Metrum's Toasty Trio - Witchdoctor

Netherlands company Metrum cooks up a trio of toasty audio products: a preamp, a power amp, and new mono blocks.

ADAGIO IS METRUM’s first NOS digital preamplifier, incorporating four DAC TWO modules per channel. Each of the new modules house two condensed DAC ONE + Forward Correction modules, as used in its Pavane and Menuet models. The new modules are the same size as DAC ONE – about the size of a credit card. DAC TWO doubles the R2R ladders, which means that the Adagio is running 16 ladder DACs in comparison to the eight used in Pavane.

The Adagio also doubles voltages to those used in the acclaimed Pavane, 30VA Transformers being used for each channel. The combined result of these improvements typically shows a reduced noise floor of -160dB. Pavane’s already impressive noise floor at -145dB has now been improved, providing for even better low level information retrieval.

The new module configuration enables both singular Analogue outputs and for the first time, optional twin Analogue outputs. Adagio has been designed in this way to augment an enhanced Metrum Audio chain. By removing the need for a Preamp and accompanying I/C, a shorter and more direct signal path is obtained straight from D/A conversion, via Single Ended or Balanced connections to… Metrum’s Forte.

With an interest and background in valve hybrid design amplifiers going back two decades, Cees Ruijtenberg’s preferred valve has been the 12AT7. To evaluate their DACs over the years, Metrum have used their own design amplifiers, with preamp duties performed by a transformer volume control unit (a variant of Aurix), combined with hybrid (S/S) tube 50wpc mono blocs. Class A designs with minimal feedback.

But tubes have their problems. So to try and incorporate the sonic virtues of valve performance but take advantage of Solid State benefits (efficient power and lifespan) has been a goal. A transistor replacement for the 12AT7 tube was developed over a year ago to achieve this. Since then the new design has been undergoing test procedures and the required (critical) ‘listening’.

Available by year’s end, the stereo ‘Forte’ 50wpc power amplifier will operate in Class A for the first 5 watts. Efficient Speakers can take advantage of this but as current delivery is most important, the new amplifiers will employ sufficient power to drive even 1 Ohm loads. 8 capacitors with a total of 160,000uF, ensures plentiful and constant delivery.

More demanding speakers therefore will not be deprived of power or control.

Available in the new year, maximum benefit from Adagio’s twin analogue outputs can be obtained with the forthcoming 200wpc mono blocs. The monos will operate in Class A for the first 20 watts. Extremely high simulated valve circuit voltages (about 350V) are present, and due to this careful construction is required for safety reasons.