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Forte 150 - Powerfull mono blocks with KT 150 tubes

Creation of Forte 150

Before starting the Forte project, Auris Audio come to the realization that the a lack of sensitive speakers offered on the market demanded the design of amplifiers with great power and that the KT 150 tube amplifiers were mostly based on design upgrades of KT 88 and KT 120 circuit. To allow audiophiles to experience their favorite music in otherworldly dimensions, Auris Audio decided to create a completely new amplifier. After one year of hard work and development, the Forte 150 power amplifiers were born.


Auris Audio developed the Forte 150 mono blocks with RMS of 100W in a push-pull configuration with the 2 x KT 150 octal beam tetrode and 2 x 6SN7 dual triode tubes which there are covered by temperature resistant tempered glass, allowing for protection and easy maintenance. On the back are RCA/XLR (on demand ) inputs and speaker outputs at 4 Ω and 8 Ω. The output transformer on a double C-core sized for 200W enables signal linearity of 15Hz – 50kHz, offering plenty of power. Fine bias adjustment is positioned to provide the user a good overview at any moment. Mundorf capacitors and WBT silver connectors as well as silver wiring for the signal path manifest Auris Audio‘s exact aspirations towards providing the best possible sound without compromise.

KT 150 Tubes

With a massive plate dissipation of 70 watts the KT 150‘s tubes are most powerful octal beam tetrode ever produced. KT 150‘s glass envelope is a special egg shaped balloon that was developed to improve thermal dissipation and maintain a superior vacuum for the best sound, with no microphonics. The tone signature of the KT 150‘s is characterized by a strong bass signature with balance and claarity. Bass is tight, full and precise with a natural midrange and transparent High End clarity.

Tube Ballance Option

Fine Bias tube ballance option allows you to perform fine adjustment of the outputs tubes in order to fine-tune the sound of the tubes easily and remove any noise, hum or any interference if present, and it is positioned logically to provide the user a good overview at any moment. Each output tube has separate instrument to allow you a complete visual control of the adjusted bias at every moment.


Transformers are the essence of the quality, and therefore products of Auris Audio contain only manually wound transformers on a double C-core. Every single transformer is manufactured in compliance with strictly defined requirements, thus providing almost a linear characteristic in the whole acoustic/sound range. The transformers are designed for 200W which enables signal linearity of 15Hz to 50 kHz, offering a lot of power.


As manufacturers and audiophiles, Auris Audio always seeking perfection in sound and appearance and we know that High-End does not allow any compromises, in this regard The Forte 150‘s level of detail is very high and clear which provide you superior sound with greater finesse. The forte 150 mono blocks offered excellent tonality, microphonics and has the power to drive any type of the speakers. Tubes 6SN7 have airy treble and midrange, untill KT 150 tubes are powerful, dynamic and technically superior.


The Auris Audio uses latest innovative technology in designing Forte 150 Mono Blocks: Forte 150 has Double C core Transformers of 200W Specialy created a modern approach in SMPS in heating Fine Tube Bias adjustment All circle capacitors are Mundorf fine silver wire and premium WBT silver connectors are used for the interconnection The selected premium components guarantee an extraordinary experience while wooden sides cushion the vibrations and reduce the outside impact on the sound. KT 150 octal beam tetrode tubes along with 6SN7 double triode tubes has ability to provide large soundstage use.
Forte 150 mono blocks are heavy, but very simple to use. Plug the music source at analog input, and connect the mono blocks with your speakers and everything is ready to start enjoying the desirable sound.


Infinity is untouchable and these days audiophiles are seeking out an endless, un-compromised design. With this approach, Auris Auido designed the Forte 150 contours of the infinity sign which are basis of this recognizable design while quality and a large VU meter are iconic on the cake. Based on experience Auris Audio philosophy is rooted in superior design, best materials and skill of making. The Forte 150 was created with one goal in mind and that is to provide full enjoyment to the most demanding audiophiles delivered them supreme quality. Attention to detail and ability to make all the important steps in house gave us desired unique perfection.


The Forte 150 mono blocks are large and made full of an aluminum chassis with measures of 510 mm wide x 350 mm long x 340 mm tall and with wooden side panels to reduce any vibration. The weight of this musical beast is 27,5 kg. 

Product Specification

Output power RMS 100W / Music 150W
Class operation A/AB
Configuration Push - Pull
Vacuum tubes 2 x KT150, 2 x 6SN7
Inputs sensitivity 2, 3Vrms
Input impedance 47kΩ
Inputs RCA/XLR optional
Outputs 4 & 8Ω
Frequency response 15Hz – 50kHz
S/N <91dB
THD% 1kHz / 1W=0,08% / Pmax=3.3%
Cables Not Included
Power consumption 250VA
Dimensions W x L x H 510 X 350 X 340
Weight per piece 27.5kg


„I was suprised when I played the first few songs throught the Auris Audio Forte 150 power amplifiers. The absence of archaic, warmish and saturated sound imprints proved to be a refreshingly positive experience. The Forte 150 didn‘t force itself with the sonic self-imprint often associated with most pedestrain power tube amplifiers. It rather explored the exhilarating, yet natural side of high-end audio reproduction. With so many product on the market, one doesn‘t really know what to expect when certain products arrive for review, but it is always encouraging to discover new, and potent performers." - Matej Isak, Mono and Stereo