Test Report on: Soundcraft "Sixteen into Two" Mixer
Date: July 1975. £1000 ex VAT.

The "Sixteen into Two" is a large "stage" mixer designed for balancing the sound of live music. Though less expensive than a professional studio mixer, it has most of the same facilities and almost studio performance. The unit is specifically designed to withstand a life "on the road" with a group and, for ruggedness, is constructed in what is called an "aluminium flight case". This is an extremely sturdy aluminium covered, plywood case with strong catches and handles and reinforced corners.

The facilities provided on each input channel are:
(i) 200 ohm balanced line microphone input via an XLR connector
(ii) input sensitivity control
(iii) 4 channel equalisation
(iv) foldback and echo (or reverb) rotary faders
(v) slider main fader and rotary left/right balance control.
(vi) monitor selection and channel off/on switch.

One echo output is provided for driving an external effects units but two echo return inputs, each with its own level control, are fitted. This permits two external effects to be used simultaneously. The echo channel has a full set of four tone controls and foldback and master echo controls.

Each of the two main output channels and the foldback channel has a master fader and bass and treble controls. A headphone monitor channel can listen in on any mixed output or any individual input channel. Two targe V.U. meters can be switched to measure the signals on the main outputs or to measure the foldback channel output on one meter and the source selected by the headphone monitor on the other.

All the inputs and outputs, apart from going to XLR connectors, also go to a single multi-spin socket so that a multi-core cable can be used to connect the mixer to a stage box. This permits the mixer and its operator to be placed out in the auditorium. A suitable multi-core cable on a dispenser, and the stage box can be provided as an extra.

Construction

Inside the sturdy outer case is a single large front panel on which all the working parts are mounted. Each of the 16 input channels has its own printed circuit board; three identical mixing boards are used for the left, right and foldback channels and two further boards carry monitor and reverb channel components; total of 21 printed circuit boards. On current units these are made of phenol bonded paper but glass fibre boards are being fitted to all new units.

Components with any significant weight are not mounted on the printed circuit boards but are directly bolted to the main panel. These include the 16 mu-metal shielded input transformers, the toroidal mains transformers, which is also in a screening case, and the smoothing electrolytics.

A lot of thought has obviously gone into the choice of components and method of construction. The slider pots have the track offset to the slot so that any dust which gets in does not settle on the resistive element and so make the pot noisy. An R.F. filter has been fitted in the mains circuit so that mains-borne interference is rejected. The mains adjuster is next to the mains input socket so it is less likely that one would forget to set it correctly. There are also numerous other small features which indicate attention to detail in the the design.

Conclusion

This is a well considered piece of engineering which will satisfactorily do the job for which it was designed. The quality of components and of construction is good and the facilities and performance well justify the price tag.

In use, one may expect to require inputs from music sources other than microphones. The manufacturers can provide special inputs on request.