Calibrating Input Level for Plugins

Yep, I did the same a few weeks ago, the value is -12db for the SPDIF output to get Helix values (11.5 dBu).

While the input of the AxeFx may be 17.5dBu, the digital output from SPDIF does not keep the same value.

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Ok, so I guess @TheTrueZoltan! selected the output as SPDIF source as well when doing the measurement... if you select input 1 it will be indeed around 17.5 dBu and a +6dB needed to match the Helix
 
*Might* not be a great idea, it really depends. If when the gain is at zero and you have a sufficiently loud signal that is well above the noisefloor floor, you’ll have an easier time calibrating from a known value than having to work out how much gain is added. It’s certainly an issue on a noisy Behringer that records a very quiet signal at minimum settings. I suspect your MOTU isn’t as noisy?

The Motu is in fact doing pretty well in terms of noisefloor - so that might not be a sufficient reason on its own to go through all that. But as we've discussed before, it's also annoying to permanently run into waveform display issues, so I'm solving two issues at once.

Yes, the Pro-FS does have a 1MOhm Hi-Z input.

Let me add that the old Babyfaces had a Hi-Z input as well, but it was coming with a 470kOhm impedance, so defenitely not ideal for most ampsim applications. Too bad because otherwise they're still most excellent interfaces, possibly with quite some years of driver support to come, and they can be had for as little as €250-300. Yes, you need to connect the breakout cable for many things, but the good thing for us guitar players would be that the instrument in is located on the main unit, so it'd be a great mobile companion. If only the impedance wasn't at 470k...
 
now we have ola twisting himself in knots, thinking he should be turning his signal up above clipping 🤦🏻‍♂️
 

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Does anyone know the reference value for mixwave plugins? (Milkman Creamer and Benson Chimera) Their support didn't give me an exact value.
 
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But does he know why? 😁

He seems to think it's to prevent clipping.
At the end of the day, if that's how he gets his tones, it's not wrong at all.

He may not care for the "why" at all which is fair game for somebody who has the amount of gear he has at hand & only uses plugins / digital stuff when travelling or for scratchpad / writing purposes.
 
I smell a lot of oportunism in his video. I think there´s no need to state such a cutting "you all are wrong", especially when he had to make an effort to find a situation where the "pot at minimum" method causes noise.

Actually, from a practical point of view, is him who is wrong. It´s not practic at all to need to measure the headroom each time you tweak the input gain pot. Even if you only measured it once, it´s a sh...y solution, because if you move the pot, then you have to come back "approximatelly", by eye, to the right spot each time you want to use your plugins (or measure it again instead). And at the end... all of that just for a couple dBs that doesn´t even solve the noise issue (I experienced it myself with a Zoom AMS-22).

Clearly, the best way of doing it is with the pot at minimum, even if it implies using a non-rubbish interface (almost any interface) to avoid noise issues.

To sum up... it´s him who is wrong.

He just wanted to enter the game and get some attention (and managed to do it).
 
In an ideal world, you'd measure all the guitars you're using and set your input trim so even the hottest pickup in them wouldn't cause any clipping on your input. That'd optimize the noise floor.
Only after that would you do the measurements and adjustments suggested in this thread to make your plugins sounding as intended.

Keeping the input trim of your interface at zero is not exactly good general advice. Yes, it's possibly the quickest way to get convincing results (along with the Google sheet and what not), but as it defenitely ignores noise floor issues, it's not the best way. Add to this that you may as well run into waveform display issues.
 
Keeping the input trim of your interface at zero is not exactly good general advice. Yes, it's possibly the quickest way to get convincing results (along with the Google sheet and what not), but as it defenitely ignores noise floor issues, it's not the best way. Add to this that you may as well run into waveform display issues.
Chicken and egg stuff, but the point is most manufacturers these days are already spec’ing gain at 0 to be JUST enough room for loud pickups.

That’s why it’s already pretty well optimised for gain at 0, and why many do it simply because any kind of boost from there would cause clipping.

Yes there are of course exceptions, but there is a reason that as general advice it will be fine for many. The Behringer is an outlier on 2 fronts because it is significantly noisier than most designs, and it has a very low level at 0 gain (although some others have -3dBu of headroom at 0 gain which is barely anything and you have to pad).

It just backs up what @Sedaxel said above where some interfaces just aren’t well designed for a guitar interface.
 
Yes there are of course exceptions, but there is a reason that as general advice it will be fine for many.

Don't get me wrong, it's fine for me, too. But still, as mentioned several times, waveform displays are driving me mad all the time. Yes, I know it's partially Logic's fault as well, but I could certainly do with a little more input gain (which is why I am now kinda switching to a little 5dB input trim boost, even if adjusting it each time I transport my stuff, is annoying).
 
Don't get me wrong, it's fine for me, too. But still, as mentioned several times, waveform displays are driving me mad all the time. Yes, I know it's partially Logic's fault as well, but I could certainly do with a little more input gain (which is why I am now kinda switching to a little 5dB input trim boost, even if adjusting it each time I transport my stuff, is annoying).
Yeah, Logic’s waveform view is just another factor though that doesn’t really have any bearing on calibration or SNR really. Easy enough to reach a position that satisfies all 3 of your needs though, I think with the motu it’s basically solved aside from having to recalibrate your gain knob every so often
 
I smell a lot of oportunism in his video. I think there´s no need to state such a cutting "you all are wrong", especially when he had to make an effort to find a situation where the "pot at minimum" method causes noise.

Actually, from a practical point of view, is him who is wrong. It´s not practic at all to need to measure the headroom each time you tweak the input gain pot. Even if you only measured it once, it´s a sh...y solution, because if you move the pot, then you have to come back "approximatelly", by eye, to the right spot each time you want to use your plugins (or measure it again instead). And at the end... all of that just for a couple dBs that doesn´t even solve the noise issue (I experienced it myself with a Zoom AMS-22).

Clearly, the best way of doing it is with the pot at minimum, even if it implies using a non-rubbish interface (almost any interface) to avoid noise issues.

To sum up... it´s him who is wrong.

He just wanted to enter the game and get some attention (and managed to do it).
There are very few people who seem to grasp the situation from top to bottom, and you nailed it
 
In an ideal world, you'd measure all the guitars you're using and set your input trim so even the hottest pickup in them wouldn't cause any clipping on your input. That'd optimize the noise floor.
Only after that would you do the measurements and adjustments suggested in this thread to make your plugins sounding as intended.

Keeping the input trim of your interface at zero is not exactly good general advice. Yes, it's possibly the quickest way to get convincing results (along with the Google sheet and what not), but as it defenitely ignores noise floor issues, it's not the best way. Add to this that you may as well run into waveform display issues.
I mean in theory yeah I could test each guitar and have a spreadsheet of safe headroom and then each time I swap my guitars I could remember to adjust the interface…. And then reference that and offset each plugin I’m using

But the reality is the rme ucxii im using on +13dbu is about right/perfect for 2x BKP pickup sets. The fishman fluence moderns internally clip around +10/11dBu so bit of room there. Balaguer pickups, stock Gibson SG and Strat pickups are where things are lower are where you’d even consider doing some form of SnR optimisation. Never once have I thought this kind of thing was an issue. I’m all for doing things that yield free gains but all things considered juggling numbers and offsets is really introducing more variables into the mix which can lead to confusion down the line pulling up sessions (wait was this recorded with the offset or was it done right…. I’m only human these things happen).

It’s all contextual I guess. For someone who has one or two guitars that are low output and if their interface was a bad performer, then SnR optimisation would make complete sense.
 
I couldn´t care less about how the waveforms look in my DAW, honestly. I don´t think that´s a problem that should affect the discussion (sorry Sascha, no offense intended).

The discussion is about accuracy of the sims and noise. Both subjects are perfectly addressed with the "pot at minimum" approach and a normal audio interface (95% of currently marketed ones... even a Presonus Audiobox Go will work just fine). With a very noisy interface, it probably wouldn´t work anyway with the other approach.

I don´t understand the need of seeing a problem where there´s no one.

And if sims accuracy isn´t important to anyone, just tweak the interface to taste.
 
I mean in theory yeah I could test each guitar and have a spreadsheet of safe headroom and then each time I swap my guitars I could remember to adjust the interface…. And then reference that and offset each plugin I’m using

Nah, I thought more about measuring the hottest guitar-pickup-boostpedal arrangement you'd possibly ever come up with.
I was doing that some days ago (well, just very briefly) and found that I could still raise the input gain of my Motu M2 by a good handful of dBs without running into any clipping.
As said before, my noise floor most likely won't profit much (the Motu is doing way better than the Behringer in the guy's video), but the waveform display defenitely will. Not too sure whether I will go that way, though, because it'd require setting the input trim each time I unpack the Motu (which atm would be daily), so just turning the knob all the way down defenitely is the easier solution.

Irrelevant sidenote: Add to all this that at least at home I will very likely return to a permanently set up hardware (or rather hybrid) solution, as in shaping anything minus spatial FX (and perhaps cabs) before the signal hits the interface. Thing is, while I'm getting pretty much phenomenal plugin performance with the M3 MB Air at just 3.5ms RTL, I noticed very clearly that I'll likely become a victim of option paralysis again. Which, fwiw, is also why I just stopped using NAM profiles for a while already. It's simple been like "hm, maybe I can still find something better at ToneHunt" too often. I know, I could just resist - but I simply can't (curiosity, "wow"-factor and all that...), so limiting myself the hard way seems to be a decent idea, keeping the plugin thing for my mobile needs only. Let alone I'd still have more options than to poke a stick at using hardware.
 
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