Allegri+

The Townshend Allegri+ is a passive autotransformer preamplifier for matching source components to power amplifiers. Its transformers are wound throughout with Fractal-Wire and use ultra-thin mu-metal laminations. The design is DC coupled, with no capacitors or active devices in the signal path.

Fractal-Wire is used to provide an uncoloured, open presentation with high transparency and fine-detail resolution. The passive circuit requires no mains supply, so it introduces no mains noise or electronic hash and does not require a mains conditioner or dedicated power cord. The Allegri+ has wide bandwidth, low distortion, deep bass and consistent drive across the audio band. Treble is clear without hardness or brashness.

The autotransformer design avoids the impedance limitations associated with resistive passive controls. At the 0dB setting, the input signal is directly connected to the output. The output impedance is therefore the same as the source component’s output impedance, while the Allegri+ input impedance is equal to the power amplifier’s input impedance.

At -6dB, where the output voltage is half the input voltage, the Allegri+ input impedance is 4 times the power amplifier impedance and its output impedance is one quarter of the source impedance. At -20dB, or 10 to 1, the input impedance is 100 times the power amplifier impedance and the output impedance is one hundredth of the source component’s impedance. This arrangement means that interconnect cable capacitance has no effect on Allegri+ performance.

The Townshend Allegri+ has a 6-position input selector, a mute switch and a 24-position volume control. The volume intervals cover a wide range of levels for different systems. Connections comprise 6 pairs of gold-plated stereo phono inputs, 2 pairs of outputs and a 3.5mm input jack on the front panel. The case is made from anodised aluminium.

Quality source components typically provide about 2 volts from a low output impedance, while a competent power amplifier will generally reach full output with 1 volt and have a high input impedance. The Allegri+ therefore does not need gain and, unlike conventional passive controllers, matches the impedance requirements of the source and amplifier so that dynamics are retained.

F1 Fractal-Wire interconnects are essential at both the Allegri+ input and output to preserve the benefit of its Fractal-Wire wound transformers. Townshend F1 Fractal interconnects and F1 Fractal speaker cables are recommended for system optimisation. Female XLR to phono and phono to male XLR adaptor cables are available separately for full balanced operation.