Roland's DJ70 is the third unit to make use of their current sampling technology, the others being the excellent S770 and S750. If you read the SOS reviews of those two products you will have been left in no doubt as to their sonic excellence. I propose to give only a brief resumé of Roland's sampling architecture; potential purchasers of an S770/750 sampler would be well advised to get hold of the October '91 issue of SOS where the subject was covered in more detail. I will, however, spend some time highlighting the differences between the operation of the S750/770 and the DJ70, which are significant. Oh yes, and there is also the 6" diameter turntable "to enable with each sampled sound the classic 'scratch' effect", as the manual puts it. We'll see about that later...

BUILT FOR SPEED

The DJ70 is a 3-octave keyboard sampler sexily housed in heavy, high-impact plastic finished in semi-matt dark grey, giving the unit a chunky look and feel. This baby is built for speed, with a very sensible control surface. At the top is a blue backlit LCD not unlike that found on the S750, the main difference being that this time Roland have remembered to put a shilling in the meter; it glows reassuringly brightly. Which is just as well, since it has to cope with reflections from the shiny clear plastic plate which stretches most of the way across the unit. Alongside the LCD is the ubiquitous alpha dial (a rather sticky example of the genre), and a pair of input peak level indicators.

Between this panel and the keyboard lie all the switches, broadly grouped in two rows, together with (input) sampling level, and (output) volume pots.

Below the alpha dial lies a diamond shaped cursor array. The other buttons, which are of an excellent size and feel very positive, are either square or rectangular. To the left of the keyboard is the standard Roland bender control, to the right the scratch wheel, above which there is a recess for up to four floppies to be neatly stacked ready for use. The integral 3.5" drive is housed below the scratch wheel, and is accessed from the front. To the right there is a stereo headphone socket and associated volume pot. Bringing up the rear we have an on/off switch, an IEC mains socket, an LCD contrast control (with an unaccountably sluggish response), sustain pedal jack, the three wise MIDI ports, left and right audio outputs, input sensitivity, and left and right audio inputs. All audio i/o is via quarter-inch jacks.

The major functions have hard or soft keys; other functions require item selection on the LCD using the diamond cursor array. Parameter values are entered using either the + and - buttons (which double as Execute), or via the alpha dial.

SAMPLING

I won't bore you with too much detail here. If you want that, go and read the S750 review referred to earlier. Instead, in order to give you a bit of a feel for the instrument, I will describe what happens when you switch it on.

From a standing start you will find yourself in Performance mode. Since there are no sounds in the machine yet, you will fairly rapidly want to get into sampling. Pressing the F5 soft key takes care of this. Now plug in your CD player and set input and sampling levels as per the manual.

New samples default to F4 (note) in the middle of the 3-octave keyboard (which, incidentally, can be 'virtually widened' via the Octave Up/Down buttons). Other default values are well chosen, such as: (sample) Time (4.5s, which is enough for two bars at 120bpm), Trig(ger mode — use the Start/Stop button); and (loop) Type (1-way = forward looping). If you are looking to grab a bar or so from a record, you merely have to decide whether you wish to take a mono or stereo sample. Then press Ready. You are now looking at the incoming signal level. Adjust the Sampling Level. Hit the Start/Stop button once to commence sampling, at the start of the desired bar of music, and hit it once again at the end of that bar to terminate. Congratulations — you have just created a looped sample which will repeatedly play for as long as a key is depressed, or indefinitely if Hold is activated. So simple, and so good. And there's more...

At Sample level (see 'DJ70 Architecture' box) the sound is laid over the entire keyboard, so triggering your sample at F5 will play it at twice the tempo of F4. Now hear this: by exiting from Sample level directly back into Performance (the smartest route is by pressing Play), you will now find that the sample you have just recorded has been given a Patch (and therefore also a Partial) of its own. The Patch will have been automatically assigned to the first available white key on the keyboard (starting at C3) and tuned so as to preserve the original pitch in this new location.

Repeated sampling in this way creates a series of Patches stacked onto the white keys, all playing back at their original pitches. From the Performance Play pages you can edit these Patches in the usual ways, including via the invaluable Patch Map page, which enables editing of the same parameter for all of the (up to) 31 patches simultaneously.

Pages 1, 2 and 3 of these edit pages are new on the DJ70. There are 16 Patches visible simultaneously (17-31 can be accessed with a single keystroke).

Page 1 looks like this:

etc...

Spit (split) enables you to change the Patch in that 'slot'. Mode gives you access to basic sample loop parameters (very handy). Pad refers to the eight pads on the DJ70 which are available, in addition to the 37 keys, as sample triggers. The Patch assigned to pad H is also the one on the scratch wheel. The '%' parameter can take integer values from +/-15 inclusive, and is designed to simulate the speed control on a record turntable. The Mem parameter is only important if you want to get into load-while-play (memory cache A can play while B loads from floppy).

Page 2 is an easy one, and goes like this:

etc...

Like I said, easy. Limits are self explanatory, Shift (in semitones) likewise. Kb is a patch-specific local off/on. On to Page 3:

etc...

The stereo mix parameters need no comment. Pb sets the pitch bend range (note that for Patch 1 in this example Pb is assigned to Volume), Bs stands for 'basic' MIDI channel: this can also be set 1-16 or off.

Sample editing facilities are equivalent to those of the S750. Here, in the forced absence of a TV monitor, use of the Graphic switch to toggle between the upper (text) half of the various edit windows and the waveform display below makes LCD editing relatively painless.

Creating Patches containing multiple Samples is likewise, as on the S750. Remember that if you want to make use of Roland's comprehensive envelope filters you will have to enter Partial level, and that by entering Edit Partial from a Patch, you have the option of manipulating all the latter's Partials simultaneously: indispensable when working with multisampled instruments.

SPECIAL FEATURES

The DJ70's non-latching Cue button mutes the stereo output and allows you to audition your next move. The DJ probably has a mixer which enables him to do that anyway, but I did find one area where the Cue function could be more than useful: if you put a loop into Hold play, then Cue auditioning does not mute the held loop, whereas muting on the mixer would cut out the loop.

Unlike the S770/750, the DJ70 sports an onboard sequencer, albeit a rather unusual one. The RPS (Realtime Phrase Sequencer) acts as a kind of MIDI 'window recorder'; a tape recorder is perhaps a good analogy. You can record eight 'phrases', which the DJ70 will replay exactly as you recorded; you cannot change tempo. You can trigger one-shot or looped playback of these phrases from keys on the DJ70 keyboard, and even record into a phrase a sequence that includes notes that trigger other phrases.

The Load While Play function works as follows. The RAM is divided into two caches, A and B, and you can vary how much memory is allocated to each. Loading into a zone deletes any samples which are currently loaded into it. So, if you don't want to lose anything, select Play, Page 1 (see above), and increase the amount of A memory until all the Bs and A/Bs have switched to A. Now load into B.

Time Stretch, as the manual so rightly says, is a crucial tool for the dance samplist. There are two parameters to consider here. Ratio, which can be set to any percentage between 25% and 400%, defines by how much the sample will be changed in length. Fade determines how smooth a result you will get: higher values mean better interpolation but longer waits while the DJ70 does its arithmetic. Auto is the ultimate smoothie, but can take "up to 100 times the length of the sample" to perform.

I tried both Manual and Auto stretches on a percussion loop. The default Manual settings gave by far the better result, and took only a few seconds. You can change the pitch of a sample by an (almost) exact number of semitones, since the ratio is complemented by a tuning scale indicator. You will have to retune your Patch or Partial by a similar and opposite amount, though, if you want playback at the original tempo and on the original key. In this way, musical loops and vocal samples can be made to fit in time and tune with your song; you can also use timestretch followed by re-tuning to generate vocal harmonies. It's probably a good idea to copy your sample before each stretch.

The last of the DJ70's special features is, of course, the Scratch turntable. See below for comments!

COMMENTS

The manual is by and large pretty good. There is, however, no alphabetical index, without which it might take some time to find a reference.

The exclusion of a TV monitor option (as on the S770/750) is noted but accepted. The LCD/control surface environment is almost as user friendly as the latters' mouse/monitor one. Without SCSI, though, I cannot see the DJ70 becoming the main sampler in a studio, where the single stereo output would prove to be yet another serious limitation.

The above criticisms could, however, be met with the answer "Well, that is not its intended use". Fair enough. I think criticism of the Scratch wheel is, however, rather more valid. The problem is that scratching a sample on the wheel is very different to doing the same on a turntable. Most worrisome is the delay between what the hand does and what the ear hears — it feels as though the sample is attached to the wheel by a rubber band. As our DJ put it: "it's a great idea, but the way it works is ****". Despite the fact that I have since found that wheel response can be improved somewhat by going into Patch Edit and turning the scratch sensitivity up to maximum, I would still say there is room for improvement.

While triggering on the fly is uniquely easy with this machine, using an automatic level threshold trigger (a not uncommon requirement) is slightly trickier than on the S770/750 for the following reason. In order to enter sampling you must press the Ready key. A second's-worth of number crunching ensues, whereupon the unit is primed. (At this stage the S750 offers another fast switch before it will commence sampling). What this means is that, if you are sampling from a sample CD, the CD player must be paused while you await the completion of the Ready routine. Not all sample CDs are so accommodating (see the X-static Goldmine review in last month's Sample Shop).

The sampling level meter gives no clear indication of when it's being driven-into the metaphorical red, a characteristic it shares with those on the other Roland samplers. One does get used to it, but surely a little software tweak would sort it out.

IN USE

I have, for the reasons outlined above, said that the DJ70 is an inappropriate core sampler for a studio, but for DJ's who want to get into sampling on the fly this has to be the first choice keyboard (I cannot comment on the current crop of DJ-oriented sampling mixers). It would also be a useful second sampler in a larger setup, as a complement to a first machine.

I can also see it in the role of a recorder — sampling and sorting live vocals should be easy, if you can work within the confines of the (rather meagre by today's standards) 4MB maximum memory. (Tip: use only HD disks. They store around twice as much information as the more common DD variety, and cost only a little more if you shop around. And get that extra 2MB of RAM in at once!)

CONCLUSION

The sonic performance of the DJ70 is not in doubt. It carries the same filters and bit manipulation that made the S770 my first choice sampler. Not having a hard drive or SCSI port, it can't be considered to be a very viable 'file based' sampling system, particularly as floppy disk management is primitive by the standards of some of the competition. Its forte would seem to be in the area of performance sampling, and here it is in a class of its own. The ability to load while playing, though welcome, is not revolutionary Ensoniq and, more recently, Akai, offer this. However, sampling, looping, and creating a multitimbral sonic palette suitable for dance-oriented composition could hardly be easier. This machine redefines the concept of 'user friendly sampling', and many of its operational niceties and default settings are bang on target. I bought the review model, and I have already astonished one or two colleagues with its childishly simple sampling routines. If you want to do it in real time, start saving, and get your order in now.

Further information

Roland DJ70 £1,799 inc VAT.

Roland UK, (Contact Details).