Reamping a guitar without a reamp box is definitely possible but could provide some additional challenges.
If you’re an owner of a recent audio interface, you can use an unbalanced output but you would need a splitter or a guitar pedal with multiple outputs in order to record guitar in the first place.
Using an older audio interface is far from ideal but still possible with the addition of a DIY or factory-made DI box. Reamping is also possible if you manage to get your hands on a guitar amplifier with balanced inputs. And the easiest way of reamping the guitar without a reamp box is to use digital amp emulation.
Let’s dig a little deeper.
Reamp box is a device that is used for converting a balanced line-level signal to an unbalanced high-impedance signal and vice versa. This basically means that reamp boxes serve to make guitar amps react to line-level signals as if it was directly connected guitar signal. The more advanced models let you split the signal and record both an amp and the direct input of the guitar.
How to use a reamp box
If you wish to record both a DI guitar signal and the amp, you need to connect your guitar directly into a reamp box, then send unbalanced output from the reamp box to the amp and balanced to your audio interface. Then it’s a matter of a very simple routing in your DAW. To reamp the guitar with a reamp box, you should send the DI guitar signal from your DAW to one of the DI outputs in your audio interface. Connect the output to the balanced input of your reamp box and send the unbalanced output to your amp. To simply put it, this is your best and the most reliable option to reamp a guitar and there’re plenty of very decent reamp boxes available on the market, but what should you do if your budget doesn’t allow it or if you’re simply in a hurry?
Reamping a guitar without a reamp box
Of course, using a dedicated reamp box although very useful and convenient isn’t really necessary, it’s just one of those things that makes your life easier, but there’re other ways of achieving your goal. You just need a bit of ingenuity to overcome some problems that might occur while you try to reamp a guitar without a reamp box.
Balanced and unbalanced signals differ in the number of conductors that carry the sound. Unbalanced cables have only two conductors and balanced have three conductors with an isolated ground loop which makes them less susceptible to RF interference. Furthermore, a balanced signal usually has reverse polarity in order to cancel out the noise and the devices that accept balanced signal switch polarity back. Usually, outputs of your audio interface are balanced and the guitar signal is unbalanced, which means that if you send your line-out directly into the amplifier, a quite noticeable amount of noise would be introduced.
Also, balanced and unbalanced signals have different impedance which means that they resist the flow of AC electrical current differently. Unbalanced signal has a significantly higher impedance than the balanced signal and if you try to send a balanced signal into a device that was designed to receive an unbalanced signal, you will get something that is called impedance mismatch. Depending on the situation, it can be completely unnoticeable, but usually, it has a rather audible effect. This effect might be represented by the addition of even more noise or by making the signal appear significantly weaker. However that may be when impedance mismatch occurs you could simply tell that your guitar just doesn’t sound right.
Using just audio interface
If you’re a happy owner of a modern audio interface, there is a pretty good chance that you don’t really need a reamp box at all. The latest generation of modern interfaces usually offers you both balanced and unbalanced outputs, which means that you can easily send a guitar DI signal to your amp. All that you have to do is route the guitar track output in your DAW to one of the line-outs and connect a TS output to it. Then it’s just a matter of putting the right mic in front of your amp and pressing the record button. Since you’re using an unbalanced signal with a proper cable, there wouldn’t be any issues with noise and impedance mismatching.
The only drawback of this method is that you actually need a way to record a DI guitar signal. A very simple splitter or a pedal with multiple outputs could easily help you with that.
Using older audio interface
If you use an older audio interface, reamping a guitar wouldn’t be as simple as that. Usually, older audio interfaces don’t have unbalanced outputs, which means that you may get some issues with noise and mismatching. But on the other hand, it’s very much possible that you would avoid them completely. In order to achieve the task, you need to make sure that the signal coming from your audio interface to the amp isn’t too hot because otherwise, it may get as far as burning down the circuitry in your amp. Start at the lowest volume possible and slowly increase it to the point where you’re happy with a result and your amp still can handle it.
Amps with balanced inputs
The simplest solution, of course, would be to upgrade your audio interface, but if for some reason you’re very attached to the old one, there’s another workaround. Essentially, you’re doing the exact same thing as described in the previous section, but instead of a regular guitar amplifier, you might use an amp with a separate balanced input. But the problem is that although guitar amps with direct line-out are pretty common, it’s extremely hard to find one with balanced input. And it’s even harder to imagine that you would spend any time searching for one, just for reamping with an old audio interface. The less time-consuming would be to look around your studio and search for a preamp with balanced input and unbalanced output or a guitar pedal with the same specifications.
We won’t bore you with technical details, but it’s good to know that matching the impedance is a matter of one very simple transformer, which means that you can make a DIY direct input box with a little bit of effort and research.
Using DI box
Whether you choose to build one yourself or purchase the DI box, it might also help you to reamp your guitar’s signal. The only problem is that DI boxes are designed to convert an unbalanced signal to a balanced one, but not backward. The transformer inside a passive DI box steps down the instrument’s impedance to the microphone level. So if you would choose to use it in reverse, which is required in our situation, this would mean that you would step up your signal significantly.
So, in theory, the signal coming from your audio interface to the amp would be way too hot. And this would be far from ideal unless you would find a way to reduce the level of your signal drastically before it would hit the DI box. And one last thing to remember is that a reamp box is actually a slightly upgraded DI box with additional features.
Using digital emulation
This might be a bit controversial, but in all actuality, the best way to reamp the guitar without a reamp box might be using some sort of a digital amp emulation. At least this is a more convenient way to do it since most modern audio interfaces have built-in DI boxes, which means that you don’t need additional equipment in order to record a proper DI guitar signal. Then it’s just a matter of choosing the right emulation of the right amplifier. The latest emulations are indistinguishable from the real amps when it comes to the sound, which means that you would have a lot more different amps to choose from and be able to adjust them as you please on the go. Where digital amps differ is in the feeling that they give you while playing and this shouldn’t be an issue since we’ve already recorded a guitar signal.
There’s no shred of doubt that a proper guitar tone is crucial, regardless of what type of project you are working on. The best way to ensure that your guitar sounds thick and juicy is to record a properly set amp with a good microphone. But things don’t always go our way and mistakes could be made at recording stages, you can try to fix them with EQs and compression, but eventually, you may realize that you need to reamp your guitar signal.