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Boss JS5 JamStation

Backing Sequencer
Published February 2001

Boss JS5 JamStation

With its host of programmable backing patterns and an audio track for live recording, the Boss JamStation is designed to enliven the tedium of solo practice, or provide an instant sketchpad for ideas. Nicholas Rowland strikes out on his own...

Nothing is more boring than practising an instrument alone. And even the most dedicated bedroom musician will agree that you learn faster and are much more creative when working with other musicians (furthermore, there's always the possibility that someone else will get the drinks in down the pub afterwards).

The Concept

The JamStation's audio input is switchable between guitar, line‑level and mic‑level sources — a footswitch can be used for remote control of start, stop and cycle.The JamStation's audio input is switchable between guitar, line‑level and mic‑level sources — a footswitch can be used for remote control of start, stop and cycle.

Over the years, there have been several stand‑alone hardware 'band‑in‑a‑box' units designed to improve the lot of the solitary musician by providing a group of virtual backing musicians. While they may not buy the beer, they at least stop and start when you tell them. The Boss JS5 Jamstation is just such a device — a four‑part, auto‑accompaniment 'backing generator' to give it its full description. But the JS5 adds a significant new twist in the form of a digital audio track that enables you to record vocals or guitar alongside the auto‑accompaniment patterns. More importantly, this track boasts an automatic time‑stretching facility, which means that you can change the tempo of the song and the audio elements will keep pace accordingly (without changing pitch, naturally). As well as backing and composition duties, this means that the JS5 can also find employment as a phrase trainer — allowing you to record in your favourite Allan Holdsworth guitar licks, slow them down to manageable speed and then learn how to rip them off big time [surely 'use them as a starting point for your own work?' — Ed].

Connections & Storage

In physical terms, the JS5 is a neat unit — slightly larger than a video cassette case — with a clearly laid‑out front panel that makes it easy to use, even if you can't be bothered to read the manual properly. Connections comprise MIDI In and Out, Left/Mono and Right outputs on quarter‑inch jacks, a mini‑jack Headphone socket, an input for one or two footswitches and a recording input which is switchable for guitar, microphone or line. This mono input works in audio‑through mode — in other words the external instrument is merged with the JS5's output (handy when you're working with a practice amp that has only one input...). On the side of the unit is a slot for a SmartMedia card, onto which you can save audio tracks and song data once the onboard memory is full. You'll need to budget for at least one card as, in its unexpanded state, the JS5 offers a paltry one minute and 35 seconds of recording time in its so‑called 'Hi‑fi' mode. You can squeeze another 23 seconds out of it by switching to the other 'long recording' mode, but even so, it doesn't give you much to play with. The good news is that because they have become very much the standard for digital camera storage, SmartMedia cards are now relatively inexpensive. A 32Mb card will give you 34 minutes of recording time (27 in Hi‑fi mode) while a 64Mb card gives you just over 68 minutes (54 in Hi‑fi). To be honest, I didn't notice any wildly significant quality difference between the two modes, and considering that the JS5 will be mainly used as a scratchpad for ideas, I should imagine that most users will go for length over quality.


The accompaniment section offers 200 preset songs, 100 user song locations and the facility to store up to 100 more user songs on each SmartMedia card (regardless of the card's overall capacity). Note that storing song data does cut down on the maximum audio recording times. The basic building blocks of songs are a Style and a chord progression, plus data such as tempo, voice assignments and part mix parameters. While you can't record audio alongside a preset song, you can copy a preset to a user location and then work with that. Each style is made up of an Intro, Ending, two Verses, two Fills and two Breaks, the JS5 collective noun for these being 'Forms'. The 200 preset styles cover the usual auto‑accompaniment territory, with three banks of Rock and one each of Pop, Ballad, Blues, R&B, Jazz, Fusion, Dance, Latin, Country and World. Programming‑wise, it's all pretty competent, especially in the Rock, Pop and Blues areas. Like many auto‑accompaniment devices, where the JS5 tends to be weakest is with styles such as House and Techno, though this is unlikely to bother most of the JS5's potential purchasers. Certainly if you're an aspiring Van Halen, BB King, or Carlos Santana, you'll find the JS5 fun to jam along with.

Each pattern consists of four parts – drums, bass, and two melodic voices — with control over mute, volume, pan, reverb, chorus and insert effects sends and voice assignments. The JS5's 128 melodic voices and 16 drum kits sound pretty good, being particularly strong in the bass and guitar departments. I was surprised to find that the soundset didn't follow the usual GM/GS pattern — a bonus in my book, though not so good for anyone hoping to use the JS5 as an external module to play back prerecorded MIDI files. While sounds can't be programmed, there's a lot you can do with the effects section, which offers reverb, chorus and inserts effects busses. There are no less than 40 insert effects types, and like the choruses and reverbs they are extensively programmable. The bad news is that effects cannot be used on the audio track, which is surely where they are likely to be needed most. D'oh and double D'oh!

<h3>Song Patterns & Audio Recording</h3>

Easy is definitely the word for the JS5's EZ song‑creation mode. You simply tap in what style, chord progression template, tempo and key you want and — bingo! — there's your basic song. Then it's a question of recording the sequence of verses, fills and so on, which can be done in real or step time. The JS5 has 26 chord types to play with, which is more than enough for most purposes. During playback, the LCD displays which chord is currently playing, which is great when you're attempting to improvise to a preset song. If you want to program your own accompaniment patterns from scratch, though, you have to plug in a MIDI keyboard or guitar — there's no facility for doing this from the front panel. Happily, you can use the JS5 as a four‑part expander in a sequencer setup. Apart from the non‑GM mapping of the melodic voices, most of its MIDI spec follows the GM/GS standard, so it should be easy to use for the technically challenged.

Recording audio tracks is again pretty straightforward. Arming the track displays a bar‑graph input meter for setting the levels from the external device and also gives you control over precisely which measures you want to record over. This feature is essential for making the most of your available memory and also means that you can go back and replace dodgy sections with new takes.

I have to confess that I wasn't expecting that much from the time‑stretching — after all, a facility like this can be dodgy even on top‑notch samplers. But I was pretty impressed. For example, vocals remained fairly coherent — well, as coherent as my vocals ever are — up to 40bpm either side of the tempo they were originally recorded at. Guitar riffs and solo runs also remained pretty much intact over a wide range, although with chords played on acoustic guitar there was a noticeable chorusing effect as soon as the tempo deviated by more than about 10bpm from the original value. However, I don't see this as a real problem. What soon became clear about the JS5 is that it's a great tool for songwriters, particularly if you want to try out a basic idea at different tempos with completely different backing arrangements. While it can be quite disconcerting to hear a song that was conceived as Van Halen meets the Sex Pistols to come back at you as Bluegrass or a freeform jazz experience in 5/4, it can give you a useful new perspective on your music.

As its full title suggests, the JamStation is also great for practice. One useful feature here is the ability to loop sections within songs, so that, for example, you can concentrate on soloing over just the verse or just the middle eight. In that respect alone, the JS5 is a fun tool to have around. But its audio track and particularly its time‑stretching facility really does raise its potential as a composition tool. If you're an anti‑social singer/songwriter who's had one musical difference too many, this could be the band you've been looking for!

JS5 Highlights

  • Polyphony: 32 voices.
  • Instruments: 128 melodic voices, 16 drum kits.
  • Programmable effects: Reverb (eight types), Chorus, Insert effects (40).
  • Styles: 200 presets, 20 user programmable.
  • Songs: 200 preset, 100 user, maximum 999 measures per song.
  • Chord progression templates: 26 user.
  • Max recording times: One minute 58 seconds internal, 33 minutes 59 seconds with 32Mb SmartMedia card, 68 minutes five seconds with 64Mb card.
  • Built‑in time‑stretch.
  • Assignable footswitch for start/stop or loop control.
  • Switchable input for guitar, line and mic.


  • Easy to use.
  • Time‑stretch is impressive given the price.
  • Presets are well‑programmed.
  • Decent sounds.


  • Limited recording time.
  • No effects on the audio.
  • External device needed to create own patterns.


The first hardware 'band in a box' to offer audio recording. Although the format has its limitations, the JS5 makes an excellent songwriters tool, enabling you to get basic ideas down and then try them out with different arrangements and tempos.