Auris Fortissimo

• Designed in Push-Pull technology, combines brutal power with sweet mid-range, exceptional delicacy, and everything one could expect from a truly hi-end equipment
• A pair of KT-120s allows easy selection of wide range of speakers
• Manually adjustable bias, reduces the noise and expands the life time of tubes
• A lovely electronic work of art, beautiful to behold and elegant all around

A Veritable Beast

Auris Audio Fortissimo is made to thrill audio enthusiasts whose favorite notes can be found in more dynamic music. Great Orchestra, Blues, Rock and Fortissimo are made for each other.

Extremely strong integrated amp, Fortissimo puts out 100 watts per channel. A pair of KT-120s output tubes that operate in ultralinear pentode mode, allows easy selection of wide range of speakers. For example, driving passive monitor ATC SCM 100 speakers might be a challenge for many amps, but it is „a walk in the park" for this Auris powerhouse. 

A sound great like Fortissimo produces it is not achieved by accident: the Fortissimo uses a quartet of Tung-Sol KT-120 tubes, working in a push-pull configuration in the A/AB class along with four ECC99 double triodes, provided by JJ Electronic. Its frequency response extends from 15 Hz to 50 kHz, and the signal to noise ratio is over 85 dB. Output tubes have manually adjustable bias, so the lifetime of tubes can be expanded and noise reduced, by adequate adjustment of it.

Right after the first listening, you can conclude that it is an exceptional sounding amplifier, with the unique design.

Sound Performance

The way Fortissimo shifts and builds a realistic musical event in the room is the most impressive thing about it. The amplifier has the level of sound quality that is unreachable for most amplifiers on the market, regardless of the price, since it preserves the very best  attributes of „tube sound", while adding extension and control in bass:

• The sound is described as based on solid, deep and meety bass 
• It shows very sophisticated midrange with clean and natural vocals 
• The sound is not overheated and the vocals are phenomenal 

The most impressive thing about it is that, while listening to it, you have a feeling the musicians are playing only for you, in your room. You can easily hear all the ancillary noises made by the cellist, mainly breathing and an occasional sigh. Interestingly, these human noises are distinctly separate from the cello in three-dimensional space, hanging somewhat above and in front of the instrument.

The other area in which the Fortissimo strutted its stuff, is in its ability to cast a lovely glow on the midrange, while placing just enough music to liven up the sound of the speakers.

Bias Adjustment

The output tubes need to be biased at initial setup and after the amplifier have gotten warmed up a bit. It is an easy task involving turning small potentiometers, located on the top plate and behind the tubes. Once adjusted, tubes retain their desired bias current for some time, but it can be re-adjusted if necessary.

A small miliampermeter on top plate shows values for each tube separately ( V1, V2, V3, V4 ). When the stable value 55 mA is reached, measuring can be repeated after 1 hour.

Design

Fortissimo is a perfect example of a hi-end tube amplifier made in a truly uncompromising manner, designed with a lot of courage and no visible restrictions. It is also an electronic work of art, where each element is refined and beautiful. 

The huge casing is made entirely of metal, adorned with wooden side panels with the company logo. The amp is equipped with an input selector, volume control, remote and a basic system of setting the output tubes bias. At the back, there are three unbalanced input and one XLR input, loudspeaker outputs with 4 and 8 Ω terminals and a three-bay power socket with the main switch.

If you happen to encounter one in a room loaded with gear, your eyes will leap at Fortissimo.

Use

The tubes are properly marked, each of them has its own place, and the only thing you have to do is to match the tube's number to the slot. You just can't make a mistake here.

he start up procedure is recommended, during which the tubes are heated in a stable and safe way. When the amplifier is ready for use, it is indicated by a loud click, and it usualy takes about 40 minutes to heat up. Afterwards it will be completely ready for full musical enjoyment. 

During the listening sessions, you will realize that this is one of these amplifiers you don't mess with. Just be careful with the volume control... Depending on the speakers, the so-called realistic volume level can be reached as early as 9 or 10 o'clock.

Footprint

Auris Fortissimo is all about the size – big sound, big amplifier. It is really big, heavy and tall: 490 mm (W), 447 mm (L), 33 5mm (H) and the weight is 30kg. So you‘d have to prepare a good rack for it.