Studio microThe TLM 170 R was the first microphone with the now so successful fet-100 technology. It offers balanced transformerless signal output and maximum controllability with extremely low noise.
Five directional characteristics can be selected with a rotary switch. In the sixth switch position "R", the directional characteristics can be switched over by means of the N 248 power supply without the need for a special cable.
The microphone also has a switchable 10 dB pre-attenuation for very high sound levels and an impact sound filter with an operating frequency of 100 Hz.
Scope of application
The condensation microphone TLM 170 R is a switchable large diaphragm microphone, which is distinguished by its transmission characteristics and different switching possibilities. It is used in a wide variety of applications in broadcast, film and television, as well as in the semi-professional field.
The directional characteristics can be switched directly on the microphone as well as by remote control from a designated power supply unit.
The double diaphragm capsule in the wire mesh basket of the microphone has particularly flat frequency characteristics for all adjustable directional characteristics. This is not only true, as is often the case with the sound coming from the front, but also for sound which laterally falls within an angular range of more than ± 100 °.
As a result, the diffuse-field frequency paths up to 10 kHz also run parallel to the 0 ° curves. In practice this affects the sound parts arriving indirectly via reflections in the recording space to the microphone.
This also means that the microphone does not alter the sound characteristics of the microphone. Since no resonance effects are used to achieve the above-mentioned microphone characteristics, the pulse response of the microphone is excellent. It is thus able to transfer all balancing processes in music and language without any distortion. The capsule is elastically mounted for protection against structure-borne noise.
In addition to the usual directional polar patterns: omnidirectional, cardioid, and figure-8, we have added a hypercardioid and wide-angle cardioid characteristic. When compared to the standard cardioid pattern, the hypercardioid characteristic suppresses sound from the side more efficiently. The wide-angle polar pattern is especially useful to record large sound sources.
The remote control of the directional characteristics using the power supply unit N 248 is achieved by varying the phantom voltage in the range 48 V ± 3 V (the corresponding standard allows a range of ± 4 V).
In the switch position "R" (= Remote: Remote control), the TLM 170 R microphone evaluates the absolute level of the phantom voltage and adjusts itself into the associated directional characteristic. As with conventional operation, the normal 3-pin microphone cable is used, cable lengths up to 300 m are permissible.
The letters TLM stand for "transformerless microphone". The TLM 170 R normally replaces the commonly used output transformer with an electronic circuit, which - like a transformer - ensures a good unbalance. Therefore, spurious signals acting on the balanced modulation line are suppressed as usual.
Operation on tripodsFor mounting on a tripod, the TLM 170 R has a side-mounted swivel bracket that effectively protects the microphone from low-frequency, mechanical vibrations due to built-in rubber elements. It can be removed if required or mounted on the other side of the microphone.
To use the cable IC 4 (for example, to suspend the microphone from the top in conjunction with the tilt device MNV 87), the pivotable bracket with its holder must be removed from the microphone. Then a thread for screwing with the cable is released at the connecting part of the microphone.
Filter & Pre-Attenuation
In order to prevent an overdriving of the downstream amplifier input, a pre-attenuation of 10 dB can be switched on at the rear.
A further switch allows the lowering of the frequency response below 100 Hz for suppression of low-frequency interferences.
The surface of the capsule, including the diaphragms, is at ground level and is therefore insensitive to electrical and atmospheric influences as well as to dirt.
5 Polar patterns: omni, cardioid, figure-8, hypercardioid and wide cardioid
Remote control with N 48 R-2.