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DOD R-910 Digital Delay | |
Article from Home & Studio Recording, August 1984 |
So, onto the review unit in question, the R-910 digital delay. Part of a group of three new delay devices, the R-910 is capable of a maximum delay of 1900 milliseconds (just under 2 seconds) and has a 'full' delay bandwidth of 15kHz, which should mean that your delayed sound is virtually indistinguishable from the original.
To make using the DOD unit easier, the device incorporates front panel buttons to select one of four preset effect modes - either Flange, Chorus, Double or Echo. Although not as useful as on-board programmable memory facilities, these presets do allow very fast changes to be implemented, a feature that is probably of more use in a 'live' situation. The choice of presets are generally good, except for the Flange mode which needs modifying by the addition of extra feedback - but that's a purely subjective view.
All presets can be modified within certain ranges. For example, with the Delay Time control turned fully clockwise (to its x1 position) all presets will be set to the delay time specified below each preset selector button ie. Flange 14ms, Chorus 22ms, Double 224ms and Echo 1900ms. Turning the said Delay Time control anticlockwise will then gradually reduce the delay time to a minimum for each preset, corresponding to one tenth of the preset value (x0.1). Therefore, using the above controls any delay value from 1-4ms right up to 1900ms can be obtained, but not very accurately as no visual display of your selected time is available. This will probably not worry too many potential users, as the majority of people I know rarely utilise such a display, preferring to rely upon their ears whilst setting up effects.
As already mentioned, the four preset effects can be modified by the user through the remaining controls. Delay time can be automatically modulated to enhance the chorus setting for example, using the Speed and Width controls - the former controlling the rate at which the delay time is swept (from 0.06Hz to 6Hz), the latter determining the range of delay sweep (from zero to 100%). Used in combination, there's enough scope available from the modulation section to create all of the usual delay-based effects such as Doppler, Leslie speaker, vibrato, phasing etc.
The provision of a Feedback control with both positive and negative settings further assists in the range of effects possible from the R-910. With Echo selected, increasing settings of the Feedback pot introduce further echo repeats, whilst in Flange mode it enriches the effect dramatically. A useful centre detent on the pot indicates the 'no feedback' setting. One small criticism is that it is impossible to obtain 'oscillation' on full feedback. Although this does prevent distortion and overload, it does restrict you from creating those 'run-away' repeat echo effects that are so effective on the build up to a song chorus, for example.
With the Repeat Hold feature, it is possible to 'freeze' a sound in memory and have it loop around continuously. The maximum delay of 1900ms means that some quite long musical riffs can be held and repeated over and over again - very suitable as a foundation to a song or for Robert Fripp guitar impersonations. As is usual on digital delays, the pitch of a frozen sound can be altered using the Delay Time control for all manner of weird and wonderful sound effects. A rear panel socket also lets you control this function via an accessory footswitch; most likely to be employed in a concert situation rather than in a studio.
Input and output levels are determined by their respective gain controls and a four LED display gives some form of indication of the input level in dB. The final control, Output Mix sets the balance of dry and delayed signals and is best left on full delay when the R-910 is linked to the echo send/return loop of a mixer.
Moving to the rear panel the user is confronted with a good selection of connections, which all utilise standard quarter inch jack sockets. In addition to the Input socket, there's Dry Out (no delay signal), Mix Out (the combination of dry/delay signals determined by the Output Mix control), and Phase Out, which gives an inverted, out-of-phase, delayed signal mixed with the dry. Using both Mix and Phase Out sockets lets you create quasi-stereo effects, but be careful with these if you intend producing a mono recording from stereo, as the in-phase and out-of-phase delayed signals may well cancel each other out completely.
In addition to the Repeat Hold socket, a further footswitch can be connected to the Delay Kill socket to do just that. The final socket, labelled Control Voltage, gives access to the internal VCO for external modulation of the delay time. Connecting the control voltage from a synthesiser's Sample and Hold to this CV input proved extremely good at imitating 'dub' echo effects when treating a drum machine. It's always handy to be able to control delay time externally, even if there are only limited styles of music that can incorporate the effects possible from such a setup.
Input Level: | -25 to +20dB |
Input Impedance: | 470Kohms |
Output Level: | +13dB max |
Output Impedance: | 600 ohms |
Frequency Response: | 20Hz - 20kHz (dry) |
40Hz - 15kHz (delay) | |
Signal-to-Noise Ratio: | 95dB (dry) |
87dB (delay) | |
Dimensions: | 1⅜"x 19" x 8" |
Weight: | 5.2lbs |
Soundwise, the DOD delay offers high quality effects due to the low background noise and wide effect bandwidth. However, there are many digital delay devices around today with equally varied effects features that lack only the full bandwidth specification of this DOD unit, and which retail at considerably lower prices. If sound quality is high on your list of priorities, you'll have to look hard to find a unit as good as this, but if it isn't, then there are those alternatives. For the asking price of £523.25, you'd be right to want some form of programmable memory facilities on such a unit, and this ought to be where DOD look in the very near future. All in all, a good, workmanlike delay unit that offers some high quality usable effects in a standard 19" rackmounting package.
R-910 Digital Delay System £523.25 including VAT.
Further enquiries to: Libra Electronics Ltd., (Contact Details).
Review by Ian Gilby
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