Ok, let’s clear some things first. What’s our goal? To get a sound as close to a tube amp as possible. But why do we do that? We probably have played or listened to a tube amp with the volume cranked up and know the feeling so we have agreed that’s what we’re after. And the amps’ manufacturers have made it really easy for us to do that. Setting the preamp’s gain where we like it, adjusting the EQ a bit and then finally cranking up that master volume! Problem is that we try to emulate that with a whole different setup (e.g. modeler / audio interface / active speakers) and there are many parameters that affect our signal flow. Let’s check some of these parameters in our signal flow that affect our signal both EQwise and Volumewise.
- Guitar: This should be set at the volume we usually play but keep in mind that changing things in the signal flow will result in different “behavior” from the guitar’s volume as the dynamics change. It’s a subtle difference though.
- Modeler Input: This is what we actually refer to as impedance. Modern devices usually have an impedance adjuster (or different input) in order to receive instrument level or line level. Instrument level is the default option but if you use specific pedals before the modeler or if you have active pickups, consider the other available options. Another thing to keep in mind is the analog-to-digital conversion (and the opposite) that happens with digital equipment as this also alters your sound although newer digital equipment have become incredibly transparent.
- Modeler Preamp: This is designed to behave like the preamp of an amp. Crank the gain up and you’ll get saturation. Adjust the EQ and you’ll get the same adjustment as when you do so in a preamp. Be really careful with the preamp’s volume though. Cranking the preamp volume too much will give you a much hotter signal that usual, resulting in cracks, pops, audio peaks and generally bad sound. Usually an amp’s preamp doesn’t get to that point. The preamp’s master volume doesn’t go to… unnecessary loud territories, but the amp sims nowadays give you that option.
- Modeler Power Amp: The latest modern modelers have separated their amp sims to preamp and power amp, giving you options for both. A power amp sim usually tries to emulate the tubes used and what we call bias. The power amp sims usually don’t have a volume. Why is that? Because in this signal flow this is not where your power amp volume actually is. Cranking the power amp sim volume would not be as cranking an amp’s power amp volume.
- IR (modeler): We all like to use plug n’ play stuff, don’t we? Well, by deciding to go that road we have to be careful though. An Impulse Response is a .wav file that substantially alters your signal’s EQ, trying to emulate the speaker’s characteristics when captured by a mic. Before going down the rabbit hole, I’d just like to point out that the IR plays a major part to your final sound, so putting the right volume to it is crucial. Not all IRs are the same volumewise, and they shouldn’t be the same so keep that in mind and check if your modeler has volume, high pass and low pass options for that.
- Modeler Master: Before thinking that this is my power amp volume, it’s not. The modeler, and all of its controls, is actually your preamp in this signal chain and even though it might give options to adjust the sound like a power amp would (many power amps have controls like presence, resonance etc), it does not do the power amp’s actual job, which is driving the speakers!
- Audio Interface Input: The audio interface takes your analog signal (whether you used a preamp or not) and converts it to digital so it can be edited and stored to your computer. Cranking the gain of the audio interface’s inputs will add color to your signal as this is actually another preamp (Wait, WHAT? But I already have a power amp sim in my signal flow, how did I go back to preamp? Well go back to Modeler Power Amp section then and read again) Setting the audio interface’s input levels as low as possible would let you avoid that coloration but remember that its analog-to-digital converters will alter your signal no matter what. As with the Modeler Input, check the impedance options of your audio interface input as well.
- Plugin Amp Sim: If you don’t use a modeler device, then all the steps before the audio interface don’t interest you. Well, except the guitar obviously. Your signal is not preamped until it gets to your audio interface (which as mentioned, has its own preamps) and the plugin. So these two are what compose your preamp now.
- IR (plugin): Instead of putting the Impulse Response in your modeler, you can also put it as a plugin. This moves the IR in the signal chain and may have a slight or huge difference depending on your other choices. For example, if you need to crank the volume of the audio interface because you don’t have enough volume otherwise, the differences will be bigger. It’s a bit like putting a booster before or after the drive.
- Audio Interface Master: Even though this might look like it’s your power amp, it’s not! The master volume of your audio interface raises the volume of your signal flow in overall. It’s the most “transparent” change you can make in order to give more volume to your sound without altering your signal flow, so do that before adjusting anything else before it!
- Nearfield (Active) Speakers: That’s your power amp, right there. The volume of your nearfield (or FRFR) speakers is what drives them and that’s what happens with a tube amp connected to a cab as well. Driving the speakers will give you that full sound and that room feeling you only get when in front of a speaker. Of course that doesn’t mean that you should go and max that up! (You wouldn’t do that to a tube amp now, would you??). Setting the speaker’s level at 0-4db is usually best as it is best for recording and mixing purposes but how about cranking that up instead and see the result. You might want to test it to see if it would give you a better live sound but don’t expect it to work with every model. If it does, congratulations you have a better sound than before! If it doesn’t, set it to appropriate levels and go crank your audio interface master, or whatever is last in your signal chain.
These are the most frequent parameters in your signal flow when trying to get that tube sound without a cab. It doesn’t mean that a person has all these parameters in his signal flow as everyone’s setup is different. This... rumbling was written down so the modeler and amp sim users out there understand the many "spots" in your signal flow that alter your tone (either drastically or not).
Conclusion: Freak out? Of course not! Understanding your equipment and some audio stuff enables you to make the best out of it by making the right adjustments. Do what you have to do and keep playing, no matter what!
Check out our FREE Custom IR Pack designed to to emulate the Live sound of a cab!