How do I correctly amp up the input gain when recording?

  • When I reamp, the DI can get correct levels on input. I just turn up clean sens and my DAW will capture it at a wanted loudness.. But the reamp is always stuck at -16db.. Can't seem to get it any higher unless I adjust RIG VOLUME. But is this the correct way of doing it to amp up the gain?

  • No that doesn't work. I always set my DAW at 0db gain. I need the hard input to match about -6db. I can't get it that high without having to adjust Rig Volume, and this feels wrong.. The reamp sens doesn't do anything. I maxed it and still it doesn't affect the input gain volume.

  • Ahh... OK, so you're only interested in the "physical level" entering the KPA and not the perceived amount of distortion; I get ya.


    There's no way to adjust this on the KPA. The first sentence of my response covered your only option:

    Firstly, adjust the level coming from your DAW to your satisfaction.

    You'll have to crank the DI-output level in your software's mixer. I can see no other option unless you want to place an additional physical booster in-line between your interface and KPA, something you might consider only as a last resort if all else fails.

  • Ah I see. Hmmm.. How are people really recording in studio with the Kemper if it's not possible to acheive this? A reamped track at -16db is way way too low.. My DI output level is already pretty high as it is. I am very interested in hearing how people are recording with the Kemper, and why it does not have a way of getting good signals out. I figure for that price tag, that would at least be a minimum?

  • Make sure the interface's output that you're using is set to "pro" / line level (+4dB).


    This is often able to be specified on a per-channel basis via the manufacturer's control software. It could be that the physical output you're using is set to "consumer" level (-10dB).

    How are people really recording in studio with the Kemper if it's not possible to acheive this?

    The pro line level I mentioned above is what's used "everywhere". At this level, with the ability to boost or attenuate the feed from your DAW, there's no reason why you should have any problem achieving the level you're after. In fact, if you maintain unity gain (no cut or boost to the signal) throughout the recording-and-playback process, the level reaching your KPA should be very close to ideal, and that's where Reamp Sens comes in, allowing you to tailor the distortion you hear to be as close as possible to what you heard from the Rig when tracking the DI output.

  • I am using mine with an old Focusrite Saffire interface and Logic. I have plenty of signal at all times. In fact I often reduce the SPDIF send for the DI to make sure I have plenty of headroom.


    As Nicky said, ot may be that ypur interface isn’t configured properly. Check the settings in its control software.


    If you really need to boost the signal going from Logic you can add the Gain plugin on the channel strip.


    When you say you are struggling to get -6db is this the return level of the reamped signal? That’s a pretty hot signal really. Many people recommend-18db to -12db per track to leave sufficient headroom on the master bus.

  • How do you guys fix this then? I have a pretty new Focusrite Clarett, and the input is set to 0db on all channel. I don't have this pro thing you guys are talking about


    Monkey_Man I am actually getting pretty hot signals when I am recording directly from the amp.. But when I am reamping, that's when the signals are very weak. Which I find very very strange

  • The only thing I can think of is you could try hooking the output you're using for the Kemper back up to an input on the interface and seeing what sort of level it's receiving when you send the DI track as you are now.


    This will at least tell you whether or not you're sending the signal to the Kemper at -16dB. If you're getting a similar level to what you believe it should be (-6dB), then the issue is not the interface or your DAW settings.


    That'd be a start in that it'd tell us where we should be looking.

  • I may be able to explain this.

    Short version: You’re using the unbalanced output of the Kemper (TS - tip-sleeve 1/4” jack) instead of the XLR (balanced) output (?). Take the XLR output into the balanced line input of your Focusrite and you should have unity gain through the system.


    Long version:

    Your DAW uses the dBFS (full-scale) meter scale, with 0dBFS at the very top of the meter. How analogue signals - measured in dBu - line up with dBFS varies depending on the operating level of the analogue equipment involved. This is what others are referring to regarding a pro +4dB operation mode. In real terms, this would mean that -20dBFS on your DAW meters would give you +4dBu in the analogue domain. This is a typical US operating level, and it is easier to think of it as ‘-24dBFS = 0dBu’. This can then be compared to the British standard -18dBFS = 0dBu. As equipment is sold all over the world, many manufacturers pitch somewhere in the middle if they don’t have adjustable operating levels. For example, your Focusrite unit appears to have a line up level of -22dBFS = 0dBu, looking at the specs.
    Now, you can consider these specs in the other direction as well, e.g. 0dBFS = +22dBu. This then tells you the (likely) maximum analogue signal level that the device can achieve before distorting. It may be able to go a little further, but this is your defined analogue clip point.

    If you look at the Kemper spec sheet, the operating level of the Kemper is also 0dBFS=22dBu (which is good news for you, as no further line up adjustment would be required in your system for unity gain). Shorthand is +22dBu, which is why the manual states “max output level: XLR +22 dBu”


    Significantly, you mention the -16dB value. This is the operating level if you only use the TS (Tip-Sleeve) jack output, which is unbalanced, the max output level is +16dBu. You will have balanced line inputs on your Focusrite Clarrett, so take the XLR output of the Kemper into one of those to reclaim your missing 6dB. The reason the TS is lower is because balanced signals comprise an in-phase and out-of-phase copy of the original signal on pins 2&3, in addition to the ground conductor on pin 1. The receiving differential amplifier measures the difference between the two signals (peak to trough of a waveform if it helps you visualise), which would be twice as great as one signal on its own when measured to ground (unbalanced). Essentially, you are halving the amount of voltage difference in the signal if you use the TS output vs XLR, and half the voltage equates to a 6dB reduction when metered. You should also consider that the interference picked up on the TS signal is rejected in the equivalent balanced signal, as it is the same on both the +ve and -ve cores of the cable, and therefore ignored by the differential amp.

    Hope this helps! Let me know if I’ve misunderstood your conundrum.

    Kind regards,

    Ed

    Ed / Audio Systems Engineer / Kemper Stage + Fender fan

    Edited once, last by EdwardArnold ().