Behringer T1953 manual Best of both worlds, UTC circuit, Studio applications

TUBE ULTRAGAIN T1953

4.6 The best of both worlds

Despite many efforts neither manufacturers nor developers have succeeded so far in simulating these positive properties of the tube by means of other devices. Additionally, the natural capabilities of the tube to act as a soft limiter can only be mimicked with highly sophisticated circuitry. Today’s studio technology requirements are therefore met by a combination of both high-grade semiconductor and tube technologies. In this context, tubes no longer serve their original purpose as amplifiers, but are used for the detailed shaping of sound.

4.7 UTC circuit

In

Out

WARMTH

Fig. 4.7: UTC circuit

The TUBE ULTRAGAIN splits up the audio signal applied at the input and processes it differently for both signal paths. Each of the two tube halves amplifies the original signal and the signal modified in its phase spectrum (twin triode). Additional harmonics are produced by slightly overdriving the tube stage. When the two signals are processed by the UTC circuit, the interference noise found in conventional tube circuits can be largely eliminated, and the actual tube effect be added gradually. The more you turn the Warmth control to the right, the more tube sound will be added to the original signal.

4.8 Studio applications

In a recording studio tubes do not perform the same task as they do in an overdriven guitar amp, where the considerably higher saturation of the tube(s) leads to a full and often deliberate modification of the input signal (in many cases combined with a heavy increase in noise floor levels). In the studio more subtle effects are needed. Here, tube circuits add life to the signal’s tonal character and increase its power to make itself heard. Often, tubes also increase the signal’s perceived loudness (in relation to the unprocessed signal), i.e. the perceived loudness goes up although the volume level remains the same. This is because the dynamic range of the applied audio signal is limited by the tube circuit, while the amplitude of the signal with the lowest loudness is raised. Thus, increasing tube saturation produces a slight compression effect over the entire dynamic range.

A similar effect can be perceived when analog tape is saturated. This saturation effect also compresses the recorded audio material and produces additional harmonics.

18 4. TECHNICAL BACKGROUND