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Rockman IIB & Ultralight

Portable Amp designed by Tom Scholz

Rockman IIB and Ultralight.

The original Rockman amp. which has been available for some time now, has been used by many reputable artists, such as Jan Hammer, Carlos Santana, Al DiMeola and Allan Holdsworth as well as by the designer Tom Scholz (guitarist in and leader of Boston). The idea behind the unit was to provide the performer (be it guitarist or keyboard player) with the sort of sound normally only available in the studio or from a collection of signal processors and amplification special features. However, the original unit, whilst producing a great sound, had certain problems with noise and unwanted distortion. In the Rockman IIB and the Ultralight models particular attention has been paid to these problems.

For those of you who are not already familiar with the Rockman, it is a black plastic box 6.2" high, 4.2" wide and 1.4" deep — about the size of a Walkman — and can be worn on the belt in a similar manner. It also comes with a pair of collapsible headphones of extremely high quality. It runs on eight AA size batteries (which is no mean investment) which give a useful working life of around 35 hours. All the controls but one are located on the top where they can be accessed easily whilst playing. The sole exception to this is an overall gain preset, which is located on the back where it cannot be knocked out of position. This should be set at the best level for the equipment through which the output is going (be it headphones, amp, mixing desk or record player).


On the top there are 4 small slider switches, two inputs and two outputs. First we have an on/off switch, with an LED which flashes to let you know that the unit is on (presumably the flashing is designed to minimize battery wastage). Above this is the volume switch, with three positions, maximum, -5dB and -10dB. This is particularly handy for fast changes of level in a 'live' situation as a rotary control in this position (at the hip) would be less manageable. To the right of this is a mono ¼" jack socket labelled 'Guit Kybrd Input' and it is here that you plugin the instrument whose sound you want to treat. Clearly the unit is primarily designed for guitarists but the keyboards we put through it sounded interesting and different, the effects working best on aggressive lead synth sounds (no wonder Jan Hammer likes this little box).

So what effects do you actually get? There are two more switches, one marked 'Echo Off', 'Normal' and 'Chorus Off' and one marked 'Dist', 'Edge' and 'Clean 1' & '2'. Unlike most effects boxes, the 'Normal' position doesn't mean that the signal is untreated. As the idea behind the box is to get that 'stage' sound, this is exactly what this position gives you. This sound is achieved by a subtle chorus effect combined with a moderate amount of echo. Neither of these effects are in anyway adjustable, but this is not the aim of this unit. The idea is to create an ambient sound, such as one might achieve by careful adjusting of a series of signal processors or by use of a 'live' room in a studio, and to have this instantly and permanently available. It is this big sound which is the beauty of the Rockman, and it seems impossible to get this from such a small box. You can turn one or the other effect off — it is vital to be able to turn the chorus off to tune up for example, but if you want a clean signal you should use the other input.

The last switch changes the actual sound. Firstly, there are two 'clean' settings. Clean 1 is a sharp sound, ideal for clean, fast rhythm playing, whilst Clean 2 is a more full, more rounded sound, typical of the sound a jazz guitarist might use, and is particularly effective with the chorus on.

Now we move on to the 'meatier' sounds. 'Edge' (which is a new setting not on the original Rockman) is an extremely handy one. Tickle the strings and you get a lovely clear sound, ideal for arpeggios and spread chords, but hit the strings harder, for chords or lead lines, and it pushes the Rockman into a soft, rounded distortion, giving a nice chunky chord sound or a cutting lead 'edge' (hence the name of this setting). But the last setting is the real triumph. 'Dist(ortion)' brings in an extra circuit which turns the 'edge' distortion into the hard clipped variety, giving a rich harmonic content to the sound. Add in the echo to this and you get the sort of guitar sound you normally only hear on record or from a big stage using a stack of amplification and processing. This setting really makes your guitar sing. The sustain just seems to go on and on.

Close up of control functions.


Using the Rockman on headphones is almost a surreal experience. The sense of space is almost disturbing — it is difficult to believe that you are not in a huge acoustic chamber, or that the other people in the room are not sharing the experience. This, of course, comes from the fact that the 'normal' setting contains a specially regulated amount of echo and chorus. The reason that these are not variable is that they have been fixed at the optimum levels to obtain this 'ambient' feel. It is, of course, most convenient to use the Rockman on headphones, but with a lead terminating in a stereo mini-jack, the output can be taken to an amplifier, a mixing desk or your home stereo, making the Rockman useful for anything from the live 'gig', through studio sessions to the amateur home player, all with that 'big' professional sound.

The other clean input (which we have hardly mentioned yet) is also a big bonus for the home user. It enables them to play their radio, record or cassette player through the Rockman and monitor both the music and the guitar accompaniment, all without disturbing the people sharing the same room or house. For the amateur user this must be one of the major advantages of the unit.

The internal configuration of the Rockman is well thought out, and neatly laid out on 2 fibreglass PCBs. The system utilises TL072 op amps which is one of the main reasons why these models are so much quieter than the original Rockman. The echo and chorus are based around MN3011 and MN3007 bucket brigade delay lines.

The principle difference between the IIB and the Ultralight is that the latter has no echo available. However, the space is empty on an identical circuit board, and Dixie's Music assure us that all Rockmans (the original or the Ultralight) can be upgraded to the IIB specification for the difference in price between the original unit and the cost of a IIB, so you can go for the lower price model and upgrade when the extra money becomes available. The Ultralight, for example, is £66 cheaper than the IIB.


The price of the IIB is £245 (RRP inc. VAT) which may seem expensive for a unit with four basic sounds on it. The publicity material says "you would need 10,000 dollars worth of studio gear to duplicate the Rockman sound", which may well be true (although you could do a lot more with such gear). What is certainly true is that you would need to spend a lot on amplification and processors and what is perhaps more important, a lot longer setting it all up, to have the sound which is available at the flick of a switch cup the Rockman. All you have to do is sort out the right leads and connections and you can have that 'big' sound virtually anywhere.

The Rockman is distributed in the UK by Dixie's Music, (Contact Details).

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HH K150 Keyboard Combo

Electronics & Music Maker - Copyright: Music Maker Publications (UK), Future Publishing.


Electronics & Music Maker - Oct 1983

Review by Paul Wiffen

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