The Stellavox IDEM Mono Amplifier

The 'IDEM' is an intrinsic completely NFB-Free audio amplifier. It has a fully balanced design and operates according to a principal that is unknown in the audio sector.  

The development of this new amplifier principle took 25 years, naturally with interruptions and as a side project (there was a lot of other work to do, like helping my daughter to grow up.)

During this time, countless prototypes were created. Some of them were built solely to better understand basic principles (to see how this sounds with music) or to tinker with detailed ideas.

In 2022, the time had come. All problems had been solved. THD with the lowest values, mostly 3rd order, TIM (at least for our laboratory) not measurable and an output impedance of 0.02Ω (which we later improved by a factor of 4).

For the first listening test, we only had a mono amplifier prototype, which we called the ‘hotplate’ (not because it got hot, but because of its appearance). After listening for only 10 seconds, we realized: we had reached our goal. That sounds like a gross exaggeration. But for me and Carmine DeLuca, my colleague and driving force in recent years, it was an almost mystical moment that we will never forget, that repaid years of sweat and tears.

In the days that followed, we listened to all the musical delicacies that we couldn’t help but enjoy on the ‘hotplate’, in mono, mind you. We did some further measurement as well, but who cared anymore about them after having heard the hotplate! In the months that followed, we built the prototype called ‘Toaster’, now in stereo and with an improved thermal control circuitry and improved output impedance, and then we started engineering a new product, the STELLAVOX ‘idem’ monoblock.

The ‘idem’ is an intrinsic, completely NBF-free audio amplifier. It has a fully balanced design and operates according to a principle that is unknown in the audio sector. It’s tiring to say that only the best components, from the transformer to the speaker terminals (‘home-made’), are used. I assume that all devices in this price range are built in this spirit. Its efficiency when playing is equivalent to that of a standard AB amplifier. Its quiescent current is higher, so it will absorb slightly more energy during a pause in the music. This is where the standby mode comes in, which reduces this to a few milliamps while all capacities remain charged and the ‘low’ Class A current in the voltage amplifier continues to flow, so that it is immediately ready to play after ‘operation on’

 

For detailed descriptions and specifications on Stellavox products, please visit www.stellavox.swiss