The 3050 model digital delay line is currently part of the ever-expanding and very popular range of Fostex home recording equipment and as such offers the home or budget recordist digital quality effects at a very reasonable price. The full complement of delay effects; flanging, echo, chorus, vibrato and reverberation can all be achieved simply and efficiently using the 3050.
The unit is designed for operation at -10dBV line levels, making it fully compatible with most budget-priced tape recorders and mixers, and can be patched via echo send/return sockets or inserted into a separate channel of a mixing desk for individual treatment of a sound source if so desired.
The 17" x 1¾" grey coloured front panel has a logical layout and all control function labels are easy to read, being situated above each control knob rather than below, which is sometimes the case. Power is applied via a slimline pushbutton to the far right and a corresponding LED indicates the power status. Connection of an audio signal input is via the rear panel phono socket labelled Input, an adaptor being required if a standard jack is to be connected. The front panel Input control knob has three level indicators labelled Present, Norm and Limit which give a fast and accurate means of obtaining the best undistorted input signals. A good signal-to-noise ratio can be maintained when this input level control is set high enough so that the red Limit LED glows occasionally on peak signals.
The Delay Time section contains two controls which together enable any delay time to be set between 0.13 mS and 270 mS. The first control selects delay range from 0.27 mS to 137 mS in ten fixed steps and the second control permits the user to vary this selected value from ½ to 2 times if required. The longest delay possible is thus approximately 270 mS, which is enough to give a distinct echo. A Feedback control adjusts the amount of delayed signal that is to be recirculated into the delay circuit to increase the number of echo repeats. On near full Feedback setting (8 or 9) the delayed sound will repeat happily for many seconds; a facility that can be used to great effect to produce sound 'textures', as new and echoed phrases overlap one another in a continuously moving sound field. However, maximum feedback can cause a rapid build up in signal level as the feedback loop gain exceeds unity and care should therefore be taken when setting this control to prevent any overload. Used with taste, this feedback effect can produce a very interesting sound.
The combination of compressor-expander style noise reduction circuitry and the 10 kHz bandwidth at all delay time settings, means that noise is hardly a problem with the Fostex, and the resulting delayed signal does not lose too much bite remaining, in the main, clear and crisp.
The provision of a low frequency oscillator (LFO) permits the delay time to be internally modulated to produce both flanging and chorus effects when used in conjunction with the front panel Depth and Speed controls. The modulation Speed ranges between 0.1 Hz and 30 Hz, giving a usefully long, ten second sweep for slow flanging effects which sound good when applied to sustained string synthesiser chords, for example. A modulation limit indicator to the left of the Depth control lights up to tell you that the delay time being swept by the LFO, has exceeded its available range - namely ½ to 2 times the delay time set by the fixed range selector switch. This acts as both a warning and safety device when using the rear panel Cont In socket which allows the delay time to be externally controlled by a 10V peak to peak voltage. No matter how large the voltage being applied is, the delay time will not exceed its fixed range limits, thus removing any overdrive problems that would otherwise have caused severe problems. The delay time can either be set externally by a DC voltage or by routing an LFO from a synthesiser to modulate the time delay for example.
The Output Mix section completes the front panel description and contains separate output level controls for the Dry (unprocessed) and Delayed signals allowing subtle blends of each to be achieved. Finally a Phase switch to the right of the output section inverts the phase of the delayed signal being applied to the feedback and output mixing circuitry. It is most effective when a flanging effect is selected enhancing the cancellation effect.
On the rear panel the Fostex delay unit provides the user with Input and Foldback sockets, effectively giving two inputs, and Output and Aux Out sockets, all of which are the standard phono type. The latter two sockets give identical output signals derived from the relative mix of Dry and Delay signals on the front panel. Twin outputs are very handy in a budget recording system as one can be routed to the echo return of a mixer and the other directly to another effects unit for further signal processing for example. Unfortunately, no footswitch connection is provided, probably due to the fact that the Fostex is geared more towards recording applications than to live performance; nevertheless, a footswitch option would have increased the versatility of this unit even more.
As already mentioned, an external voltage can be applied to the Cont In socket for delay time control, which is a very useful feature and one that begs to be exploited by any synthesiser owner. A one volt increase of this external voltage will increase the delay time by 1.15 times its preset value. A 5 volt increase therefore doubles the delay time. Controlling the time delay with an external control voltage derived from an envelope generator gives some extremely unusual delay effects, depending of course on the type of envelope you use. A long attack for example causes the delay time to be gradually increased whilst a long decay has the reverse effect. The scope for special delay treatments that this unit offers is limited more by your own imagination and spirit of adventure than by the inherent limitations of the unit itself!
A comprehensive Owners' Manual accompanies the unit giving some very useful operational tips and a fine selection of example applications. All in all, the Fostex gives a good, wide selection of quality delay effects. The reverberation has that characteristic metallic sound to it that you associate with single tap digital delay lines. Fostex have no doubt looked carefully at the home recordists' needs for a good, reliable delay unit that can produce an extensive range of effects but won't cost the earth. The model 3050 digital delay line certainly fulfills those needs and offers the bonus of voltage control of delay time as well.
The Fostex 3050 is available from Turnkey, (Contact Details).