How to Build a LIVE Software Rig
Part 2

How do you make a laptop or tablet reliable?

In Part 1, we look at how to make a software rig rugged enough for gigging. In Part 2, we'll focus on making it reliable.

A small rack case and industrial velcro is all that's needed to make a laptop rugged enough for transporting to venues. To really be ready for gigging, the hardware and software must also be reliable. We need to think about possible failure points and create a backup plan.

First step is to do what you can to reduce the risk of failure in the first place. Audio interfaces are often just as rugged and reliable as any other piece of studio equipment, so failure is no more likely than with a guitar pedal.

A laptop on the other hand requires some extra consideration. When using a laptop in an environment with loud music there is some risk associated with the hard drive. If your laptop has a magnetic drive, you must replace it with a solid state drive (SSD). Luckily, SSDs are becoming more and more common on laptops and within a few years magnetic drives will be obsolete. Any laptop that has hard drive RPMs in it's specs (e.g. 5400 or 7200 rpm) uses magnetic storage with fragile moving parts and must be substituted. A magnetic drive is very sensitive to bumps and vibration. The bass frequencies alone from a loud band can cause damage. SSDs are made entirely of memory chips that do not have these vulnerabilities. Tablets will always have an SSD.

Your laptop really should be a dedicated part of your gear, and not be used for other general purpose activities, such as Internet access. There are guides on the Internet for tweaking a Windows or Mac OS for low-latency audio use, but since that is slightly different for each OS it is beyond the scope of this article. Often, the manufacturer of your audio interface will have a guide for OS audio performance procedures. If not, use Google to search for audio optimizations for your specfic OS. As a quick overview, start with a fresh install of the OS and install only the minimum software you need. Disable all networking, and wireless interfaces. Use USB keys to transfer new software, settings, etc. Never connect it to the Internet. Do not apply software or security updates unless absolutely required (if it's never connected to the Internet, security is not a big concern). Keep in mind that you will configure a live rig for the lowest possible latency, while for recording and mixing you use high latency.

A laptop that is never connected to the internet, has a solid state hard drive, and only the necessary audio software installed will boot and be ready to play very quickly (under 30 seconds) and will shutdown even faster. I have been using the same laptop every week with my band for 2 years now and never had a single crash during a performance or had to reboot.

You should still have a backup plan in case of problems.

From pub gigs to band rehearsal, in the unlikely event of computer failure you want to be able to finish the show. To me, this means you can keep playing your instrument, and the audience can still hear you play. This can be as simple as getting the sound properly to the PA mixer. A passive DI box fits easily in your gig bag, and in an emergency lets you get sound directly to the mixer. If a clean tone is unacceptable, maybe a single distortion pedal will suffice. The goal here is to keep it as simple as possible so you can switch quickly and don't waste effort packing unnecessary gear for something that may never happen.

If you play small venues like coffee shops and don't use a PA, even if you are using digital effects modelling with a real amp at the end of the signal chain, in the event of a failure, you've at least got that basic amp. Just crank the gain on the preamp and adjust the volume to get some distortion if totally clean won't do. I'll get into a little more on how to combine digital models with real amps later in the article.

If you are playing a high profile show as a professional paid musician, such as a wedding, festival, or playing a tour venue, then you might need a redundant backup. In this scenario, a second identical laptop and audio interface is ideal (with the same software installed). If something dies, you can hook up the backup unit and be running again in less than a minute. Rather than be upset by the brief interruption, the venue promoter/client will be impressed with your professionalism.

The most important thing for any gig where the audience has come specifically to the venue, rather than to see you specifically, is to keep the venue promoter happy.

As much as we want to showcase our unique and amazing musical talents, it's your professionalism that a venue promoter is likely to remember. Once the basic requirements of appropriate musical genre and musicianship are met, promoters are far more interested in how you conduct yourselves. How fast and unobtrusively can you setup and tear down? Do you keep fiddling with changing sound levels all night? How long are the gaps between your songs? If a piece of gear failed, how short was the downtime?

With a rugged and reliable software rig, the advantages at the beginning of this article contribute positively to increased professionalism that will get noticed by venue promoters.

The final component of our software rig involves getting the sound from the audio interface to everybody's ears.

You need to consider how to get the sound to you, and how to get it to your audience.

The best way to use a software rig is to send the line-out of your audio interface directly to the PA mixer, or optionally to a powered stage monitor, then daisy chain out to the mixer. This gives you maximum versatility, and minimizes the amount of gear you haul, particularly if the venue provides monitors. It also gives the best control over stage volume.

However, if you are not using a PA, you and your audience will probably hear your sound from one and the same speaker, on or near the stage.

A coffee shop or small pub is a typical example of this where you aren't using a general purpose PA, and each musician would normally rely on their own amp as the only source of their sound. In this situation, you can still connect the line-out from your audio interface to the line-in on a general purpose PA speaker, or floor monitor. When using a full-range speaker like this, you probably want to include a model of a guitar cabinet in your software rig otherwise there will be too many highs present in the sound. An acoustic amp also qualifies as a full-range speaker when using its line-level input.

However, if you don't own a full-range speaker, you can also use a regular guitar amp if it is connected correctly. Unfortunately you cannot plug the line-out from your audio interface directly into the guitar input on your amp for several reasons. Since instrument levels (from a guitar or pedal) are lower than line-level (audio interface outputs), the line-out will likely distort the amplifier instrument input in an unpleasant way. If you really want to send a line-level signal into an instrument input, you need convert the signal level and impedance. This can be done with a 'reamp box'. A common trick is to use a passive DI box in reverse but this is not ideal and can cause other issues. But more than that, by using the guitar input directly you've put another guitar preamp and cabinet at the end of the signal chain! If you are only modelling effects in the software, this might be okay, but if you are using a digital amp and cabinet, sending the sound through a second real preamp and cabinet probably won't sound very good.

(LEFT) The ideal way to use a software rig is to connect your audio interface directly to the PA mixer, or a powered floor monitor. (RIGHT) In the studio, 'Reamp'ing is used to take a recorded performance of a clean guitar track, then play it back, sending the audio through a conventional pedal chain and amp which is then re-recorded by mic'ing the amp. While this does work for putting some digitally modelled effects at the front of the chain in a Live rig, you'll get far better versatility using the 'FX Loop' method if you don't have a PA or powered monitor.

The best way to use a real guitar amp with your digital models is to use the FX loop.

Anyone who has tried their real pedals in the FX loop may have been disappointed with the sound. This is because FX loops are designed to work at line-level since they come after the preamp stage and before the power amp stage. This means FX loops were intended to be used with rack effects that operate at line-level, not guitar pedals that operate at instrument level.

(LEFT) Instrument level is a range of low voltage and high impedance unbalanced connections between guitars, pedals and amp inputs. Not good for long cable runs. (CENTER) Mic level is another low-voltage signal, but is usually balanced and has low output impedance allowing it to be connected to low impedance inputs. This allows mic cables to run long distances with good signal quality. (RIGHT) Line level is the standard for patching sound to and from mixers and rack effects. It can run long distances and be passively split into two more copies if required.

A Blackaddr Audio microMIDI MK I foot controller is used to control the rig. The laptop is only slid out and opened to power it on and power it off, otherwise it remains closed and tucked away inside the rack. Aside from the NanoPOG mounted inside the rack, all bass and guitar effects, amps and cabinets are modelled entirely in software.

MIDI foot controllers come in a wide range of prices and sizes. Typically you use them to change between software presets in your virtual rig, and also to toggle effects mid-song (e.g. engage a booster for the solo). Keep in mind you do not need a switch for every effect in your virtual rig. By using presets, (say one per song) you only need one switch per effect change during the song. Effects that stay on or off the entire song are enabled or disabled by the preset in your software.

The programmable controller shown here uses push-button rotary knobs to provide extra switches. The total of 5 switches, and 3 knobs is capable of moving between presets, changing effects mid-song, and tweaking things like volume, gain, etc. Since MIDI permits multiple effects to change with a single button push, you really don't need a dozen foot switches.

Sign up for our newsletter to be notified of new articles and blog posts