Hello and welcome to this Sound On Sound podcast. I'm Paul White, and this time I'll be talking about getting the best from guitar amp modelling plug-ins. 

There are several excellent guitar amp modelling plug-ins from which to choose, but in order to get the best out of any of them, you first need to consider a few factors. I know that some guitarists avoid modelling plug-ins altogether, as they don't feel that they get the same sound as when standing in front of an amplifier, and that's only natural. The key point here is that when you're evaluating the sound, you should perhaps be referencing what you would hear back in the control room when micing an amp in a different room, not the sound you get from standing in front of a lowered amplifier. They'll never be the same.

Before you even decide on which amp modeling software to use, you need to find the best way to get a good guitar signal into your DAW. As you may know already, guitars fitted with passive pickups work best when fed into a fairly high input impedance and a standard line level input doesn't have a high input impedance, so amp Although you will still get a signal, it's likely to sound rather lifeless. Some audio interfaces have a high impedance or high Z instrument input option, so if your interface has that feature, then start by using that.

If your interface doesn't have a high impedance option, don't worry as you may be able to use a guitar pedal as a high input impedance stage. Most pedals, when active, will present the guitar with a suitably high input impedance, but those that have a buffered bypass mode, such as those made by BOSS, also have a high input impedance when in bypass mode. So, if you have a pedal with a buffered bypass but don't want to use the effect, switch the pedal to bypass mode, put it between your guitar and the line input of your audio interface, and you have a buffer.

If your budget will stretch to it, a dedicated buffer pedal may be even better. And if you can get one that also has some basic EQ, it might allow you more flexibility in fine tuning your sound.

It's also worth thinking about which guitar cable to use. There's a lot of smoke and mirrors talk in the world of cables, but your guitar lead actually can have a very significant effect on your tone and that's because the cable capacitance is significant enough to affect the way that your pickups sound. As a rule, low capacitance cables produce a brighter sound and higher capacitance cables a warmer sound. The cable capacitance can also affect the resonant peak of your pickups, so if you have a few different guitar leads to try, then check them all and see what sounds best, because there is no right or wrong, it's just whatever works for you.

The raw signal from a DI'd guitar can have a very spiky attack, as you can confirm by checking in the waveform view of your DAW. It can help the model's sound if you can tame these spikes before the signal hits your audio interface. One option is to use a compressor or limiter pedal with a fast attack time, actually before the input to your interface, and a little compression will also improve the general feel of the instrument. 

There's another great and inexpensive trick which was passed on to us by Sound On Sound author Craig Anderton. He suggests putting a pair of red LEDs in parallel across your guitar lead. The LEDs are wired in opposite polarity and the idea is that when the signal gets high enough, the LEDs start to conduct and give you a kind of soft clipping effect. If you can experiment with different makes of red LED, not all have the same clipping characteristics so you might find that some are better than others.

All DAW recording systems that rely on native plug-ins for processing introduce some latency, but in order to feel comfortable when you play, this has to be kept as low as possible. That means setting the smallest buffer size that you can, while still keeping your system stable.

However, buffer size isn't the only cause of latency. If you have other tracks playing that are being processed by plugins that introduce a long processing delay, such as a linear phase EQ or some plug-in that uses impulse responses, then the latency may still be too high. The answer is to temporarily disable the offending plug-ins when you're recording, or, if you're a Logic Pro user, use the low latency button to do this for you automatically.

If you still can't get the latency low enough, consider using your interface's direct input monitoring facility to add some immediacy to the sound. This will mix in some of the unprocessed input sound, which may make you feel more comfortable even though the combined direct monitoring sound added to the amp model plug-in sound might seem a little odd. But don't worry, this won't affect the sound that you actually record.

Yet another option is to split your guitar signal so that you monitor via a small amplifier and record the clean signal at the same time. One of these little desktop tuning amplifiers, or practice amplifiers, is fine for that purpose. A more exotic alternative is to use one of the Universal Audio Apollo interfaces, which allows you to monitor directly through a UA amp simulator plug-in hosted by the interface itself, so as to avoid latency. 

Note that while a typical guitar amp has two gain controls, usually a preamp drive and a master volume,  cranking the input gain of a model amplifier will bring in more simulated preamp distortion, as it would with a real thing, while turning up the simulated master volume replicates the sound of the output stage being driven harder. However, it isn't always a good idea to max out the level feeding into your amp emulation plugin, as they don't all respond kindly to very high input levels. Take a little time to experiment so that you can find the sweet spot where you get the best sound. Start by aiming for a signal hovering around the minus 10 dB full scale mark at the input to the amp model plug-in that's placed before the guitar amp emulation plug-in.

While an amp modeling package may also include effects, many of them do, there's still an argument for using some of your own pedals between the guitar and the interface. I've already mentioned using a compressor to help tame the peaks and also to keep the level more consistent, but you may also get a better result by using your own overdrive pedals. As a rule, amp modeling software is good at clean sounds and it can also produce credible heavy rock distortion. But some struggle to replicate those lively, touch sensitive, on the edge sounds. That's where a good analogue overdrive pedal can help. It can also help to use a compressor in combination with lower amounts of overdrive to get the necessary sustain. Again, don't be tempted to push the input to the amp model too hard.

Another useful tip offered by Sound On Sound's Dave Lockwood is to use an overdrive pedal, but with the drive turned up and the guitar volume turned fairly well down so as to produce just a moderate amount of distortion. This can often give better touch sensitivity than many amp sims are able to offer on their own. 

Other pedals can influence the way you play, such as wah wah pedals, so these are often best used as you record, rather than adding afterwards as emulations. Even so, there is an advantage in using some software effects, such as delays and reverbs, as that will help to keep things sound natural if you need to do any editing. If you were to use delay or reverb pedals up front and then you need to make an edit, the delay and reverb tails probably won't flow naturally across the edit point.

When searching for a sound it's tempting to step through all the available amplifier setups and accept them as they are, but in my experience the amplifier model is only half of the solution and even then the factory presets would probably need tweaking to match your guitar and your playing style just as a real amp would. 

The other 50 percent of the equation comes from the speaker cabinet that the amplifier is paired with. It often pays to try out different speaker cabinet emulations until you find a combination of amplifier and cabinet that gives you the sound that you want. If you have the option for changing the virtual mic position, that can also help to fine tune the sound.

You don't have to stick with the speaker emulations offered by your amp modeling software. You can switch off the emulation section and then try different IR based speaker emulation plug-ins, such as those from Two Notes or Celestion. You can also use third party speaker impulses in some speaker cabinet emulators, so it's worth trying those too. 

If you're one of those players who never uses reverb when performing live, you might feel like you should carry over the same practice to recording. However, this can result in an unnaturally dry sound, unless the cabinet miking options include adding room mics. The reason for this is that a close mic'd guitar cabinet excludes much of the room ambience, whereas in live performance you always hear some room ambience due to the acoustics of the venue or studio. You don't need to add any obvious reverb to make your recording sound natural, but by choosing a room ambience setting, you can dial in just a little sense of space without making anything sound reverby. If a bit of reverb helps you to actually play better but you don't need it on the final recording then why not use a room simulator or reverb plug-in to give you the right vibe when you're playing because you can always remove it or load up a less obvious emulation when mixing. 

For those looking to create ambient or abstract guitar sounds you might find that you don't always need an amp emulator. Sometimes just using a clean DI sound combined with the effects such as delay, reverb and pitch shifting can get you where you need to be. That's the beauty of the electric guitar, the sound can be whatever you want it to be. There is really no one right sound. 

And finally, don't forget to try the amp emulations on other sources too. They can work really well on keyboard, drums and even vocals. Well, that's all for now and thanks for listening.

Thank you for listening, and be sure to check out the show notes page for this episode, where you'll find further information, along with web links and details of all the other episodes. Oh, and just before you go, let me point you to the soundonsound.com/podcasts website page, where you can explore what's playing on our other channels.