PURIFI

PURIFI, a startup from Denmark, is launching a freshly designed line of loudspeaker drivers and new power amplifier modules at the same time. The first amplifier product is a 400W class D module that uses PURIFI’s Eigentakt control scheme, which delivers a stated THD and IMD below -115dB (0.00017%) at all levels and frequencies. Its negligible output impedance insures that the +/-0.01dB frequency response is guaranteed for all loudspeaker loads. The first loudspeaker product is a 6.5” driver with a +/-10mm linear stroke whose IMD is said to be around 20dB lower than that of comparably specified drivers.

For a new company to attack two such disparate lines of work becomes a bit less unusual when one considers the names behind the venture: Peter Lyngdorf, Bruno Putzeys and Lars Risbo. All three have a proven track record in both amplifiers and loudspeakers.

The three started PURIFI because of a shared conviction that real improvements in musical experience can only be had by addressing the technical fundamentals. “The high end audio industry has historically had trouble coming to grips with basics like distortion, tacitly deciding to ignore the problem instead,” notes Putzeys. “It’s not just electronics,” adds Risbo, “loudspeaker units have some clearly identifiable distortion mechanisms that just sit there waiting to be solved”. Backed by Peter Lyngdorf, the pair have thrown themselves onto a project to take on distortion in amplifiers and loudspeakers alike.

In both cases their approach is highly systematic and mathematical. The philosophy is that while simulations are useful virtual prototyping tools, they do not provide any deeper insight than trying things out in the lab. By contrast, mathematical descriptions of the problem often end up spelling out the solution.

Lars Risbo: This goes quite a bit into our backgrounds and how we got together ‘as a band’. Bruno and I have been admiring each other the last 15-20 years or so and for long talked about doing something together. I have always been interested in speakers and done some DIY when I was young (and kid together with my father - using old super sensitive Peerless drivers). In 2009, I started a project called ‘SmartAmp’ in Texas Instruments and that required me to dig very deep into speaker drivers - especially their nonlinear properties and thermal modelling. We began using Carsten as a consultant and the first thoughts and visions about doing better drivers emerged. When Purifi started in 2014, I leased som desk and lab space at Carstens PointSource company (Carsten worked at Peerless for about 17 years until Tymphany closed the Danish site down in 2009 and Carsten started PointSource). Bruno and I initially wanted to do fully digital/electronic correction of speaker nonlinearities (a la Klippel and beyond). The 2 year of research lead to discovery of numerous ways to improve drivers drastically. We decided then to team up with Carsten and develop the world’s lowest distortion drivers and start a new company selling them (Purifi Transducer Technology). This became a close team effort combining all our skills. We still have longer term plans for digital compensation since the total system cost can be reduced by solving the problems in the best suited domain (digital, mechanical, magnetic etc) but we will initially expand our driver portfolio to a full line.

PURIFI’s amplifier modules are industrialized by the team previously responsible for rolling out Texas Instruments’ high power class D amplifier chip range. For the drivers the company has joined forces with Carsten Tinggaard (PointSource Acoustics and formerly Peerless) who for the past two decades has been behind some of the most recognizable drive units in the industry.

Here are the names who stands behind PURIFI brand:

Bruno Putzeys, Co-Founder
Inventor of UcD (Philips), probably still the most widely used class-D amplifier for upmarket audio products. Inventor of Ncore (Hypex), which is generally considered the first class-D amplifier to successfully compete with class-A on audio performance. Developed high performance A/D and D/A converter designs for Grimm and Mola-Mola. Co-founder for Kii Audio. Holds 8 patents and multiple patent disclosures
Lars Risbo, Co-Founder
Pioneered direct switching PCM-PWM audio amplifiers as founder of Toccata Technology, later acquired by Texas Instruments. Elected TI Fellow (2012) and Audio CTO (2013). Research interests include digital signal processing, system-level and signal chain optimization, oversampled data converters, transducers and mixed-signal architectures. Ph.D from DTU (1994). Holds >30 US granted patent families
Carsten Tinggaard, Co-Owner (PURIFI Transducer Technology)
Founder and owner of PointSource Acoustics (2009). Previously Product Manager for Danish Sound Technology (2003) and CTO of Tymphany Denmark (2005) responsible for establishing R&D Denmark facility covering Peerless, Vifa and Scan-Speak brands. Spearheaded Peerless tech. transfer to China manufacturing facilities. Co-owner of PURIFI Transducer Technology (2017), a subsidiary of PURIFI
Peter Lyngdorf, Co-Founder
Owner of Lyngdorf Family Holding, Hi Fi Klubben, DALI and Steinway Lyngdorf. The group has >1000 employees and multiple factories in Denmark and China. Former owner several audio companies including NAD Electronics and Snell Acoustics. Driver of Digital Room Compensation technology from Snell DSP 1000 (1993) through NAD, TacT Audio and now Lyngdorf RoomPerfect
Claus Neesgaard, Co-Owner, Director
Held Business/R&D Management, Product Definer and Systems Architect roles (Texas instruments) responsible for launching and growing TI’s TAS/TPA-series class D amplifier portfolio. Stints as head of TI’s Audio DSP product line, leading the transition into streaming-based system solutions. In early career, developed several core innovations in class D amplification for Toccata Technology leading to the acquisition by TI in 2000. M.Sc.E from DTU (1998). Holds 6 US patents
Kim Madsen, Applications Manager
Specialized in audio and power electronics. Held roles as Applications Manager, Product Definer and Lead Systems Engineer (Texas Instrument) most recently focused on TI’s Automotive Amplifier portfolio. Developed mil-spec power modules for the Ariane 5 Rocket (Alcatel) and several fighter aircrafts (Dynatech). M.Sc.EE (1991) from DTU. Holds 5 US patents and several patent disclosures
Søren Poulsen, R&D
Held roles as Product Definer and Lead Systems Engineer (Texas Instruments) especially focused on performance- and reliability optimization of TI’s mid/high power Audio IC’s. Owned definition and architecture development of worlds highest-power, highest-performance Integrated Circuit (IC) Amplifier. Ph.D from DTU (2004). Holds 5 US patents and several publications
Morten Halvorsen, R&D Acoustics (PURIFI Transducer Tech.)
Worked as Senior Acoustic Engineer at PointSource Acoustics. Co-developed both the loudspeakers and sound unit of the Montana Sound and SoundBy PointSource products. Specialized in electromagnetic simulations, measurements and procedure optimization. Researched force factor modulation, developing measurement equipment and simulation models. Results presented at AES 138. M.Sc.E.E. with specialization in acoustics from DTU (2014)