In this digital age, it is interesting to see what the analogue units have to offer. Paul White relates his experiences with the SF-010 Flanger/Chorus.

It can be difficult to thoroughly evaluate a device when you are only able to hang on to it for a short space of time but that is not the case with this unit. I bought one nearly a year ago and I think that I now know it well enough to give it a fair trial.

In spite of their silly name [no more jokes about burnt instant curry - Ed!], Vesta Fire produce some very creditable signal processing equipment and usually at sensible prices.

The Dual Flanger/Chorus fits this description having a specified signal-to-noise ratio of 80dB and a frequency response of 20Hz to 15kHz for the delayed signal and 20Hz to 20kHz for the dry signal.

By means of a simple switching system, the two channels may be configured as two mono units or a single stereo unit running from a common modulation oscillator. As the technology required to produce flanging and chorus is very similar, it is reasonable to produce a unit capable of providing both effects and, for some reason not yet adequately explored, analogue chorus-flangers seem to be able to produce deeper effects than equivalent digital processors.

Construction

Before launching into a description of the control functions, I'll briefly launch into a description of the black 1U rack case. This is a fairly standard steel case measuring 485 x 44 x 240mm with a clear and attractive front panel which houses all the controls and switches with the exception of the level selectors, these being mounted on the rear panel. There are also removable rubber feet for stand alone use. All the control knobs are neat and tastefully colour-coded, the panel being finished off by an illuminated pushbutton power switch.

Internally, the circuitry is soundly constructed and the heart of the system is the MN3007 CCD delay line chip which provides the necessary time delay for chorus and flanging effects.

Controls

Each channel has its own sensitivity selector for line or instrument matching, the maximum input levels being +16dB and +6dB respectively. A common LFO control enables sweep rates of between 0.1 and 15 seconds to be set up and each channel has an output selector enabling the dry, the delayed or the mixed sounds to be routed to the output and a footswitch facility is included on the rear panel.

To produce chorus and flanging, three additional controls are necessary: delay time, feedback and depth of modulation. Delay time is variable from 1.2 to 17ms giving adequate range for both effects, and the feedback control is necessary to provide flanging.

There are three distinct modes of operation for the unit in terms of its dual channel capabilities and these are as follows: In its simplest form, the SF-010 can be treated as two entirely separate effects units, the only common control being the LFO rate. If a signal is presented to only one input, it is automatically routed through both channels enabling a mono signal to be processed, giving a pseudo stereo effect, and setting the controls differently on each channel will enhance this effect.

Lastly, two signals may be processed independently by both channels but the outputs are combined into mono giving a simple mixing facility.

In Use

I have tried all the operational modes but by far the most useful is to produce a stereo output from a mono input. Chorus effects produced in this way are particularly good and, though no information is provided on the subject, the outputs sounded as if they are being swept in opposite directions, as though the LFO feed to one delay line is inverted. In subjective terms, this gives a wide dynamic stereo effect.

Used as separate mono chorus units, the effect is still good being relatively noise free and bright, but in this case, the common LFO is somewhat of a limitation.

Used as a flanger, by setting a short delay and heavy feedback, a high quality effect can be produced but the depth is still not as great as can be obtained from a dedicated flanger pedal.

I have used the unit on guitars, keyboard and bass guitar, all with encouraging results and the unit does seem very tolerant of input levels which is just as well in the absence of any level indicating device. The handbook does contain a number of sample settings to get you started and all these worked well so you should have no trouble in producing the right sounds.

Conclusions

This is a well constructed and so far reliable unit that performs to a high standard in terms of its sound quality. The only negative aspects are the lack of level indicators (even a peak LED would do), the common LFO and the slightly weak flanging; but the positive attributes still make this processor a very desirable piece of gear.

As a true stereo chorus unit, I don't know of anything to touch it at the price and the flanging is very usable if not the most dramatic that I've heard.

For effects requiring only short delays, analogue units can be better than digital because there are no quantisation noise problems and the performance of short analogue delays in terms of noise and bandwidth is more than adequate.

If you want to add instant spice to your recordings or live performance, try putting one of these Vesta units in your spice rack!

Recommended selling price £273.70 inc VAT.

Details from MTR, (Contact Details).