Saturday, December 17, 2016

The Portable Guitarist—Amps, Cables and Connectors

The Portable Guitarist—Amps, Cables and Connectors

This series has so far explained the advantages of an iOS-based rig, the gear you need, transporting it, and setting it up for live performance.

This tutorial is about amplification options plus the relevant cables and connectors.

Mono In; Stereo Out

Look at the guitar lead—there’s usually a ring below the tip, indicating a MONO, or single signal lead. 

Two rings equals stereo—you’ve got the wrong lead. This is because a guitar produces a mono analogue signal. Consequently, all of the traditional gear that you’d plug a guitar into—pedals, amps and so on—come equipped with mono input sockets.

The iPad’s headphone socket, however, is a STEREO, or dual signal output. Furthermore, the output accepts an 1/8” (3.5mm) jack, whereas traditional guitar inputs accept an 1/4” (6.25mm) jack.

Simply put, the iPad produces too big a signal on too small a connector.

Thankfully, this can be overcome with the correct connections and leads. To make the right choice, however, you’ll need to decide what you’re plugging into: guitar amp, or PA (Public Address system).

Guitar Amp

Unless you own a stereo amp—such as the Roland Jazz Chorus, or run a two-amp set-up—you’ve the aforementioned stereo-into-mono problem. 

iPad to the Rescue

Luckily, an iPad can output in mono as well as stereo. To do this, go to Settings, and select General

Choose Accessibility, and scroll down to Hearing. You’ll find a slide button that activates Mono output. Try it through a mono cable into a single speaker; you’ll notice a louder, more detailed sound than when it’s in stereo mode.

Talking of cables…

Cable Conundrum

Online you’ll find any number of Y-cables that combine two mono signals into a single stereo signal. 

Search ‘stereo to mono cable’, however, and you’ll get a cable consisting of one stereo connection and two mono connections. You’ll struggle to find a cable that has a single connection at either end.

Thankfully, there’s some good news.

Adaptors

You can run a mono cable from a stereo output (the iPad) to a mono input (the amp). You’ll need a stereo 1/8” jack adaptor, however, on one end of the 1/4” guitar cable for the iPad’s headphone socket.

You can also use a 1/8” jack stereo cable, but you’ll need a stereo-to-mono 1/4” adaptor on one end to plug into the amp.

These adaptors cost just a few pounds, and are found easily on Amazon and eBay.

A robust—but more expensive—solution is the iLine Mono Output Adaptor from IK Multimedia, for under £25. For around £50, it comes as part of the larger and very useful iLine Mobile Music Cable Kit.

Front End, Effects Loop

If the amp has an effects loop, you could use the iPad purely as an effects unit using cables and connectors described above.

Some words of caution:

  • The amp’s overall output will be determined by the iPad, so you’ll need to turn that up
  • You’ll notice a level of noise that’s higher than when plugging into the front of the amp. You may not notice it when playing, but it’ll be there when you’re not. Whether you proceed will be determined by how loud the gig is, and how much noise you or your audience can take

I’d choose to plug into the front end, but this also presents issues:

  • Careful with the iPad’s volume; the louder you go, the harder you’ll drive the amp, which leads to distortion
  • Like any effects pedal, its position in the signal chain affects how it performs. An expansive reverb may sound fine on a clean sound, but could get messy with distortion

PA

When I started using an iPad live, I never used a guitar amp. Why use one amp, when apps provide the sounds of many? Instead, I used a PA. It presents some new challenges, but solves a lot of problems.

Stereo Compatibility

Unlike a guitar amp, a PA accepts an array of input sources and connections. Of interest here are line input jack sockets, which are typically stereo compatible. 

You could therefore connect your iPad with a 1/8” to 1/4” stereo cable. These are plentiful, and can be very cheap. Get the longest one you can, as you never know from gig to gig how far apart your equipment could be.

Double Up

Some line sockets accept stereo or mono jacks, so I run a 1/8” stereo Y-cable that terminates with two 1/4” mono jacks. 

Each of these plug into separate channels, as two preamps means more output. This lets me lower the iPad’s volume, giving a cleaner input signal.

Effects

Time-based effects like delay and reverb consume the iPad’s processing power. If your PA has inbuilt effects—that you like the sound of—employ them.

Mine or Yours

I arrange my PA like a traditional guitar amp stack, placed behind me. If you’re worried about getting sound out front, most PA units have a monitor output; simply run a lead from it to your band’s PA.

However, if you don’t own a PA, you’ll have to plug into your band’s one. If so, consider these points:

  • Your distance from the PA is the length of your lead
  • As cables lengthen, you run into capacitance issues, causing treble loss—the longer the cable, the more muffled you sound
  • If you can’t hear yourself then you need a powered monitor speaker

Conclusion

In the mono realm of guitarists, the stereo iPad can seem like a baffling choice, but you can make it work provided you:

  • Understand what’s mono and what’s stereo
  • Get the right cables and connectors
  • Choose your amplification wisely
  • A guitar amp’s front end is quieter than its effects loop
  • A PA has more options
  • Your own PA is easier than using your band’s

The next tutorial I'll explain the world of apps.


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