Townshend Allegri Reference MKII Passive Preamplifier

PASSIVE AUTOTRANSFORMER VOLUME CONTROL (AVC)

There are 129 individual 0.5dB steps, which give very fine volume adjustment at all listening levels. This incredibly wide range can accommodate very high source levels and very high sensitivity power amplifiers enabling refined volume control at very low levels (ideal for late-night listening). This is a ‘first’ for an AVC. In use, the control is seamless with no discernible steps. The Allegri Reference is the Holy Grail of audio preamplifiers.

The autotransformer configuration is employed for the Allegri Reference, (as in the “stunning” Allegri+) because it has been shown to give by far the better sonic result, when compared with conventional transformers (TVCs). The AVC also allows for a smaller core size. It has lower leakage inductance, which gives a far better transient performance and flatter frequency response. The AVC, is also much better than a resistive passive volume control, due to the very high input impedance and low output impedance.

The winding of each transformer comprises a single, unbroken, 260m (845 feet) length of 0.1mm (42SWG) Fractal™ wire, looped out 48 times around 48 pins, which are connected directly to the reed-relay pins. A short run of Fractal™ wire connects each of the signal in, signal out and ground, between the input/output connector board and each transformer, relay board. Here is a clear case of less is MUCH more.

The laminations are 50 % NiFe mumetal metal, which gives the best bass performance and lowest overall distortion (less than 0.01%).

FRACTAL™ WIRE

This purely passive autotransformer design is wired throughout with Townshend Audio’s unique Fractal™ wire, which was developed over many years of critical listening, by the most discerning audiophiles, and is audibly superior to plain copper, silver and even DCT copper wire. The result is the most accurate, uncoloured and open-sounding preamplifier possible, offering astonishing transparency and resolution of the finest details.

To realise the full potential of the Allegri Reference, it is most important to use Townshend Audio F1 Fractal™ interconnects for both input and output, as just one metre of inferior interconnect can noticeably degrade the sound.

FRONT PANEL CONTROLS

The left-hand front rotary control selects the inputs, 1 to 5. If the control is pressed, it toggles the volume level display, between numerals (1-129) or decibels (0 to -72.7). The right-hand control adjusts the volume. When pressed, the sound is muted.

REMOTE CONTROL

With the remote control, you can operate volume change and mute, select any one of the five inputs and program a specific pre-set level. Display blanking is also switchable from the remote.

One press of the volume, up or down, changes the volume by one step of 0.5 dB. If the button is held down, the volume steps will be spaced at half-a-second at first and then the stepping rate will increase. This allows for large volume changes, in a relatively short time, with the entire range from 1 to 129 in covered in 10 seconds. In use, it feels just right.

Each of the five inputs may be pre-programmed, with your chosen volume level, to accommodate the often widely varying output levels of different source components. This brings ease and convenience. Any input may be pre-programmed with zero dB for home cinema bypass. The home cinema bypass feature allows the Allegri Reference to effectively disappear, as it directly connects the AV receiver, to the front left and front right power amplifiers. The volume is then controlled by the AV receiver.

The remote is an Apple-style remote control. It is very sensitive, so it is not necessary to point it directly at the unit. There is a convenient magnet attachment to store the remote under the front of the unit.

DISPLAY

The display is an easy-to-read, white LED, seven-segment array, mounted behind a grey panel. The LED displays are employed, as they are powered by interference-free DC, whereas, if a common LCD type screen were used, the sound would be compromised by the continuously running, refresh clock.

The brightness of the display is controlled by an ambient light level sensor, so that the display is optimally readable when viewed in either bright light or total darkness. Display on/off is switchable by the remote control. The decimal point, on the input channel-display, flashes with each input from the remote. This function is still active when the display is blanked.

CLOCK DISABLE

It is well known that digital clock oscillators degrade the fidelity of the fragile audio signal, so the sound-blurring internal clock is disabled when listening. The clock is only activated when the remote control or the front panel controls are operated.

REED RELAY SWITCHING

The signal path is as simple as possible, with just four of the 96 ultra-reliable reed relays in the signal path at any one time. Reed relays are chosen for their tap switching, as they have a life in excess of 30,000,000 operations, compared with regular rotary switches, which tend to wear through the thin contact plating after a few thousand operations. Further, the relay contacts are in a vacuum, so there is no oxidation and there is a slight rubbing action when the reeds close, which ensures perfect contact for audio. All internal connections are hard-wired with Fractal™ wire with no connectors in the signal path.

CONNECTIONS – BALANCED and UNBALANCED

The phono circuits are unbalanced for simplicity and the XLR connectors are wired in parallel with the phono connectors. The configuration is pseudo-balanced with pin 2 of the XLR signal and pin 3 ground. This avoids the use of an extra balancing transformer, with all the associated complications and degradations in sound. The Allegri Reference has five stereo phono inputs and two pairs of balanced XLRs, in parallel with inputs 1 and 2. There is a 3.5mm jack socket, on the front panel, in parallel with input five. For output, it has two sets of stereo phonos and one pair of balanced XLRs. The result is a preamplifier that can perfectly match any “Red Book standard” source component to any power amplifier.

DIGITAL CONTROL

All microprocessor programming is done in-house, by Townshend’s digital team.

SEISMIC ISOLATION

Seismic Isolation is fundamental to the design of the Allegri Reference. Isolated from vibration down to 3Hz, in all three planes and offers unmatched performance as a result. The four sturdy supporting feet contain fully-featured, highly compliant, air-damped Seismic Isolation modules. These block structure-borne vibration from reaching the autotransformers. This has a remarkable effect on the sound quality and is easily demonstrated, by bypassing the suspension. When bypassed, the sound is exceptional by any normal standards, but when the suspension is incorporated, the soundstage expands dramatically, with height, width and depth being greatly increased. With individual instruments, there is an easily discernible improvement in focus.

CONSTRAINED LAYER DAMPING

As a further part of the comprehensive vibration reduction, heavy mass-damped constrained-layer damping is employed in the structure of the chassis. This extra mass also greatly reduces the effect of external vibration, especially that introduced by interconnect cables.

FULL DEPTH CABINET

The Allegri Reference casing is full depth, front to back, at 380mm (15”). This is most convenient, as it places the controls of the unit at the front of a typical hi-fi rack shelf whilst the connectors are conveniently accessible at the rear.

CABINET FINISHES

The case and isolating feet are made of anodised aluminium and are available in either a natural silver or black finish.

THE POWER SUPPLY

Although the signal path is totally passive in the Allegri Reference, the electronics and the display require 12V DC. A linear power supply (not switch-mode), is supplied as standard, with the appropriate plug to suit your country’s mains supply. Power and the music signal are always separate. There is no direct connection between the power supply and the signal conductors or ground.

CONNECTING

To maintain the integrity of the Fractal™ wired transformers, it is strongly advised to use Fractal™ Interconnects for both the input and output cabling and to use Townshend Audio’s F1 Fractal™ speaker cable. This has been shown to give the best possible sound.