Metrum Acoustics Forte Stereo Power Amplifier
Product Information
Metrum Forte - Tube Simulated Power Amplifier
"May the 'Forte' be with you"
Paired with Adagio 6 Moons comment ... "Particularly with loudspeakers like our ceramic-diaphragm Albedo Audio Aptica which will prioritize transient precision and resolution over body and density unless matched otherwise, the Forte's counterpoint hits the nail on the head".
As mentioned on previous Metrum Product pages – equipment does respond to Cabling improvement. System dependent of course.
Caution : Always Power off componentry before removing/installing Cables.
Amplification ... the driving force behind any Audio enthusiast's system. As usual a slightly different approach from Metrum .... designed to faithfully adhere to your music source and recordings.
Tubes/Valves or Solid State ?
Can the best of both Audio worlds create a Synergy 'where the whole is greater than the simple sum of its parts' ?
With an interest and background in Valve Hybrid design Amplifiers going back 2 decades, Cees Ruijtenberg’s preferred Valve has been the 12AT7. To evaluate their Dacs over the years, Metrum have used their own design Amplifiers. 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.
As with commercially available D/A chipsets (hence Industrial grade chips 1st and more recently 'Transient' in house designed D/A conversion modules), Cees is not content with existing valve components and therefore has worked to design a SS alternative – that matches or betters the favoured 12AT7.
"This tube offers great bandwidth and perfect gain".
But Triodes 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 some years ago to achieve this. Since then the new design underwent test procedures and the required (critical) ‘listening’ tests.
Stereo Forte operates in Class A for the first 10 watts.
Efficient Speakers can take advantage of this but as current delivery is most important, Forte employs sufficient power to drive even 1 Ohm loads.
8 capacitors with a total of 176,000uF, ensures plentiful and constant delivery.
More demanding Speakers therefore will not be deprived of power or control.
Digital Volume Control of course is now available to the Audio chain. Refer Adagio Page and Reviews ... as a Preamp Adagio competes with Analogue alternatives costings $20K+.
Forte Stereo Price : $6,995
Forte in Review
Witchdoctor : NZ
Dr. Varey investigates how Adagio + Forte perform in his listening room - with his preferred music. A great introduction to the design concepts behind Forte - for those unfamiliar. It's all about 'involvement' and Adagio combined with Forte ... do indeed pass muster. Richard is now a confirmed ...
6 Moons : Ireland
System matching and balancing acts are explored by Srajan Ebaen with Class leading components such as Nagra Jazz Preamp and Pass Labs XA30.8 Power.
"Since Adagio plus Forte make for near complete electronics (whatever transport will make comparatively little difference), we can talk about their combinant sound with good certainty.
The Adagio is a resolution freak, the Forte a musicality champ. As partners, they tango perfectly. On tonal balance and weight, the Forte exhibits what one expects of good tube preamps. On solidity and drive, it behaves like transistors.
Though it contains no tubes, it sounds like a tube hybrid without any self noise. So it beautifully delivers on Cees Ruijtenberg's design brief which 'clones' a 12AU7/12AT7 gain stage by running its transistors on 350V rails exactly like actual valves; but then improves over them.
To my knowledge, this approach is different. We've heard of solid-state amps with output transformers or autoformers, with high output impedance and tube-like transfer functions. How our Dutch man slices that ball across the net is different. Yet it works.
Particularly with loudspeakers like our ceramic-diaphragm Albedo Audio Aptica which will prioritize transient precision and resolution over body and density unless matched otherwise, the Forte's counterpoint " ...
Alpha-Audio : Netherlands
Jaap Veenstra test drives Forte with Adagio directing the bus.
"With Portishead we hear exactly what the purpose is - of all those strange effects. This is High-End without the sterility - as is sometimes (unfortunately) the case. This is High-End Audio with respect for the musicians. This is High-End as we would love to hear it. And with a price tag that is still a bit too good.
Forte thumbs its nose with two fingers up - to the top notch priced establishment" !
Review Translation :
Production unit - full throttle and pushed to the limit - no smoke !
Perfect Partners
View from the top.
Rear panel and connectivity
Heart of the beast :
Danger - High Voltage and heat sink.
Slow blow fuses.
Sans casework.
The favoured (slightly blurry) 12AT7 Valve.
Performance graph.
The 12AT7 in previous use.
The replacement. But what about listening ? ... "Same deep and wide space, same terrific control, same warmth without loosing any details". From someone who knows.
Distortion analysis. First the measurements ....... "same open loop bandwidth, same open loop gain, same feedback, same damping factor, same distortion but better noise figures.
The new design in the new casework. Silver ...