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Dynacord DRP15

Multi-effects Processor

Dynacord are probably best known in the UK for their samplers, but a careful look at the DRP15 suggests that we should be getting better acquainted with their effects processors. Wilf Smarties explains why.

Behringer. Roland. Atari. Yamaha. Neumann. Sennheiser. Sony. Steinberg. Names that make up the bulk of my own equipment inventory. Add in a few other key players — Akai, Alesis, Korg, Emu Systems, C-Lab, and Technics — and you pretty much have the dance market fitted out. Spot the British product?

And so on to another imported goodie, albeit a European one, stacking up against heavy American and Japanese competition: the Dynacord DRP15 Multi Effect Processor, a pro reverb and multi-effects unit that concentrates on quality rather than quantity. Obvious comparisons include the likes of the Lexicon PCM70 and Yamaha SPX900.


In fact, the DRP15 looks not unlike a cross between a PCM70 and an SPX900. It has the former's 'Soft Knob' data entry dial, with the latter's sleek dark profile, green backlit LCD and large LED program number display. In fact, familiarity seems to have been a prime design requirement. Lost the manual? Don't worry, it's very easy to drive the DRP15.

The dark grey 1U front panel has the input level potentiometer hard left. Immediately to its right, behind a clear perspex plate, lurk the following: a 2-colour 8-segment input level LED ladder, a 3-digit LED display, a 2x16 character LCD, a row of seven LEDs which show the current program architecture (see later), and a column of three status indicators (Edit, MIDI, and Eff Off — I found the latter amusing). Beyond that are two rows of three mode buttons, Edit, Config, Compare, Store, MIDI & Option. The rather cunning 2-speed soft knob for value entry, which doubles up as an Enter switch (you push it to select a value you've just dialed in), comes next, followed by four more buttons: Select+, Select-, Fact/User (memory banks), and Effect On/Off. Finally comes a mains power switch.

Looking to the back, from the left we have an IEC mains inlet, a ground lift switch, and three quarter-inch jack footswitch sockets (Pedal, Up/Down and Eff On/Off. The usual three MIDI ports are there, and the stereo outputs (switchable between Hi & Low) and inputs (switchable between Line and Instr) are all on unbalanced jacks. Signal to noise (effect on) is quoted at better than 90dB, processing is 24-bit, audio 16-bit linear, and frequency response (effect) 20-20,000Hz, +0/-2dB. Total harmonic distortion (effect) is a miniscule 0.03%.

The unit is of the usual mono in/stereo out format. A dry stereo signal can also be mixed in, though no-one will want to do that if they are working with a mixing console. Good news: the dry signal can be eliminated from all programs under the Options menu. Incidentally, while you are in there ask for the Last Edit to be remembered. Otherwise you will be faced with Factory Program 1 every time the unit is powered up. You can adjust the LCD contrast to suit a wide range of viewing angles.

The inclusion of a mono in/out and instrument level input makes sense, since some programs are definitely axe oriented — you can also use foot switches and pedals to select programs and change parameters.

There are 100 factory presets on board, together with 128 user memories, which come with effects pre-programmed. These are accessed by the Fact/User switch (for bank), and either the Soft Knob or Value Cursors. Depressing the Soft Knob installs the currently displayed program, and turning it while depressed (who isn't these days?) produces a tenfold increase in scrolling rate.


So how does the unit perform? First off, it should be noted that the DRP15 is primarily designed as a flagship reverberation unit. Its multi-effect capacities are not outstanding, though some of its non-reverb effects are certainly good. It must be judged on the quality of its reverberated sound and on its ease of use, the latter being of particular importance if it is going to find its way into professional recording studios and onto hire companies' books. From over a month of subjective use, I would say that it is at least as easy to program as a Yamaha processor, while its sound quality is much closer to that of the Lexicon PCM70.

The DRP15 is in general considerably quieter than the PCM70. It may not have some of that machine's more esoteric programming capabilities but, let's face it, who bothers to go into the registers and individually pan six early reflections anyway? It has most of the parameters you'll ever really want, (with the exception of reverb density, which is strangely only available on gated programs). Program auditioning and selection is an easy one-handed, one control operation, while all editing is quite logical. Get your Options organised before you start, and you're away.


The DRP15 can produce both single (eg. reverb, delay or pitch shift) effects, or multi-effects. When required to do one processing function only, the entire DSP chip is given over to that, thus maximising processing power and hence effect quality. Single effect algorithms are preceded by the letters HQ, indicating High Quality.

Constructing a sound from scratch (rather than editing a preset) starts with the Configuration (Dynacord-speak for algorithm) menu. You can choose from Direct Only, HQ Reverb, HQ Modulation, Pitch Shift, Long Delay, Delay + Reverb, Multi Effect, Pitch + Delay + Reverb, Instrument) Effect, or Delay Line 1 > 2, by rotating the Soft Knob, or using the Select Cursor. Once the

Configuration has been chosen, it's time to enter the Edit menu. Now the Select cursor toggles between parameters, and the soft knob adjusts values — again, depressing the knob as you turn it produces faster parameter changes.


Whatever the configuration, you always have EQ Hi and Low parameters to play with. This is a simple Baxendall bass and treble shelving equaliser. You might like to know that even with full treble boost (+14db) the output hiss was acceptably quiet. This is one reverb which shouldn't need muting in the mix.

There are two of operation: normal and 'easy'. In 'easy' mode some parameters are set automatically. This could be thought of as encouraging lazy engineers not to experiment, but I found it made for quick and effective operation in many circumstances. 'All Parameters' mode, however, is best for evaluating the reverb's editing potential. Most parameters will be familiar to most readers. HF and LF damping was very smooth, akin to that found on electromechanical devices such as EMT plates. Reverberation was extremely dense and smooth, again EMT-like, but much more controllable, with an almost uncanny lack of resonance or the metallic whines associated with lesser units.

Hall size goes all the way from 0.1 to 124,250 cubic metres (less in the case of smaller room programs). All settings produce a usable, clean result, though glitches occur while sweeping through from one size to another. Reverb time goes from 0.00 (quite a strange effect) to 20s: towards double figures looping becomes evident, though not annoying. In the real world of 0-6 seconds, reverb decay is pristine. The geometry of the reverberating space can take several shapes, though most sound quite similar to me. Reverb predelay can take values from 0 to 240ms.

All the usual early reflection algorithms are there, and a couple of interesting ones too — 'Expand' and 'Left > Right'. Scaling of the early reflections is dictated by Room Size. You can mix between reverb and ER, and can insert a delay between ER and reverb. The degree of programmability is pretty basic, but it is sensible, easy to use, and it hard to come up with an unusable result. The true 20k bandwidth shines through most of the preset programs, which sound very transparent.

Of the other reverb types I only want to mention Gated, since this is the only one to offer a completely new reverb architecture, a mono non-linear reverb. This is very clean, with a gate time variable between 10 and 340ms. Two other parameters, Slope and Color (yes, with the US spelling) affect the reverb envelope and density/length respectively. A negative slope gave a reverse reverb effect, while a positive one resulted in a normal gate. Color seemed to expand the reverb in much the same way as Room Size expanded Early Reflections previously: the longer the reverb the less dense it became. A maximum predelay of 200ms is possible, and the end point of the reverb envelope is soft rather than dramatic. Other units do this better.


Various Leslie, Chorus, Phasing and Flanging effects are offered. At safe settings most chorus units these days produce satisfactory results, and the DRP15 is no exception. I therefore decided to take some of the parameters to the limit to see what would happen. At maximum feedback (+/-99%) some units get out of control. Not this one. Many hard or modulated resonant effects are possible. For unmodulated effects, 95% seems to be the onset of ringing, but even modest modulation permits 99% feedback with no unpleasant side effects. Because of this, strong yet stable effects are possible, and while it would be a rich man indeed who could afford to tie up a whole DRP15 doing flanging in a mix, you could certainly lay down effected tracks or resample sounds with modulation applied. Hard static flanges (like the one used on Colin Angus' voice on 'Boss Drum') are easy to dial up.


The harmonising effect was smooth, particularly with downward shifts, and could offer a viable alternative to timestretching vocal samples. I noticed an appreciable sampling delay, however, and if you plan to use the HQ program on vocals in real time you'd better stick to thickening them rather than creating 3-part harmonies: the vocals would simply slip out of sync. I found that plosives and percussive consonants could sometimes produce glitches even on HQ shift: if all you are doing is retuning a sample, it would pay to take more than one transposed specimen, then pick the winner.

The DRP15 had problems dealing with drum loops. The smoothing algorithm of HQ Shift looks for a suitable crossover point between consecutive samples (much like an autoloop program does on a sampler). In doing so, samples of differing lengths are taken, knocking the rhythm for six. Here, the cruder 'Fast Shift' must be selected, whereby the harmonised signal picks up a hard flange, the frequency of which corresponds to the inverse of the fixed sample time. (By way of comparison, the SPX900 has a fixed sample time harmoniser only, but it takes more 'chops' or samples per second, and is slightly better at handling loops).

"First off, it should be noted that the DRP15 is primarily designed as a flagship reverberation unit."

While delving into the pitch shifter's programming I noted two bugs on the review model: two separate pitch shift lines are offered, and each is pannable between the L & R outputs. Panning left was fine, but panning hard right left the processed signal stranded somewhere near the middle of the stereo image. This was true for both channels of processing, and independent of whether the source fed into the left or right audio input. Also, pitch line 2 did not mirror the operation of 1, though they are designed to be identical: shifting in semitones sometimes resulted in level drops and unwanted modulation (other examples of the DRP15 do not show this fault, however).

My conclusion? I think there is a pretty good harmoniser in here just waiting to get out.


Under this configuration four delay types are offered: Mono; Stereo 1; Stereo 2; and Ping Pong. If you match delay time to your bpm, the Mono delay repeats on the beat, while Ping Pong alternates between left and right at twice that frequency. Stereo 1 has one side repeating on the beat, with the other side maintaining the same profile, advanced by 1/4 beat. Stereo 2 is similar to Stereo 1, except that the second delay line is advanced by one-third of a beat.

At 99% feedback, the signal decay took all morning. By the time I had made the toast, watered the cat, and put out the plants, the noise floor was only just beginning to creep up, while the audio signal still exhibited full bandwidth. The slowest repeat time possible is 57 bpm (around 1 second if you are still counting in old money).

I came across a couple of unexpected delay tricks — sweeping the time base produces analogue-type pitch shifting, just like in the good old days. And at smallish delay settings, Lexicon-type effects (resonant cascades) can be generated by a robust application of the Soft Knob. Hopefully you'll be able to record such real-time shenanigans over MIDI when the promised software revision arrives (see below)


The usual four delay options are offered, this time with reverberation. Only the 'on the beat' delays and initial signal are fed into the reverb process. The intermediate (left side) delays are left dry. I found this curious, and said as much to Dynacord, who are considering offering the option of reverb on all or no delays in future. In this configuration, reverb, programming possibilities are limited in comparison to those under HQ Reverb.


Remember those seven status LEDs on the front panel? They indicate two things: which types of effect are active in any configuration, and which effect (if any) is currently being edited. By now this display is becoming useful. I can see that in the Multi Effect configuration I am being offered EQ (as usual), plus Modul(ation), Delay and Reverb. Now the maximum delay time is limited to 230 bpm (260ms). Mono and stereo flanging, phasing and chorus are available as modulators. The delay and reverb combination operates as above, with modulation first in line before any other processing.


This Configuration is similar to the above, except that a single pitch shifting line is used in place of a modulator. As the harmoniser comes before the delay and reverb, it is not possible to generate chromatic cascades. Pitch balance can be adjusted between 100% transposed and 100% original signal in 100 1dB steps. When 100% transposed is selected, there is a 'dry' transposed signal, followed by reverberated echoes of same. When 100% original is selected, only the reverberated echoes of that signal are heard, provided that the Original Level parameter is set to off (as it should be for most applications).


Gate has disappeared from the reverb options in this expansion of the Multi Effect configuration which includes a dynamics processor — a distortion unit. New parameters are Distortion and Voice Filter. The latter is a low pass filter which offers 6dB of emphasis in a peak before the slope starts to fall away, so it's quite colourful, and can take values between 1-7kHz in 100Hz steps (smooth), and off. I didn't have a Les Paul handy, but on a Fender Rhodes sample it certainly sounded useful.


This offers two independently delayed outputs, with just over a second available to each. No regeneration is offered, but the Delay Time can be given in milliseconds, feet, inches, meters (sic), or centimeters. This is obviously for large PA installations where delay clusters are used, although the hire companies might have preferred two completely separate delay lines rather than the 1 >2 configuration offered here. Looks easy enough even for a roadie to understand, however.

That wraps it up for configurations and what lies therein. So what's left? The Config button lies between Edit and Compare. The latter's function is self explanatory — use it in Edit mode to see how much damage you've done, and Store your monster into any one of 128 user memory locations.


If you want to keep your fave edits secure, why not save them over MIDI? You can dump the current program (all good black boxes should do this, but many don't); alternatively you can bulk dump all 128 user programs, also system data and the user-definable program change table. There is also a MIDI activity monitor, for checking the datastream on any MIDI cable you care to hook up to the DRP15.

By the time you read this, version 2.0 software (on a user-replaceable EPROM, free to all DRP15 owners) will have brought dynamic MIDI to the DRP15 in a big way. I'm told that all adjustable parameters will be MIDI controllable. Four controllers (including the foot-pedal if you wish) may be patched into every program for simultaneous real time editing, and the sensitivity and sense (eg. for negative controlling) of these will be easily adjustable. As with the Lexicon PCM70 we should expect regular software updates for this unit. C-Lab and Cubase MIDI Manager editing templates will also be available.


A bypass switch would have been useful. The factory programmer must have realised this, since one of the programs is set up to provide a totally dry signal path, but winding between two programs to compare wet and dry is tedious compared with using a dedicated button. The easiest way I found to A/B wet and dry was under the Configuration menu, where one out of 10 possibilities is Direct Only. At least here you only have to scroll through a maximum of 9 settings, as opposed to 128 programs!

Why was there no HF (or any other 'F') rolloff on the delay line's decay? After all, HF and LF damping is available on reverberation programs. (There will be, however; see 'STOP PRESS')

The harmoniser section requires some attention: it would be good if the sampling delays could be reduced. Also, it would be great to see MIDI keyboard defined pitch intervals, and intelligent diatonic harmonising.


I can see the DRP15 being purchased by professional studios and studio equipment and PA hire companies. It slots into the dedicated reverb market perfectly, being immediately usable and offering industry standard sound quality, while undercutting the immediate competition. In fact I preferred it to my previous favourite, the Lexicon PCM70. The new MIDI spec should appeal to power sequencer users, as it promises to offer easy access to real-time recording of parameter adjustments.

If you or I were about to spend the best part of a grand on an effects unit, we'd probably be thinking in terms of a parallel processor with vocoding options. Still, I am reluctant to part with the DRP15; the sheer quality is addictive.

Further information

Dynacord DRP15 £869.50 inc VAT.

Shuttlesound, (Contact Details).


When they heard about the bugs in the pitch shifting program, Dynacord ordered an immediate investigation: within hours they cured the panning problem, and the new software has already been updated to account for this. Quote: "We have beta testers out there and none of them picked it up." Seems to re-inforce my belief that professionals rarely have the inclination to delve deep into FX programming!

A pre-release of v2.1 software is currently en route to me from Germany. (The production version will have been released before you read this). Dynacord agreed that the next software update should have damped decay delays, and want to hear from users as to what other changes they might want implemented in the future. Now that's what I call an attitude!

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Ministry Of Sound Ideas

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Sound On Sound - Copyright: SOS Publications Ltd.
The contents of this magazine are re-published here with the kind permission of SOS Publications Ltd.


Sound On Sound - Feb 1993

Gear in this article:

Studio FX > Dynacord > DRP15

Gear Tags:

Digital FX

Review by Wilf Smarties

Previous article in this issue:

> Ministry Of Sound Ideas

Next article in this issue:

> SOS On-line

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