Stuzzi Mambo 368W

Additional Info

Taken from The Tape Recorder, May 1959

THE Stuzzi “Mambo” is a very compact little tape recorder of Austrian origin, its particular merits being its small size, 13½ x 10½ x 6½ in., and its low weight, 19 lb. A machine of these dimensions is really portable by any interpretation of the word. However, the small size inevitably involves some sacrifice, and thus the “Mambo” is a single speed (3¾ i/s) machine only, and the maximum size of spool that can be accommodated is the Continental standard of 5¾ in. diameter. These limitations prevent it being used for reproducing any of the commercially recorded tapes, for which a tape speed of 7½ i/s has been standardised. This may be no disadvantage to the would-be purchaser requiring a machine for recording and replaying his own programme material, but this reviewer finds it a serious limitation.
The “Mambo” is above average in styling and finish, the case being covered in an attractive dark green imitation leather cloth which contrasts nicely with the lacquered brass trimming and the cream moulded top plate. A simple form of spring retainer is fitted inside the detachable cover to hold the spools in position during transport—a simple device that might be more widely adopted. In spite of the small size, adequate space has been found in the machine for storing the mains lead and its plug, also a spare input lead and a microphone.
Operation is extremely simple, for the controls have been reduced to the absolute minimum. Between the spools, at the rear of the deck, is the wind and re-wind control; while on the left-hand side is the volume control, used for both recording and replaying, and a concentrically-mounted mains switch. In the front centre is a three-position, lever-operated switch that selects “record” or “replay”—and this is also used to lift the tape out of contact with the capstan when an “instantaneous stop” is required while dictating or transcribing. An edgewise-mounted tone control on the right-hand side is balanced by a similar knob on the left-hand side, operating the recording interlock, which prevents the central lever being accidentally moved into the recording position. A volume indicator, of the EM81 magic eye type, and a three-digit counter, are fitted; but the restriction to single speed operation allows a “minutes-of- tape-still-to-run” indicator plate to be fitted under the spools.
Input sockets for “radio” and “microphone” and an output socket for an “extension loudspeaker” are concealed behind a neat trap at the rear of the machine.
Objective Tests
The combined record and replay response is shown in fig. 1, which also indicates the range of the tone control. The tone control is unusual in that it tips the frequency response curve about a point in the 1,000 c/s region, to produce “bass boost” as well as “top cut”. This is probably the most effective form of single-knob tone control. Though the frequency response is too restricted to allow the performance to be classed as “high fidelity” it is undoubtedly more than adequate for the vast majority of applications for which a portable machine would be used.
The signal/noise ration (the ratio in dB of a 1 Kc/s signal, recorded at full modulation to the residual noise remaining after the recorded tape had been erased on the machine) was 38 dB, there being no significant difference between the weighted and unweighted values. This is probably due to the attenuated low-frequency response indicated by fig. 1.
At 0.32 per cent, the total wow and flutter was a little on the high side for the reproduction of music, but it is perfectly adequate for speech reproduction. There are vague signs that commercially-recorded tapes, suitable for 3¾ ips may appear in the future, but if they do it will be necessary for the machine designers to improve the mechanical performance of most existing tape recorders. Many machines operating at 3¾ ips have a frequency response that would do justice to commercially-recorded tapes, hut very few machines have low enough values of wow and flutter.
The Acos microphone, provided with the machine, gives acceptable quality if it is not used too close to the speaker’s mouth.
A single EL84 is employed in the output stage, giving a claimed output of 2.5 watts.
General Comment
Apart from its inability to replay the commercial tapes recorded at 7½ ips, the Stuzzi was liked by the friends who used it. It is mechanically quiet; the braking system is exceptionally effective; and the tape spools evenly and neatly on the high speed rewind. The number of controls has been reduced to the absolute minimum and, in consequence, the operation is extremely simple and is almost foolproof. No trouble was experienced during a month’s use. The machine is not a high fidelity reproducer in the strict sense but the performance is adequate for most uses and, in fact, it is far better than the performance of the vast majority of radio receivers.
James Moir