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DeltaLab Effectron Digital Delays

DeltaLab Effectron I.

DeltaLab Research Inc. are an American company who distribute through Atlantex Music Ltd. in Britain. In the increasingly competitive market of digital delays they produce models to suit both semi-pro and professional needs with prices to match. All the units have an uncluttered design with large, well-spaced knobs and pushbutton switches on the front panel, the design philosophy being simplicity and ease of use - you'll find no incremental controls, flashing lights or digital displays here.

Some extra space has been created by combining controls. For instance, on the JR 1050 the fine delay control pot has a centre detent; when rotated in a clockwise direction from centre it acts as a modulation width control, and when moved in an anticlockwise direction, it acts as the fine delay control. This policy of combining controls extends through the whole range of DDLs that DeltaLab produce.

The manuals for the units are extremely comprehensive (no pidgin English), with lots of useful tips on topics like stereo spreading, reverb pre-delay, and how to deal with transients when flanging. The impression is that the manufacturers are eager to help you get the best out of your DDL, whether you are a first time buyer or seasoned veteran.

Effectron 1

This is the most modestly priced unit of DeltaLab's ADM (Adaptive Delta Modulation) range. ADM is a patented technology which DeltaLab claim is superior to the more familiar Pulse Code Modulation (PCM) in that ADM is more sensitive to the dynamic characteristics of musical sound, thus resulting in a more natural sounding echo.

In construction, both this unit and the JR 1050 are under half the size of most conventional DDLs, the dimensions of both units being 1¾"x19"x4". The chassis is made of steel with an aluminium front panel which on the Effectron 1 is blue with white legend. Inside, a toroidal transformer has been used to minimise hum and as far as I can tell it is not a microprocessor-based system but employs discrete logic circuitry. The Effectron 1 has a maximum delay time of 1024ms but one of the things which make it appealing for the price is the 15kHz bandwidth at all delay settings.

Front Panel

One of the things you immediately notice is the omission of any on/off switch or status indicator, and although this is a budget-priced unit I still feel that it is a useful thing to have. Again the input level (set by a pot) is only indicated by a peak light (called 'limit' in this instance) whereas a stepped indicator, as found in other budget units, would have been preferable.

Next to the input control is the feedback control which is a rather different arrangement to most other DDLs, as explained above. At the 12 o'clock setting there is a centre detent at which the echo is set to give minimum (one) repeats, if moved in an anticlockwise direction the number of repeats is increased out-of-phase, and in a clockwise direction the signal re-circulates in-phase.

Feedback can also be used to alter the sound colouration of short effects like flange and chorus. Delay time is selected via two pushbutton switches used in a binary fashion to produce four preset settings for flange (4-16ms), both switches out; doubling (16-64ms), right switch only depressed; short echo (66-256ms), left switch only depressed; and long echo (256-1024ms), both switches depressed.

Manual adjustment of each effect preset is available via a pot next to the preset switches giving 0.25-1 times the delay selected. This control doubles as a modulation width control in the way described above - once again there's a centre detent at which the modulation width is set to zero and the delay manual adjustment set to the shortest delay time within the preset range selected. Rotating the pot in an anticlockwise direction increases the delay time, while rotating clockwise brings in the modulation width over which delay varies from 0 to maximum (4 to 1) of the preset range chosen.

This means that the modulation is only really useful with short delay settings as it is impossible to get a small amount of modulation and a long length echo at the same time. This is a shame and one of the drawbacks of combining controls in one pot. Having said that, the modulation at short delay settings is good and the modulation speed is set by a pot located next to the width control. Finally, on the front panel there is a control for the mix between source and effect.

Rear Panel

The rear panel has four jack sockets - input, output, bypass and infinite repeat (hold). There are no switches on the front panel for bypass or infinite repeat, which means that you have to build or buy some footswitches if you want these facilities (a stereo jack is needed for bypass). Input range is from -32 to +8dBV, with an output level of +8dBV at limit.

In Operation

The flanging is better than on most DDLs I've tried in this price range and is also reasonably quiet. The Effectron 1 sweeps from 4-16ms and allows you to obtain a good quality, deep flange which, when used in conjunction with the feedback control either in or out-of-phase, can give you some very impressive sounds: out-of-phase sounding hollow, and in-phase giving a more metallic sound colouration for those ethnic or industrial flanges. However, turning the feedback control to full will result in an unpleasant oscillation. Chorus With the width control at the halfway position and the speed fairly slow, the Effectron 1 gives a beautiful full-bodied and rich chorus unlike some DDLs in this class which tend to sound thin and uninteresting. Adding feedback moved the chorus towards a light flange which was also pleasant, especially on guitar.

This has a range between 16 and 66ms. More than 32ms and you begin to hear the repeat sound as distinct from the sound source and the manual suggests that you only rotate the delay control this far. You can add modulation but as the modulation width control doubles as the fine delay control, usable modulation can only be introduced at the shorter sweep widths. Slapback echo effects can be produced using either this preset at the longer delay times or the shorter of the short echo settings.

Long Echoes
With an effect bandwidth of 15kHz at all delay settings you would expect the sound quality of the long delay to be pretty good and, indeed, the delay signal was bright and strong, dying away naturally with no sudden drops in volume. There is the usual digital quantisation noise but this is no more than that found in comparable units.

Infinite repeat gives you all the usual facilites of sound storage and pitch changing. Once the sound has been stored using a footswitch (not supplied) connected to the rear panel jack socket, use of the delay controls will raise or lower the pitch of the stored sound. Although I didn't have a user's manual for this unit (not yet in print), I tried some of the suggested settings from the similar JR 1050 manual such as vibrato, hard reverb, robot voice - very good and great fun but not as similar to a vocoder as the manual suggests, rotating speaker effects, pitch shifting, and stereo spreading, all of which the DDL does very well.

One of the more creative ideas in the manual is the tuning of unpitched sounds by turning up the feedback control while in the flange mode.

I found that this was an effect best used to subtly alter the pitch of percussive sounds like snare drum, however, if you want the sound of a robot playing the drums you can get it! By encouraging you to stretch the unit to its limit, the manufacturers ensure that you will get to know your DDL inside out by the time you've tried everything in the manual.

DeltaLab Effectron JR 1050.

JR 1050

This is the most modestly priced unit of the three devices under scrutiny and offers the same facilities as the Effectron 1 but with a reduced bandwidth of 12kHz. Finished in dark brown with a cream legend, the front panel layout is almost identical - the peak LED is labelled 'wink' instead of 'limit' and there is a slight difference in the choice of the double, short echo and long echo presets, which are 16-66, 66-264 and 264-1056ms respectively; the flange preset remains at 4-16ms. This means that the JR has a slightly longer delay but as far as I can see, apart from the bandwidth, both units provide the same facilities, look the same inside (same circuit board and components) and are the same size but have a cosmetically different front panel.

DeltaLab Effectron III.

Effectron III

Like its little brother, the Effectron 1, this unit has a blue front panel with white legend but comes in a more stand 1¾"x19"x10" rackmounting chassis. A red status indicator tells you when the unit is ready to programme and next to it are the program controls which are in the form of five pushbutton switches. The 'write' pushbutton is red and non-latching and to save the program you simply press this button, and before the 'ready' light goes out, depress one of the grey program channel buttons (labelled A, B, C or D) to store your setting.

All the front panel controls with the exception of the input level are programmable so you can save your favourite effects - be they chorus, flange or repeat echo in memory. Programs can be stored for a period of at least 3 months and as long as you use the unit for at least a few hours a week, the program back-up batteries will maintain a full charge. The program delay function is overridden by the digital delay pushbuttons which must be 'out' in order to hear the originally programmed delay setting.

The input level pot has a maximum gain of 30dB to allow low-level signals to be processed, and two associated coloured LEDs which monitor the level as seen by the encoding circuits. For maximum dynamic range, the Lo LED (green) should be full-on with an occasional flashing of the Hi LED (red) during peaks in the audio input. The red LED indicates the onset of clipping and/or slew rate limiting, and there is an additional 6dB headroom allowed for sudden changes in input level.

Feedback operates in the same way as on the Effectron 1 and the JR 1050 (anticlockwise - negative, clockwise - positive). The manufacturers claim that close to 100% feedback, just short of oscillation is possible at either of the extreme settings and I found that this was the case, making possible some amazing extreme flanging effects which you cannot get on other machines. When the feedback is just short of oscillation the regeneration signal passes through a -12kHz low pass filter to minimise noise build-up.

The digital delay section, like the JR 1050 and the Effectron 1, comprises a bank of pushbutton switches and a delay factor control (fine delay). However, as you'd expect, the Effectron III has a far more comprehensive selection. Three white buttons labelled 2, 8 and 32ms select the short delays used for flanging effects while the 32ms preset can also be used for some chorusing effects. A grey button (128ms) selects the delay range most commonly used for doubling, and two black buttons, for 512 and 1024ms, select long delays used for echo effects. When all the buttons are 'out' there is a 1ms delay with which you can get a short flange, and this is also programmable. All the delay presets are adjustable via the delay factor control which varies the basic clock from min.(x 0.25) to max.(x1).

Following their policy of combining control pots, at 10 o'clock there is a centre detent and if moved clockwise from here the control also affects the level of the envelope follower (attack modulator) circuit. This envelope follower is a useful addition and by detecting the amplitude of the input signal it is used to modulate the clock. The result is a time delay that varies with the amplitude of the signal and produces flanging which gives a sweeping up effect as the signal decays - an ideal treatment on drums and guitar.

The LFO section is separate on this unit so you can add a slight modulation at long delay settings if you wish - something which can be very atmospheric on piano sounds, for instance. I feel that for a unit of this price DeltaLab could have provided an on/off switch on the modulation section as you have to zero the width control in order to take it out.

The width control varies the sweep of the internal oscillator and in the maximum position the delay times will vary from x0.25 to x1.25 of the delay preset value. The speed control varies the rate of modulation of the internal oscillator from 0 to approximately 10Hz. The delay mix control enables you to mix different amounts of in-phase or out-of-phase processed signal by rotating the pot either clockwise or anticlockwise respectively from the source position, which has a centre detent.

Rear Panel

Possibly one of the most frustrating things about this unit is that the output control is located on the rear panel which means that it is a pain to adjust if your unit is rack-mounted. Obviously in a studio situation you could just set it up and leave it, but if you are a musician, engineer or producer and carry your effects around to different venues and studios in a flightcase, then it becomes a distinct nuisance.

The output level control varies the output to a maximum level of +10dBV and one stereo jack socket supplies the final audio signal which has been processed by a phase shift circuit to simulate a stereo output. The result is that low frequencies are in-phase while there is a controlled amount of phase shift for mid and high frequencies.

A control jack can be used to modulate the internal oscillator (VCO) using a signal generator, envelope follower, synthesiser or foot-pedal. The voltage range is given as 0 to +5V, where 0V yields a delay factor of x1 and +5V yields a delay factor of x0.25. This input overrides the delay factor set on the front panel but will interact with the LFO width and speed controls - to stop this interaction you have to set the width control to zero.

A stereo socket is also provided for use with an optional footswitch, the ADM-STL, which is, in fact, two switches in one, allowing remote switching of the infinite repeat function, and the activation of the effect bypass function which routes the source signal directly to the output stage, bypassing all digital and feedback paths. If you wish to build your own footswitch a simple diagram is given in the manual.

Remote program selection is also available via a stereo jack socket on the rear panel again using the ADM-STL footswitch or an alternative. There is also a feedback output enabling you to break the feedback loop and use signal processing gear like compressor-limiters on the output. Finally, the sole input on this machine is located on the rear panel.

In Operation

The trump card of this DDL is its ability to creatively vary sound textures using feedback at short delays. When an original sound and a delayed version of it are mixed together, the two sounds are mutually reinforced at some frequencies and cancel out at others.

Such reinforcements and cancellations occur at harmonically related frequencies and this pattern of peaks and dips (comb filtering) can be varied ie. tuned by changing the delay time.

With the Effectron III, I found it extremely easy to pick out and accentuate harmonic overtones with the result that the overtone structure of something like an ordinary polyphonic string synth sound could be dramatically transformed with comb filtering. Experimenting at the 2ms preset with feedback and output out-of-phase, the result is a more hollow sound texture, while in-phase feedback and mix produce something harder. At 8ms, the sound becomes more metallic and some excellent industrial sound textures could be derived from a simple string machine sound. With the feedback full up in either direction, I was able to create many more extreme industrial-sounding effects reminiscent of the Eraserhead film soundtrack.

Flanging on this machine is really excellent and the variety of usable sounds is impressive. The shortest delays are generally best for high frequencies, at 8ms and above flanging tends to bring out the middle frequencies and works well on vocals. With maximum feedback, width at full and a little sweep, a strong rich flange which picked out and accentuated harmonics, moving up and down 'arpeggiator' fashion, resulted. I found that running the feedback on full was no problem due to the minimisation of noise build-up by the 12kHz low pass filter, which stopped the feedback from going into oscillation. When used with the envelope follower, the flange will sweep up as the signal decays - a great effect on drums, particularly cymbals.

Doubling and chorus are as excellent and varied as the flange, and work well with guitar for that great jangly 12-string sound. I also found that if used with the envelope and a little LFO width and speed, a single ADSR polyphonic brass sound from a synthesiser would pitch bend into the note or chord giving the impression that another ADSR had been used to create the original sound. However, I had to be careful to mix in only a little of the treated signal otherwise the effect became too extreme.

There are so many good and usable effects available with this DDL that space just doesn't allow me to go into details - if you want to turn a drum track into something that resembles a tunable robotic sequencer pattern, then this is also possible at 32ms with positive feedback at full and by using the delay factor control to tune the resonances.

One of my gripes (and a lot of other people's) about digital delays is that they tend to sound thin when compared to the old tape echoes. This is not the case with the Effectron range and long repeats sound extremely natural on this DDL.


As a set of effects units, the Effectron range perform very well, but there are lots of things that niggle me about their design and layout. Although the JR 1050 and Effectron 1 are more modestly priced, I still don't like the limitations imposed by combining the fine delay and width controls.

I'd like to have seen some sort of stereo output, or direct and delay separate outputs, a better input peak metering system and a power status light - all of which are available on its competitor's models. Switches on the front panel for bypass and hold functions wouldn't have gone amiss either, but I suppose something has to be sacrificed for the luxury of increased bandwidth at these prices.

The Effectron III also has some ergonomic problems. Output level control is situated on the rear panel, there is no modulation on/off switch, and to my mind four programs isn't enough at this price. But my biggest criticism of these and most other DDLs on the market is the lack of a trigger input. Such a relatively simple (and cheap) addition would open up a whole new range of uses for all these DDLs enabling you to trigger samples or echo repeat rates from sequencers and drum machines.

The user manuals that I was supplied with were both clear and very informative which is quite a rarity these days. DeltaLab, however, face stiff competition from the Japanese who are able to produce DDLs that look like the Blackpool Illuminations for the same price as the Effectron III. But if what you are looking for is an excellent effects unit with a high quality and very natural sounding repeat, simply laid out with no frills, then the DeltaLab range is for you.

Recommended prices for the review models are as follows: Effectron 1 £332.21; Effectron III £697.66; Effectron JR1050 around £199.00 (all inc VAT).

Distributed in the UK by Atlantex Music Ltd, (Contact Details).

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Echoes From The Observatory

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Fostex SPA-11 Powered Monitors

Home & Studio Recording - Copyright: Music Maker Publications (UK), Future Publishing.


Home & Studio Recording - Dec 1984

Donated & scanned by: Mike Gorman

Review by John Harris

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