Boss DE-200 Digital Delay
A look at the latest in digital delay - that can be triggered by rhythm machine.
The latest digital delay from Roland subsidiary Boss offers all the standard performance functions associated with digital delay units of this type. It also has the capability to accept trigger voltages from a rhythm machine, so that you can use the DE200 as an external sound source: this feature makes the Boss unique in its class and price range.
The design and layout of the unit makes it a more applicable to studio use than to live stage situations. Considering that three separate controls are used for setting delay time and that the jack from the rhythm-sync needs to be physically removed from the back of the unit in order to return to normal delay function, it is somewhat cumbersome and limited in live work. Conversely, the inclusion of input/output jacks on the front panel which over-ride their companion jacks at the rear is only really necessary for stage work, as in the studio the unit would be rackmounted and connected to a patch day.
The delay time can be set between 1.25 and 128ms by three controls on the front panel. First, a rotary switch selects one of nine preset times from 2.5 to 640ms (each of these is double the previous one: 2.5, 5, 10, 20 etc). This can be continuously altered by a fine-adjustment sweep pot which at maximum is x 1 (preset value) and at minimum is x 0.5 (½ preset value). Thus you have fine control over a range of 1.25 to 640ms. Finally, a switch marked Mode x1, x2 doubles the result of the previous two controls.
Modulation depth and rate, feedback and direct/delay outputs are all controlled by pots on the front panel. Dry, unmodified signal can also be obtained by switching the unit to 'bypass', which takes the signal directly from the preamp stage. Feedback phase can be inverted and Hold mode set by two switches, the state of which are shown by two LEDs.
The rear panel supports eight jack connectors for input, output and the rhythm-sync feature. There are three output jacks, direct (unmodified), mix (direct and delay) and invert mix (direct plus inverted phase delay). These outputs can be used to obtain stereo effect either with direct/delay or delay/invert delay. Two remote (foot-switch) jacks allow control of the Hold mode and bypass facility, over-riding their companion controls on the front panel. The two final jacks are for the rhythm-sync feature; Trigger In and Footswitch (DP-2), which acts as record start/stop when building up the sampled sound.
Boss supply sample settings in their instruction manual for effects such as flanging, chorusing and doubling, and also various echo effects. Generally, these effects are better than normal for this grade of equipment, although flanging is still a little weak compared to purpose-built effects units. Included in the sample settings in 'Fixed Flanging' which uses inverse feedback with no modulation and a fairly long delay time. This gives a very bright signal, easily overloaded, which can be quite interesting. The suggested setting for 'Deep Echo' is rather strange; using the LFO at a slower delay rate creates some interesting effects, but to my mind Deep Echo is not one of them.
The lack of a simple on/off switch for the LFO means that to have a non-modulated signal the modulation depth needs to be turned to minimum. Once modulation is taken out the long delay echo facilities are very good indeed. Decay is very natural, without the sudden drops in signal strength and quality so often apparent with digital delay circuits, where badly clipped transients finally completely break down to clicks and sudden unnatural drops in volume. Boss have cured this problem by cutting down on frequency response, which is somewhat narrower than some other delays with 12 bit CPUs. Even so, the sound quality is quite acceptable even when using long delay times.
This feature allows for a digitally sampled signal to be stored in the Hold circuit and then triggered externally by a rhythm machine or any other trigger voltage supply such as tape.
The unit is switched to Rhythm-Sync mode as soon as the jack is presented to the Trigger In socket at the rear. This sets delay time to max (640ms) which becomes the sample length for the record part of the operation. When recording, the positions of the fine delay pot and the mode switch do not have any direct effect on the recorded signal. On playback, however, they can be used for shifting the pitch of the stored sound. In this way the pitch of the originally sampled sound can be transposed up and down one or two octaves.
If Trigger Out from a rhythm machine is fed to Trigger In on the DE-200, the delay is triggered by the pulse of the rhythm machine, so that the delay output is set in sync with the rhythm machine. The signal to be delayed can be built-up in layers either by directly switching the Hold mode on and off as each voice is added (by footswitch or front panel control) or by footswitch to the DP-2 jack at the back. This allows for greater precision over timing of the recording as related to the rhythm machine, and gaps can be inserted between the trigger pulse and the start of the sound. Both these methods of recording/storing sounds can be supplemented by the audio output of the rhythm machine, but the sound can just as easily be built up normally in the Hold circuit and then applied to rhythm-sync afterwards.
This feature can give very effective results and can also be great fun, particularly when using a microphone as input, as it enables virtually any sound to be triggered and reproduced with surprising fidelity.
The unit is sturdily constructed with all component boards etc. being mounted on a strong steel framework. All switches and controls are very quiet in operation, keeping the signal free from mechanically-induced noise that can so easily cause havoc in this context.
As mentioned earlier, frequency response is a little narrow compared to other 12 bit delays: 10Hz to 10kHz when the Mode switch is set to x1 (max 640ms), and 10Hz to 4.5kHz in x2 mode (max 1280ms). This can give a little falseness to the quality of the reproduced sound at slower delay times. THD is rated at 0.25% and although no signal-to-noise specification is actually listed, the sound is generally clean and free from unwanted noise.
Generally the Boss DE200 is one of the better digital delay units in this price range, with natural-sounding decay and delay-related effects that are as good as any in its class. The added rhythm-sync facility adds a great deal of versatility and opens up many original and creative avenues. The only major moan I have about the DE-200 is the lack of a simple on/off switch on the front panel for the rhythm-sync mode. As long as a plug is in the rear panel connection delay is set to 640ms and can only be operated by trigger signal to that jack. This idea defeats the whole object of using a patch bay with rackmounted equipment, and in live use one is faced with the decision of either normal delay or rhythm-sync, as the two cannot be used simultaneously.
However, the rhythm-sync facility is still well worth having, and is particularly useful if you want to add externally sampled percussion instruments to the output of a rhythm machine.
The Boss DE-200 retails at £299 including VAT, and Roland (UK) at (Contact Details), should have further information. Alternatively you can contact them by telephone on (Contact Details).
Review by Glenn L. Hughes
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