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Boss DR770

Drum Machine By Derek Johnson
Published July 1999

Boss DR770

A few years ago, dedicated drum machines seemed in danger of extinction — but now they seem to be undergoing something of a renaissance. Derek Johnson gets hands‑on with the latest addition to Boss's Dr. Rhythm range.

Once upon a time, every hi‑tech studio had a drum machine — and some had several. These days, of course, a drum machine is not an inevitable presence in a decently equipped studio, and it's not unusual for the average synth to offer huge selections of contemporary‑sounding drum voices derived from decent samples. The fact that synths (and samplers) can offer the right sounds, then, and that most hi‑tech musicians work with high‑powered sequencers on which creating drum patterns is simplicity itself — all this should have resulted in the demise of the beatbox, right?

Wrong. For some reason, the dedicated drum machine is still thriving: there are at least 10 models out there, and that's not counting the rash of grooveboxes which owe at least part of their existence to their percussive prowess. There must be something about the drum machine that makes it more than the sum of its sound‑generating and sequencing parts. For me, there certainly is. I've always had a drum machine around; I like bashing velocity‑sensitive pads (much more comfortable than synth keys), and I find that programming a drum machine makes me work differently than sequencing drums with a computer sequencer.

I chose a Boss DR660 as my drum machine a few years ago, swayed by its great sound set (which included enough 808 and 909 samples that I didn't feel too bad about having sold my original machines), sufficient editability, and the fact that, although it was quite reasonably priced, the 660 had two individual outputs as well as its stereo out. Lots of others must have felt the same way about the dinky 660 (reviewed in SOS January 1993), since it remained on Boss's catalogue for over five years — a long life indeed for a modern electronic instrument. And now there's a sequel, the equally dinky DR770 Dr Rhythm.

Skin Deep

The DR770's back panel: compared to its predecessor, the DR660, it gains a dual footswitch socket, but loses one of the older unit's two individual outputs.The DR770's back panel: compared to its predecessor, the DR660, it gains a dual footswitch socket, but loses one of the older unit's two individual outputs.

Blue and orange colour scheme aside, the DR770 comes in an almost identical package to the 660. Drum sounds are triggered from 16 velocity‑sensitive rubber pads that, courtesy of two switchable banks, can control 32 sounds, with 14‑voice polyphony. Banks can also be layered, so that each pad triggers two sounds simultaneously.

The 32 pad‑triggered sounds, plus 23 that can only be triggered over MIDI, make up a 'Kit'. There are 64 factory Kits on board, including 'normal' Kits, plus ambient, TR808, TR909, drum & bass, Indian, Brazilian and many other themed variants, and 64 memory slots for user Kits. The DR770 inherits the DR660's simple dual effects processor and adds a 2‑band EQ; their settings can be saved with a Kit.

From the photo, you'll see that the 770 has numerous buttons: these are all clearly labelled, which makes their functions fairly obvious and operation quite intuitive:

  • Song/Ptn: switches between Song and Pattern modes.
  • Real/Step: selects real‑ or step‑time record for Pattern creation.
  • Drum Kit: selects a Kit.
  • Pad: hides the editable pad parameters within a Kit.
  • Rev/Flang: assigns a variable amount of each effect to a pad.
  • Effects: accesses effect/EQ editing mode.
  • Utility: covers a selection of global parameters, including roll and flam functions, swing value, timing shift, footswitch assign and metronome level and value.
  • MIDI: hides the 770's few MIDI‑related parameters.
  • Flam/Roll: pressing this while hitting a pad causes a roll or flam to be input into a Pattern.
  • Tempo: alters tempo between 20 and 260bpm.

Dedicated Copy and Delete buttons are also provided, as are standard transport controls, and there's an alpha‑numeric keypad for inputting tempo values directly and selecting and/or naming Patterns, Songs and Kits. Some of the 770's buttons hide a parameter menu, which is scrolled through with cursor keys, with values changed by one of two large dials. The other dial changes overall volume.

The large display appears identical to the DR660's, but doesn't seem as bright as that on my DR660. Sadly, Boss have not added backlighting and there's no contrast control, which makes the small text sometimes shown in the display even harder to read — especially in low lighting (such as on stage).

The rear panel is the source of another disappointment: the main stereo output is augmented by only a single individual out, as opposed to the 660's pair. The second socket is still present, but is now a dual footswitch socket. Though I mourn the loss of the individual output, many potential 770 owners might find the footswitch socket a more useful facility, especially in a live situation; I know of one or two gigging types who went for Alesis's SR16 over the contemporaneous DR660 because of the SR16's footswitch‑controllable playback start/stop. Obviously, Boss weren't going to let that slip past them this time around! The socket is actually a stereo jack, allowing two footswitches to be used with a special splitter lead. One is assigned to stop/start duties, while the second can trigger a pad sound (allowing you to bang a bass drum with your foot, like a real drummer), step through fills and variation Patterns, reset the current Pattern and enter record mode. Actually, this makes me wonder why Boss didn't also make the individual audio out a stereo jack, providing access to two outs with an audio splitter lead.

A Peek Inside

Though the 770 is operationally similar to the 660, sonically it's a case of all change: there are still 255 raw waveforms, the same as on the DR660, but the 770's set has been thoroughly revamped. It takes up twice as much ROM — the result, claim Boss, of new, higher‑quality samples with more bottom end. Kicks (52 of these), snares (67), hi‑hats (19), toms (32) and cymbals (17) still abound, and there are those obligatory samples from the 808 and 909, including new cymbals, but there's slightly more in the way of Latin and 'world' percussion on the new machine, which is good news. The main additions are three typical tabla hits, open and mute surdo, and high and low versions of timbales and cuica, rather than just one of each. The bass sound complement has been doubled to four — TB303, slap, fingered and acoustic — which gives the 770 a bit more scope in a limited studio setup, or on stage to assist a solo performer.

All the 770's clean, well‑recorded sounds can be edited to a reasonable extent: they can be tuned over two octaves up or down (in 10 cent steps), decays can be lengthened or shortened, and volume and pan can be changed. More interesting is the Nuance parameter, which successfully emulates the effect of a drum or cymbal being hit at different places on its virtual striking surface, courtesy of a little trickery and filtering. This parameter also works on the acoustic bass sound, giving the effect of a filter change, but not on the other basses, strangely.

Some elements of a real‑world kit physically can't be played at the same time — such as open and closed hi‑hats — so the DR770 lets the user incline towards authenticity by defining sounds which won't play when a linked sound is playing, with seven sets of 'exclusive' assignments. It's also possible to define how multiple drum hits will respond — for example, whether repeat hits of a given sound will cause each subsequent hit to cut off. For some rolls, a more natural result is produced if a sound is allowed to play for its full length, avoiding the familiar 'machine‑gun' effect. Each pad can also be assigned a velocity curve, giving a variety of velocity responses. It's here that pad bank layering becomes a useful facility: using the crossfade velocity curves, the sounds in layered pad banks can be set to play at different velocities.

The Rhythm Method

Though I wouldn't buy a drum machine for its preset patterns — I never use them — those looking for instant rhythm could do a lot worse than the DR770. It houses 400 well‑programmed, if slightly tame, Patterns covering a wide range of styles, from straightforward rock and ballad to Latin and up‑to‑date dance idioms (jungle, hip‑hop and techno are all here). The attempts at 'world beat' styles fall a little flat, in my opinion; the Indian and Afro Patterns aren't quite what you'd expect, with the former being more '60s/'70s raga rock or jazz fusion than bhangra or Bollywood, and the latter feeling more Latin than African. Still, with 100 styles and 400 Patterns to wade through there's a good chance of finding something appropriate, and preset Patterns can be customised if copied to a user memory first. The new 'Quick Search' function saves time by allowing Patterns to be searched by category. This idea may be borrowed from various synths whose sound sets can be searched in a similar way.

Alongside the 400 preset Patterns is space for 400 user Patterns. When creating a Pattern, the user has several options. First, choose a drum Kit. Then decide whether to record in step or real time, set Pattern length (maximum 80 steps), and define a quantise value of between a half and a 32nd note, by way of quarter‑note, quarter triplet, eighth‑note, eighth triplet, 16th note and 16th triplet values. Quantising can be turned off, but there's no post‑quantise option, so a sloppily‑played Pattern can't be tightened up with quantisation later.

If you've chosen real‑time recording it's simply a matter of pressing the Record button in the transport section and playing along with the metronome as the Pattern loops. Bum notes (and entire Patterns) can be erased with the Delete button, individuasteps can be edited (by changing their voice or altering their velocity), and parts can be shifted backwards or forwards in time (to 'push' a snare drum part, for example).

Step recording uses a simple event‑type list, with the user choosing a resolution for each step. The options are the same as for real‑time record, which means that an event could be inserted on each 96th subdivision of a beat! As you step through a Pattern, pad hits, complete with velocity, are stored at each step. Sadly, the DR770 follows in the 660's footsteps and doesn't offer grid‑based step recording, the justly popular drum‑programming method pioneered by the TR808 and TR909 and implemented in some way by most other grooveboxes out there.

Once you've created a selection of related Patterns, they can be chained into a Song; there are 100 on board, each with up to 250 steps. As well as being created by manual chaining, Songs can be recorded with the new DPP — Direct Pattern Play — function. This assigns Patterns to the pads for real‑time triggering in any order. It's a feature that might have been inspired by the groovebox instruments, which place a lot of emphasis on composition on the fly and always allow pattern triggering of this kind. Sadly, there's only one DPP set on board, though the user can edit it at any time.

The neat Real‑time Pattern Change facility of the DR660 is also present on the 770: preset Patterns are arranged in groups of four, making 100 'Styles' consisting of the Original Pattern, a Fill to Variation, a Variation, and a Fill to Original. When a Pattern is playing, pressing the fast forward button starts the Fill to Variation Pattern, followed by the Variation, and pressing rewind plays the Fill to Original, before returning to the Original. The manual suggests you organise your own Patterns in a similar fashion so they can be used in the same way.

Last Judgement

Summing up the DR770 in one sentence is simple: it's a no‑nonsense, all‑purpose beatbox that sounds great and is easy to use. I have no major problems with this machine at this price, though the display, being less bright than my 660's, can be hard to read. Small wishes include a tempo track to record tempo changes over a Song — but when sync'ed to MIDI clock the 770 responds to tempo changes and Song Position Pointers, so this isn't critical. I do find it a bummer that the 770 (as the 660) always thinks in terms of quarter‑note beats, so 7/8 or 11/16 time signatures aren't possible (except by working out your song over multiple quarter‑note‑based Patterns). And if I'd had to choose between 'better quality drum samples' and 'more drum samples', given the high quality of the original DR660 sound set I might have gone for 'more' — though there is a noticeable and welcome kick to these new samples. I found some of the 808 and 909 sounds to be a little unsatisfactory compared to those on offer in my 660, though manipulating the various parameters (especially Nuance) helped to get them closer to my idea of what those older machines sounded like. My last gripe is that preset Pattern memories can't be overwritten. In fairness, though, 400 user Patterns is rather a lot, and once they're full the memory contents can be dumped over MIDI.

Boss's enhancements for the 770 are very worthwhile, notably the extra user Patterns, user Kits and Song steps, and the nifty DPP. The new sound set may not seem all that big a deal, but side by side with my DR660 the DR770 does sound bigger and heavier. Add to that a simple but useful 2‑band EQ, and you have a formula for success. On the face of it, the DR770 is simply more — in many cases, much more — of the same, but in the DR660 Boss produced such a cute, covetable and successful formula that they've obviously seen no point in reinventing this particular wheel.

DR770 Features

  • 255 drum and percussion sounds.
  • 64 preset, 64 user Kits.
  • 14‑voice polyphony.
  • 400 preset, 400 user Patterns.
  • 100 Songs; 250 Patterns a Song; 10,000 Patterns between all Songs.
  • 96ppqn resolution.
  • 20‑260bpm tempo range.
  • Reverb, flange and 2‑band EQ.
  • Dual footswitch socket.
  • Stereo output plus one assignable output.
  • MIDI In and Out.

The Big M

Even if you're devoted to programming rhythms with your drum machine, there may be times when you need to use it as a sound source in a wider MIDI system. In this situation the 770 can sync, or be sync'ed to, MIDI clock (supporting Song Position Pointers), and will function as an admirable percussion sound expander. As noted in the main body, a Kit not only includes the 32 sounds that can be triggered from the pads, but also 23 sounds triggerable over MIDI. The DR770 won't respond to pitch‑bend, however, and a mod wheel is useless with no modulation parameters. It also won't respond to aftertouch, and this lack of real‑time control means that some of the promise offered by the new 'world' percussion samples will remain unfulfilled. For example, much of the characteristic sound of tablas comes from the way performers work their hands on the drum head, which can be simulated with samples if their pitch and/or filter settings can be manipulated in real time over MIDI. This can't be done with the DR770.

In the opposite direction, the DR770 can trigger external sounds: this will be on the machine's global MIDI channel, but it's possible for a pad with no sound assigned to it to transmit a MIDI note event. So, at a pinch, and given Kits with the right MIDI note numbers assigned to the pads, the DR770 could function as a simple sequencer.

Processed Beats: The Effects

The DR770's effects are the same as the 660's, except that the reverb and flange effects are augmented by a global 2‑band EQ, which is perfect for beefing up an already solid bottom end.

Simplicity is the watchword: the reverb processor offers hall, room, and plate variants plus delay or pan‑delay, while the flange processor offers chorus or flange. All have the most basic set of editable parameters: in the case of reverb, simply reverb time and low‑pass filter. The delays have a feedback parameter, while the chorus and flange have depth, rate, feedback and delay parameters. It's worth noting that assigning any pad in a Kit to the individual output causes the reverb to become unavailable to any other pad's sound. Basically, you can have an individual output or the reverb in use at one time, not both. The DR660 had a similar shortcoming, and it's a bit sad, in my opinion.

The Ambience feature provides a short‑cut to effects for the lazy, offering 16 preset effects/EQ configurations ranging from Low Boost and Hi‑Fi to Garage, Club and Stadium. These immediately and quite noticeably alter the character of a Kit, and also make it easy to change effects and EQ settings for a whole Kit at once. Though an Ambience configuration can't be edited, the effects it lends to a Kit can be edited once they're in place, and those edits saved with the Kit.


  • Plenty of high‑quality sounds covering most purposes.
  • Lots of room for user Kits and Patterns.
  • Just enough in the way of sound editability.
  • DPP is a good way of creating on‑the‑fly performances.
  • Easy to use.


  • Only one individual output, and using it puts the reverb out of action.
  • Display rather dim; backlighting would be much better.
  • Effects quite basic.
  • No MIDI real‑time control over sounds.


The DR770 doesn't, perhaps, offer as much potential for weirdness as many people are looking for these days, but it's a great all‑round beatbox that looks set to have as long a life as its forebear, the DR660.