NBS Audio Universal Tone Control

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As shown, this perfectionist product is built around a pure clear-coated copper chassis. The pictures do not do it justice. This is a piece of audio art.

Supplied with:

1. A 20 amp IEC NBS Black Label II+ AC cable. See picture.

2. The original shipping wooden crate

3. Description by the designer, Dr. Michael Shields:

"You normally think of a tone control in terms of crude "bass" and "treble" knobs. As a practical matter, such controls are much too coarse to accomplish anything but a gross tonal modification.

If you have a lot of recordings and use really good playback equipment, you have undoubtedly observed that many recordings are tonally deficient in some way. Maybe a little too bright, not quite enough deep bass, not enough presence, and so on.

This problem arises from two facts: first, you are not listening in the exact same way as the people who produced and balanced the recording, and second, your personal preferences may differ from those of the producer. These differences of taste and preference are not susceptible to an argument, they simply are what they are.

The most important determinant of tonal balance is the frequency response. Small variations in frequency response can have a very large effect on perceived tonal balance.

Hence, the NBS Universal Tone Control.

It offers adjustment of the frequency response in 6 bands which subjectively correspond to the attributes of:

            Powerfulness, deep bass                     40 Hz control
            Body, solidity, mid-bass                     150 Hz control
            Warmth, lower midrange                    500 Hz control
            Presence, upper midrange                   2500 Hz control
            Brightness, sibilance, low treble         5 kHz control
            Brilliance, high treble                          10 kHz control

The amplitude of each band is independently adjustable, either to boost it or to reduce (attenuate) it. Very fine adjustments are possible.

Output level trim controls are provided for each channel because sometimes changing the tonal quality will affect the apparent left-right balance. This can be corrected using these controls.

A Bypass mode is also available so that the adjusted result can be easily compared to the original sound.

A distinguishing feature of the NBS Universal Tone Control is that it allows correction of the tonal balance without corrupting the quality of the signal. As a result, it is a useful addition to even the highest performance system."

Specifications:

Inputs:  L and R, Balanced, Z = 48K Ohms
L and R, Single-ended (unbalanced), Z = 30K OhmsOutputs: L and R, Balanced, Z = 200 Ohms
L and R, Single-ended (unbalanced), Z = 600 Ohms

Any load of 600 Ohms or greater is permissible.

The balanced and unbalanced outputs may be used simultaneously

Gain:0dB, Bypass, or all channels Flat, 
Gain trims at the center Trim range: +5 to -5 dB in 1 dB steps. L and R channels are independent.

Control range: Each of the 6 bands can be boosted or attenuated in the following increments: 0.5 dB, 1.0 dB, 1.5 dB, 2.0 dB, 2.5 dB, 3.0dB, 4.0 dB, 5.0 dB, 6.0 dB, 8.0 dB and 10 dB. The adjustment affects both L and R channels.

Power requirements:  Nominal mains: 100-240VAC, 50-60 Hz. Fully Power factor corrected advanced switch-mode power supply. 
Dimensions:Height: 3.875" (98mm)
Width: 17.000" (432mm)
Depth: 16.000" (406mm) (chassis only)  Weight: 20 lb (9 Kg)