are expecting to see line level signals. If your devices are not providing that level, DI boxes may be the answer. Check the specs.

The M4 and all the new “Fast USB 2” interfaces from all manufacturers are publishing +18 or +16 dBu input levels. It doesn’t matter that the marketing departments say you can just plug in your keyboards and synths.

I just looked at the web site. Line inputs only. Check the manual. Some MOTU interfaces such as my 828mkII allow one to change the gain stage on input channels. Again, I don’t know the 16A.

[highkrausen]

I don’t know the 16A but I suspect that, like most recent interfaces, the Line Inputs are expecting to see line level signals. If your devices are not providing that level, DI boxes may be the answer. Check the specs.

The M4 and all the new “Fast USB 2” interfaces from all manufacturers are publishing +18 or +16 dBu input levels. It doesn’t matter that the marketing departments say you can just plug in your keyboards and synths.

I just looked at the web site. Line inputs only. Check the manual. Some MOTU interfaces such as my 828mkII allow one to change the gain stage on input channels. Again, I don’t know the 16A.

Thanks for the note back. My Eurorack is +4dB Line Level and the Digitakt says peak up to +22dB. What do you mean by +18 or +16dBu input levels... I was searching and couldn’t find those numbers. Isn’t Line Level standard +4dB? Are you saying that interfaces are expecting +16dB instead of +4dB Line Level now?

On the 16A manual it says input “up to +24dB” with a trim range of +2 to +24. Thanks!

[mikehalloran]

Right now, I’m using a Mackie mixer with a Combi-jack as a level matching preamp and it works quite well but takes up a lot of space for what I’m doing.

I have one of these on order to see how it works between my Yamaha P121 and my M4. I will also test it with my iPad. If it works well bot both, I’ll order another.

https://www.sweetwater.com/store/detail ... el-shifter

[HCMarkus]

Assuming your 16a is functioning properly, if your devices are running at +4 and not being padded down at some point internally or externally, and your cables are good, you should have plenty of gain.

How do the input levels look on your input meters?

Remember, there is an internal mixer between the inputs and your monitor chain. This can dramatically impact what you hear (or don't hear!)

[mikehalloran]

Or one can read the manual.

Good news: Turns out that, unlike the M4, the Line In is not fixed and has input trim in 1dB steps between +2 to +22 dBu. Now, time to read that manual and figure out how to do this.

https://cdn-data.motu.com/manuals/thund ... _Guide.pdf


1/4” Female, TRS
100 ohm
123 dB
-110 dB (0.0003%)
+0 -0.1 dB, 20 Hz/20 kHz +20 dBu
16 dB in 1 dB steps
Complies with EBU-R68 / SMPTE RP-155 1/4” Female, TRS
10 k ohm
117 dB
-110 dB (0.0003%)
+0 -0.1 dB, 20 Hz/20 kHz
+24 dBu
Trim range: 22 dB (+2 dBu to +24 dBu) in 1 dB steps
Complies with AES-11 2009 Annex B BNC
75 ohm (in/out)
44.1 kHz / 48 kHz, +- 0.5% 1vppto3vp-p (withtermination) 5.0 vpp, (2.5 v p-p terminated) complies with AES3-4-2009
Internal, universal 100Vto240V,50Hzor60Hz IEC 3-conductor receptacle
35 watts
Balanced, Tip hot
Per leg
A-weighted
-1 dBFS, Unweighted, 1 kHz Ref. 1 kHz
+4 dBu to +20 dBu
Balanced/Unbalanced, Tip hot
Compatible with: EBU-R68 , SMPTE RP-155 , +4 , -10 , 2vRMS , 1vRMS

If you still don’t have enough gain, you‘’ll need something to step it up. When I get my Ebsound unit, I’ll report back.